Incremented version to 8.1.2

Weights within the PSK are now sorted by point_index and have their weights normalized.

.gitattributes

@@ -0,0 +1,4 @@
+*.psk filter=lfs diff=lfs merge=lfs -text
+*.psa filter=lfs diff=lfs merge=lfs -text
+*.pskx filter=lfs diff=lfs merge=lfs -text
+*.blend filter=lfs diff=lfs merge=lfs -text

.github/workflows/main.yml

@@ -1,4 +1,4 @@
-name: Build Extension
+name: tests
 
 on:
   workflow_dispatch:
@@ -10,43 +10,64 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        blender-version: [ 4.4 ]
     env:
-      BLENDER_VERSION: blender-4.2.0-linux-x64
       ADDON_NAME: io_scene_psk_psa
     steps:
       - uses: actions/checkout@v3
+        with:
+          lfs: true
+      - name: Checkout LFS objects
+        run: git lfs checkout
       - uses: SebRollen/toml-action@v1.2.0
         id: read_manifest
         with:
           file: '${{ env.ADDON_NAME }}/blender_manifest.toml'
           field: 'version'
-      - name: Set derived environment variables
-        run: |
-          echo "BLENDER_FILENAME=${{ env.BLENDER_VERSION }}.tar.xz" >> $GITHUB_ENV
-          echo "BLENDER_URL=https://mirrors.iu13.net/blender/release/Blender4.2/${{ env.BLENDER_VERSION }}.tar.xz" >> $GITHUB_ENV
       - name: Install Blender Dependencies
         run: |
+          sudo apt-get update -y
           sudo apt-get install libxxf86vm-dev -y
           sudo apt-get install libxfixes3 -y
           sudo apt-get install libxi-dev -y
           sudo apt-get install libxkbcommon-x11-0 -y
           sudo apt-get install libgl1 -y
           sudo apt-get install libglx-mesa0 -y
-      - name: Download & Extract Blender
+          sudo apt-get install python3 -y
+      - name: Install Requirements
         run: |
-          wget -q $BLENDER_URL
-          tar -xf $BLENDER_FILENAME
-          rm -rf $BLENDER_FILENAME
-      - name: Add Blender executable to path
+          python3 -m pip install --upgrade pip
+          python3 -m pip install virtualenv
+          python3 -m virtualenv venv
+          source venv/bin/activate
+          pip install pytest-blender
+          pip install blender-downloader
+      - name: Install Blender
         run: |
-          echo "${{ github.workspace }}/${{ env.BLENDER_VERSION }}/" >> $GITHUB_PATH
+          source venv/bin/activate
+          blender_executable="$(blender-downloader ${{ matrix.blender-version }} --extract --print-blender-executable)"
+          echo "BLENDER_EXECUTABLE=${blender_executable}" >> $GITHUB_ENV
+          blender_python="$(pytest-blender --blender-executable "$blender_executable")"
+          echo "BLENDER_PYTHON=${blender_python}" >> $GITHUB_ENV
+          # Write the BLENDER_PYTHON path to the console for debugging
+          # Deactivate the virtualenv to avoid conflicts with the system python
+          deactivate
+          $blender_python -m ensurepip
+          $blender_python -m pip install -r tests/requirements.txt
       - name: Build extension
         run: |
           pushd ./${{ env.ADDON_NAME }}
-          blender --command extension build
+          # Run blender using the environment variable set by the action
+          ${{ env.BLENDER_EXECUTABLE }} --command extension build
           mkdir artifact
           unzip -q ${{ env.ADDON_NAME }}-${{ steps.read_manifest.outputs.value }}.zip -d ./artifact
           popd
+      - name: Run tests
+        run: |
+          source venv/bin/activate
+          pytest -svv tests --blender-addons-dirs .
       - name: Archive addon
         uses: actions/upload-artifact@v4
         with:

.gitignore

@@ -105,3 +105,4 @@ venv.bak/
 
 # PyCharm
 .idea
+*.blend1

.vscode/tasks.json

@@ -0,0 +1,17 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "io_scene_psk_psa: test",
+            "type": "shell",
+            "command": "docker run -it --volume ${PWD}:/io_scene_psk_psa --volume ${PWD}/io_scene_psk_psa:/addons/io_scene_psk_psa --volume ${PWD}/tests:/tests  $(docker build -q .)",
+            "problemMatcher": [],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        }
+    ]
+}

Dockerfile

@@ -0,0 +1,34 @@
+FROM ubuntu:22.04
+
+ARG BLENDER_VERSION=4.4
+
+RUN apt-get update -y && \
+    apt-get install -y libxxf86vm-dev libxfixes3 libxi-dev libxkbcommon-x11-0 libgl1 libglx-mesa0 python3 python3-pip \
+    libxrender1 libsm6
+
+RUN pip install --upgrade pip
+RUN pip install pytest-blender
+RUN pip install blender-downloader
+
+# Set BLENDER_EXECUTABLE and BLENDER_PYTHON as environment variables
+RUN BLENDER_EXECUTABLE=$(blender-downloader $BLENDER_VERSION --extract --remove-compressed --print-blender-executable) && \
+    BLENDER_PYTHON=$(pytest-blender --blender-executable "${BLENDER_EXECUTABLE}") && \
+    echo "export BLENDER_EXECUTABLE=${BLENDER_EXECUTABLE}" >> /etc/environment && \
+    echo "export BLENDER_PYTHON=${BLENDER_PYTHON}" >> /etc/environment && \
+    echo $BLENDER_EXECUTABLE > /blender_executable_path
+
+RUN pip install pytest-cov
+
+# Source the environment variables and install Python dependencies
+RUN . /etc/environment && \
+    $BLENDER_PYTHON -m ensurepip && \
+    $BLENDER_PYTHON -m pip install pytest pytest-cov
+
+# Persist BLENDER_EXECUTABLE as an environment variable
+RUN echo $(cat /blender_executable_path) > /tmp/blender_executable_path_env && \
+    export BLENDER_EXECUTABLE=$(cat /tmp/blender_executable_path_env)
+ENV BLENDER_EXECUTABLE /tmp/blender_executable_path_env
+
+ENTRYPOINT [ "/bin/bash", "-c" ]
+WORKDIR /io_scene_psk_psa
+CMD ["source tests/test.sh"]

README.md

@@ -1,6 +1,5 @@
-[![Blender](https://img.shields.io/badge/Blender->=2.9-blue?logo=blender&logoColor=white)](https://www.blender.org/download/ "Download Blender")
-[![GitHub release](https://img.shields.io/github/release/DarklightGames/io_scene_psk_psa?include_prereleases=&sort=semver&color=blue)](https://github.com/DarklightGames/io_scene_psk_psa/releases/)
-[![Build Extension](https://github.com/DarklightGames/io_scene_psk_psa/actions/workflows/main.yml/badge.svg)](https://github.com/DarklightGames/io_scene_psk_psa/actions/workflows/main.yml)
+[![Blender](https://img.shields.io/badge/Blender%20Extension-Download-blue?logo=blender&logoColor=white)](https://extensions.blender.org/add-ons/io-scene-psk-psa/ "Download Blender")
+[![tests](https://github.com/DarklightGames/io_scene_psk_psa/actions/workflows/main.yml/badge.svg)](https://github.com/DarklightGames/io_scene_psk_psa/actions/workflows/main.yml)
 
 [![ko-fi](https://ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/L4L3853VR)
 
@@ -10,38 +9,19 @@ This software is licensed under the [GPLv3](https://www.gnu.org/licenses/gpl-3.0
 
 # Features
 * Full PSK/PSA import and export capabilities.
-* Non-standard file section data is supported for import only (vertex normals, extra UV channels, vertex colors, shape keys).
+* Non-standard file section data (.pskx) is supported for import only (vertex normals, extra UV channels, vertex colors, shape keys).
 * Fine-grained PSA sequence importing for efficient workflow when working with large PSA files.
 * PSA sequence metadata (e.g., frame rate) is preserved on import, allowing this data to be reused on export.
-* Specific bone collections can be excluded from PSK/PSA export (useful for excluding non-contributing bones such as IK controllers).
+* [Bone collections](https://docs.blender.org/manual/en/latest/animation/armatures/bones/bone_collections.html#bone-collections) can be excluded from PSK/PSA export (useful for excluding non-contributing bones such as IK controllers).
 * PSA sequences can be exported directly from actions or delineated using a scene's [timeline markers](https://docs.blender.org/manual/en/latest/animation/markers.html), pose markers, or NLA track strips, allowing direct use of the [NLA](https://docs.blender.org/manual/en/latest/editors/nla/index.html) when creating sequences.
-* Manual re-ordering of material slots when exporting multiple mesh objects.
+* Manual re-ordering of material slots.
+* Multiple armature objects can be exported to a single PSK or PSA file, allowing seamless use of [action slots](https://docs.blender.org/manual/en/latest/animation/actions.html#action-slots).
+* Support for exporting instance collections.
 
 # Installation
-For Blender 4.2 and higher, it is recommended to download the latest version from the [Blender Extensions](https://extensions.blender.org/add-ons/io-scene-psk-psa/) platform.
+For Blender 4.2 and higher, download the latest version from the [Blender Extensions](https://extensions.blender.org/add-ons/io-scene-psk-psa/) platform.
 
-For Blender 4.1 and lower, you can install the addon manually by following these steps:
-
-1. Download the .zip file of the latest compatible version for your Blender version (see [Legacy Compatibility](#legacy-compatibility)).
-2. Open Blender.
-3. Navigate to the Blender Preferences (`Edit` > `Preferences`).
-4. Select the `Add-ons` tab.
-5. Click the `Install...` button.
-6. Select the .zip file that you downloaded earlier and click `Install Add-on`.
-7. Enable the newly added `Import-Export: PSK/PSA Importer/Exporter` addon.
-
-# Legacy Compatibility
-
-Below is a table of the latest addon versions that are compatible with older versions of Blender. These versions are no longer maintained and may contain bugs that have been fixed in newer versions. It is recommended to use the latest version of the addon for the best experience.
-
-Critical bug fixes may be issued for legacy addon versions that are under [Blender's LTS maintenance period](https://www.blender.org/download/lts/). Once the LTS period has ended, legacy addon versions will no longer be supported by the maintainers of this repository, although the releases will still be available for download.
-
-| Blender Version| Addon Version                                                                  | Long Term Support |
-|-|--------------------------------------------------------------------------------|-----------------|
-| [4.1](https://www.blender.org/download/releases/4-1/)        | [7.0.0](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/7.0.0) | No              |
-| [4.0](https://www.blender.org/download/releases/4-0/)        | [6.2.1](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/6.2.1) | No              |
-| [3.4 - 3.6](https://www.blender.org/download/lts/3-6/)       | [5.0.6](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/5.0.6) | June 2025       |
-| [2.93 - 3.3](https://www.blender.org/download/releases/3-3/) | [4.3.0](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/4.3.0) | September 2024  |
+For Blender 4.1 and lower, see [Legacy Compatibility](#legacy-compatibility).
 
 # Usage
 ## Exporting a PSK
@@ -69,13 +49,45 @@ Critical bug fixes may be issued for legacy addon versions that are under [Blend
 # FAQ
 
 ## Why can't I see the animations imported from my PSA?
-Simply importing an animation into the scene will not automatically apply the action to the armature. This is in part because a PSA can have multiple sequences imported from it, and also that it's generally bad form for importers to modify the scene when they don't need to.
+Simply importing an animation into the scene will not automatically apply the action to the armature. This is in part because a PSA can have multiple sequences imported from it, and also that it's generally bad form for importers to modify the scene in ways that the user may not expect.
 
 The PSA importer creates [Actions](https://docs.blender.org/manual/en/latest/animation/actions.html) for each of the selected sequences in the PSA. These actions can be applied to your armature via the [Action Editor](https://docs.blender.org/manual/en/latest/editors/dope_sheet/action.html) or [NLA Editor](https://docs.blender.org/manual/en/latest/editors/nla/index.html).
 
+## Why are imported PSKs too big/too small?
+The PSK format, unlike other more modern formats, has no explicit or implicit unit system. Each game has its own convention as to what the base distance unit will represent. As such, this addon makes no assumptions as to the unit scale of the imported PSKs. If you think that your models are being imported into Blender either too big or too small, there are a couple ways to remedy this.
+
+The method I prefer is to simply change the Blender [scene properties](https://docs.blender.org/manual/en/4.4/scene_layout/scene/properties.html#units) to match the unit system and scale for the game you're using. This is non-destructive and ensures that the unit scaling of any PSK or PSA exports from Blender will match the source file from which it was derived.
+
+The second option is to simply change the `Scale` value on the PSK import dialog. This will scale the armature by the factor provided. Note that this is more destructive, but may be preferable if you don't intend on exporting PSKs or PSAs to a game engine.
+
+## How do I control shading for PSK exports?
+The PSK format does not support vertex normals and instead uses [smoothing groups](https://en.wikipedia.org/wiki/Smoothing_group) to control shading. Note that a mesh's Custom Split Normals Data will be ignored when exporting to PSK. Therefore, the best way to control shading is to use sharp edges and the Edge Split modifier.
+
 ## Why are the mesh normals not accurate when importing a PSK extracted from [UE Viewer](https://www.gildor.org/en/projects/umodel)?
 If preserving the mesh normals of models is important for your workflow, it is *not recommended* to export PSK files from UE Viewer. This is because UE Viewer makes no attempt to reconstruct the original [smoothing groups](https://en.wikipedia.org/wiki/Smoothing_group). As a result, the normals of imported PSK files will be incorrect when imported into Blender and will need to be manually fixed.
 
-As a workaround, it is recommended to export [glTF](https://en.wikipedia.org/wiki/GlTF) meshes out of UE Viewer instead, since the glTF format has support for explicit normals and UE Viewer can correctly preserve the mesh normals on export. Note, however, that the imported glTF armature may have it's bones oriented incorrectly when imported into Blender. To mitigate this, you can combine the armature of PSK and the mesh of the glTF for best results.
+There is a [pull request](https://github.com/gildor2/UEViewer/pull/277) to add support for exporting explicit normals from UE Viewer, although UEViewer's maintainer has seemingly abandoned the project.
 
-There is also an open pull request to add support for exporting explicit normals from UE Viewer in the future: https://github.com/gildor2/UEViewer/pull/277.
+# Legacy Compatibility
+Below is a table of the latest addon versions that are compatible with older versions of Blender. These versions are no longer maintained and may contain bugs that have been fixed in newer versions. It is recommended to use the latest version of the addon for the best experience.
+
+Critical bug fixes may be issued for legacy addon versions that are under [Blender's LTS maintenance period](https://www.blender.org/download/lts/). Once the LTS period has ended, legacy addon versions will no longer be supported by the maintainers of this repository, although the releases will still be available for download.
+
+| Blender Version| Addon Version                                                                  | Long Term Support |
+|-|--------------------------------------------------------------------------------|-----------------|
+| [4.1](https://www.blender.org/download/releases/4-1/)        | [7.0.0](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/7.0.0) | No              |
+| [4.0](https://www.blender.org/download/releases/4-0/)        | [6.2.1](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/6.2.1) | No              |
+| [3.4 - 3.6](https://www.blender.org/download/lts/3-6/)       | [5.0.6](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/5.0.6) | June 2025       |
+| [2.93 - 3.3](https://www.blender.org/download/releases/3-3/) | [4.3.0](https://github.com/DarklightGames/io_scene_psk_psa/releases/tag/4.3.0) | ~~September 2024~~  |
+
+
+# Testing
+To execute the automated tests, run:
+
+```
+./test.sh
+````
+
+This will create a [Docker](https://www.docker.com/) container with and run the tests inside it. The tests are executed using [pytest](https://docs.pytest.org/en/stable/) and the results will be displayed in the terminal.
+
+For now, the tests are not exhaustive and primarily focus on sanity checking the most common use cases (PSK & PSA import). New tests will likely be made to cover new features and prevent further regressions of reported issues.

io_scene_psk_psa/__init__.py

@@ -36,40 +36,52 @@ if 'bpy' in locals():
 else:
     from .shared import data as shared_data, types as shared_types, helpers as shared_helpers
     from .shared import dfs as shared_dfs, ui as shared_ui
-    from .psk import data as psk_data, builder as psk_builder, writer as psk_writer, \
-    importer as psk_importer, properties as psk_properties
+    from .psk import (
+        builder as psk_builder,
+        data as psk_data,
+        importer as psk_importer,
+        properties as psk_properties,
+        writer as psk_writer,
+    )
     from .psk import reader as psk_reader, ui as psk_ui
-    from .psk.export import properties as psk_export_properties, ui as psk_export_ui, \
-        operators as psk_export_operators
+    from .psk.export import (
+        operators as psk_export_operators,
+        properties as psk_export_properties,
+        ui as psk_export_ui,
+    )
     from .psk.import_ import operators as psk_import_operators
 
-    from .psa import config as psa_config, data as psa_data, writer as psa_writer, reader as psa_reader, \
-        builder as psa_builder, importer as psa_importer
-    from .psa.export import properties as psa_export_properties, ui as psa_export_ui, \
-        operators as psa_export_operators
+    from .psa import (
+        config as psa_config,
+        data as psa_data,
+        writer as psa_writer,
+        reader as psa_reader,
+        builder as psa_builder,
+        importer as psa_importer,
+    )
+    from .psa.export import (
+        properties as psa_export_properties,
+        ui as psa_export_ui,
+        operators as psa_export_operators,
+    )
     from .psa.import_ import operators as psa_import_operators
     from .psa.import_ import ui as psa_import_ui, properties as psa_import_properties
 
 import bpy
 from bpy.props import PointerProperty
 
-# TODO: just here so that it's not unreferenced and removed on save.
-if [shared_data, shared_helpers, psk_data, psk_reader, psk_writer, psk_builder, psk_importer, psa_data, psa_config,
-    psa_reader, psa_writer, psa_builder, psa_importer]:
-    pass
-
-classes = shared_types.classes +\
-          psk_properties.classes +\
-          psk_ui.classes +\
-          psk_import_operators.classes +\
-          psk_export_properties.classes +\
-          psk_export_operators.classes +\
+classes = shared_types.classes + \
+          psk_properties.classes + \
+          psk_ui.classes + \
+          psk_import_operators.classes + \
+          psk_export_properties.classes + \
+          psk_export_operators.classes + \
           psk_export_ui.classes + \
-          psa_export_properties.classes +\
-          psa_export_operators.classes +\
+          psa_export_properties.classes + \
+          psa_export_operators.classes + \
           psa_export_ui.classes + \
-          psa_import_properties.classes +\
-          psa_import_operators.classes +\
+          psa_import_properties.classes + \
+          psa_import_operators.classes + \
           psa_import_ui.classes
 
 

io_scene_psk_psa/blender_manifest.toml

@@ -1,6 +1,6 @@
 schema_version = "1.0.0"
 id = "io_scene_psk_psa"
-version = "8.0.0"
+version = "8.1.2"
 name = "Unreal PSK/PSA (.psk/.psa)"
 tagline = "Import and export PSK and PSA files used in Unreal Engine"
 maintainer = "Colin Basnett <cmbasnett@gmail.com>"
@@ -24,4 +24,4 @@ paths_exclude_pattern = [
 ]
 
 [permissions]
-files = "Import/export PSK and PSA files from/to disk"
+files = "Read and write PSK and PSA files from and to disk"

io_scene_psk_psa/psa/builder.py

@@ -1,10 +1,10 @@
-from typing import Optional
+from bpy.types import Action, AnimData, Context, Object, PoseBone
 
-from bpy.types import Bone, Action, PoseBone
-from mathutils import Vector
+from .data import Psa
+from typing import Dict, List, Optional, Tuple
+from mathutils import Matrix, Quaternion, Vector
 
-from .data import *
-from ..shared.helpers import *
+from ..shared.helpers import create_psx_bones, get_coordinate_system_transform
 
 
 class PsaBuildSequence:
@@ -26,115 +26,108 @@ class PsaBuildSequence:
 
 class PsaBuildOptions:
     def __init__(self):
+        self.armature_objects: List[Object] = []
         self.animation_data: Optional[AnimData] = None
         self.sequences: List[PsaBuildSequence] = []
         self.bone_filter_mode: str = 'ALL'
-        self.bone_collection_indices: List[int] = []
+        self.bone_collection_indices: List[Tuple[str, int]] = []
         self.sequence_name_prefix: str = ''
         self.sequence_name_suffix: str = ''
-        self.root_motion: bool = False
         self.scale = 1.0
         self.sampling_mode: str = 'INTERPOLATED'  # One of ('INTERPOLATED', 'SUBFRAME')
+        self.export_space = 'WORLD'
+        self.forward_axis = 'X'
+        self.up_axis = 'Z'
+        self.root_bone_name = 'ROOT'
 
 
-def _get_pose_bone_location_and_rotation(pose_bone: PoseBone, armature_object: Object, options: PsaBuildOptions):
-    if pose_bone.parent is not None:
+def _get_pose_bone_location_and_rotation(
+        pose_bone: Optional[PoseBone],
+        armature_object: Optional[Object],
+        export_space: str,
+        scale: Vector,
+        coordinate_system_transform: Matrix,
+        has_false_root_bone: bool,
+) -> Tuple[Vector, Quaternion]:
+    is_false_root_bone = pose_bone is None and armature_object is None
+
+    if is_false_root_bone:
+        pose_bone_matrix = coordinate_system_transform
+    elif pose_bone.parent is not None:
         pose_bone_matrix = pose_bone.matrix
         pose_bone_parent_matrix = pose_bone.parent.matrix
         pose_bone_matrix = pose_bone_parent_matrix.inverted() @ pose_bone_matrix
     else:
-        if options.root_motion:
-            # Get the bone's pose matrix, taking the armature object's world matrix into account.
+        # Root bone
+        if has_false_root_bone:
             pose_bone_matrix = armature_object.matrix_world @ pose_bone.matrix
         else:
-            # Use the bind pose matrix for the root bone.
-            pose_bone_matrix = pose_bone.matrix
+            # Get the bone's pose matrix and transform it into the export space.
+            # In the case of an 'ARMATURE' export space, this will be the inverse of armature object's world matrix.
+            # Otherwise, it will be the identity matrix.
+            match export_space:
+                case 'ARMATURE':
+                    pose_bone_matrix = pose_bone.matrix
+                case 'WORLD':
+                    pose_bone_matrix = armature_object.matrix_world @ pose_bone.matrix
+                case 'ROOT':
+                    pose_bone_matrix = Matrix.Identity(4)
+                case _:
+                    assert False, f'Invalid export space: {export_space}'
+
+            # The root bone is the only bone that should be transformed by the coordinate system transform, since all
+            # other bones are relative to their parent bones.
+            pose_bone_matrix = coordinate_system_transform @ pose_bone_matrix
 
     location = pose_bone_matrix.to_translation()
     rotation = pose_bone_matrix.to_quaternion().normalized()
 
-    location *= options.scale
+    # Don't apply scale to the root bone of armatures if we have a false root.
+    if not has_false_root_bone or (pose_bone is None or pose_bone.parent is not None):
+        location *= scale
 
-    if pose_bone.parent is not None:
+    if has_false_root_bone:
+        is_child_bone = not is_false_root_bone
+    else:
+        is_child_bone = pose_bone.parent is not None
+
+    if is_child_bone:
         rotation.conjugate()
 
     return location, rotation
 
 
-def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
-    active_object = context.view_layer.objects.active
-
+def build_psa(context: Context, options: PsaBuildOptions) -> Psa:
     psa = Psa()
 
-    armature_object = active_object
-    armature_data = typing.cast(Armature, armature_object.data)
-    bones: List[Bone] = list(iter(armature_data.bones))
-
-    # The order of the armature bones and the pose bones is not guaranteed to be the same.
-    # As a result, we need to reconstruct the list of pose bones in the same order as the
-    # armature bones.
-    bone_names = [x.name for x in bones]
-
-    # Get a list of all the bone indices and instigator bones for the bone filter settings.
-    export_bone_names = get_export_bone_names(armature_object, options.bone_filter_mode, options.bone_collection_indices)
-    bone_indices = [bone_names.index(x) for x in export_bone_names]
-
-    # Make the bone lists contain only the bones that are going to be exported.
-    bones = [bones[bone_index] for bone_index in bone_indices]
-
-    # No bones are going to be exported.
-    if len(bones) == 0:
-        raise RuntimeError('No bones available for export')
+    psx_bone_create_result = create_psx_bones(
+        armature_objects=options.armature_objects,
+        export_space=options.export_space,
+        root_bone_name=options.root_bone_name,
+        forward_axis=options.forward_axis,
+        up_axis=options.up_axis,
+        scale=options.scale,
+        bone_filter_mode=options.bone_filter_mode,
+        bone_collection_indices=options.bone_collection_indices,
+    )
 
     # Build list of PSA bones.
-    for bone in bones:
-        psa_bone = Psa.Bone()
+    # Note that the PSA bones are just here to validate the hierarchy.
+    # The bind pose information is not used by the engine.
+    psa.bones = [psx_bone for psx_bone, _ in psx_bone_create_result.bones]
 
-        try:
-            psa_bone.name = bytes(bone.name, encoding='windows-1252')
-        except UnicodeEncodeError:
-            raise RuntimeError(f'Bone name "{bone.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
-
-        try:
-            parent_index = bones.index(bone.parent)
-            psa_bone.parent_index = parent_index
-            psa.bones[parent_index].children_count += 1
-        except ValueError:
-            psa_bone.parent_index = 0
-
-        if bone.parent is not None:
-            rotation = bone.matrix.to_quaternion().conjugated()
-            inverse_parent_rotation = bone.parent.matrix.to_quaternion().inverted()
-            parent_head = inverse_parent_rotation @ bone.parent.head
-            parent_tail = inverse_parent_rotation @ bone.parent.tail
-            location = (parent_tail - parent_head) + bone.head
-        else:
-            armature_local_matrix = armature_object.matrix_local
-            location = armature_local_matrix @ bone.head
-            bone_rotation = bone.matrix.to_quaternion().conjugated()
-            local_rotation = armature_local_matrix.to_3x3().to_quaternion().conjugated()
-            rotation = bone_rotation @ local_rotation
-            rotation.conjugate()
-
-        psa_bone.location.x = location.x
-        psa_bone.location.y = location.y
-        psa_bone.location.z = location.z
-
-        psa_bone.rotation.x = rotation.x
-        psa_bone.rotation.y = rotation.y
-        psa_bone.rotation.z = rotation.z
-        psa_bone.rotation.w = rotation.w
-
-        psa.bones.append(psa_bone)
+    # No bones are going to be exported.
+    if len(psa.bones) == 0:
+        raise RuntimeError('No bones available for export')
 
     # Add prefixes and suffices to the names of the export sequences and strip whitespace.
     for export_sequence in options.sequences:
         export_sequence.name = f'{options.sequence_name_prefix}{export_sequence.name}{options.sequence_name_suffix}'
         export_sequence.name = export_sequence.name.strip()
 
-    # Save the current action and frame so that we can restore the state once we are done.
+    # Save each armature object's current action and frame so that we can restore the state once we are done.
+    saved_armature_object_actions = {o: o.animation_data.action for o in options.armature_objects}
     saved_frame_current = context.scene.frame_current
-    saved_action = options.animation_data.action
 
     # Now build the PSA sequences.
     # We actually alter the timeline frame and simply record the resultant pose bone matrices.
@@ -142,17 +135,9 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
 
     context.window_manager.progress_begin(0, len(options.sequences))
 
+    coordinate_system_transform = get_coordinate_system_transform(options.forward_axis, options.up_axis)
+
     for export_sequence_index, export_sequence in enumerate(options.sequences):
-        # Look up the pose bones for the bones that are going to be exported.
-        pose_bones = [(bone_names.index(bone.name), bone) for bone in export_sequence.armature_object.pose.bones]
-        pose_bones.sort(key=lambda x: x[0])
-        pose_bones = [x[1] for x in pose_bones]
-        pose_bones = [pose_bones[bone_index] for bone_index in bone_indices]
-
-        # Link the action to the animation data and update view layer.
-        export_sequence.anim_data.action = export_sequence.nla_state.action
-        context.view_layer.update()
-
         frame_start = export_sequence.nla_state.frame_start
         frame_end = export_sequence.nla_state.frame_end
 
@@ -166,26 +151,33 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
         except ZeroDivisionError:
             frame_step = 0.0
 
-        sequence_duration = frame_count_raw / export_sequence.fps
-
         # If this is a reverse sequence, we need to reverse the frame step.
         if frame_start > frame_end:
             frame_step = -frame_step
 
+        sequence_duration = frame_count_raw / export_sequence.fps
+
         psa_sequence = Psa.Sequence()
         try:
             psa_sequence.name = bytes(export_sequence.name, encoding='windows-1252')
         except UnicodeEncodeError:
-            raise RuntimeError(f'Sequence name "{export_sequence.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
+            raise RuntimeError(
+                f'Sequence name "{export_sequence.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
         psa_sequence.frame_count = frame_count
         psa_sequence.frame_start_index = frame_start_index
         psa_sequence.fps = frame_count / sequence_duration
-        psa_sequence.bone_count = len(pose_bones)
+        psa_sequence.bone_count = len(psa.bones)
         psa_sequence.track_time = frame_count
         psa_sequence.key_reduction = 1.0
 
         frame = float(frame_start)
 
+        # Link the action to the animation data and update view layer.
+        for armature_object in options.armature_objects:
+            armature_object.animation_data.action = export_sequence.nla_state.action
+
+        context.view_layer.update()
+
         def add_key(location: Vector, rotation: Quaternion):
             key = Psa.Key()
             key.location.x = location.x
@@ -198,6 +190,38 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
             key.time = 1.0 / psa_sequence.fps
             psa.keys.append(key)
 
+        class PsaExportBone:
+            def __init__(self, pose_bone: Optional[PoseBone], armature_object: Optional[Object], scale: Vector):
+                self.pose_bone = pose_bone
+                self.armature_object = armature_object
+                self.scale = scale
+
+        armature_scales: Dict[Object, Vector] = {}
+
+        # Extract the scale from the world matrix of the evaluated armature object.
+        for armature_object in options.armature_objects:
+            evaluated_armature_object = armature_object.evaluated_get(context.evaluated_depsgraph_get())
+            _, _, scale = evaluated_armature_object.matrix_world.decompose()
+            scale *= options.scale
+            armature_scales[armature_object] = scale
+
+        # Create a list of export pose bones, in the same order as the bones as they appear in the armature.
+        # The object contains the pose bone, the armature object, and a pre-calculated scaling value to apply to the
+        # locations.
+        export_bones: List[PsaExportBone] = []
+
+        for psx_bone, armature_object in psx_bone_create_result.bones:
+            if armature_object is None:
+                export_bones.append(PsaExportBone(None, None, Vector((1.0, 1.0, 1.0))))
+                continue
+
+            pose_bone = armature_object.pose.bones[psx_bone.name.decode('windows-1252')]
+
+            export_bones.append(PsaExportBone(pose_bone, armature_object, armature_scales[armature_object]))
+
+        for export_bone in export_bones:
+            print(export_bone.pose_bone, export_bone.armature_object, export_bone.scale)
+
         match options.sampling_mode:
             case 'INTERPOLATED':
                 # Used as a store for the last frame's pose bone locations and rotations.
@@ -220,10 +244,15 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
                         else:
                             last_frame_bone_poses.clear()
                             context.scene.frame_set(frame=last_frame)
-                            for pose_bone in pose_bones:
-                                location, rotation = _get_pose_bone_location_and_rotation(pose_bone,
-                                                                                          export_sequence.armature_object,
-                                                                                          options)
+                            for export_bone in export_bones:
+                                location, rotation = _get_pose_bone_location_and_rotation(
+                                    export_bone.pose_bone,
+                                    export_bone.armature_object,
+                                    options.export_space,
+                                    export_bone.scale,
+                                    coordinate_system_transform=coordinate_system_transform,
+                                    has_false_root_bone=psx_bone_create_result.has_false_root_bone,
+                                )
                                 last_frame_bone_poses.append((location, rotation))
 
                         next_frame = None
@@ -231,20 +260,27 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
 
                     # If this is not a subframe, just use the last frame's bone poses.
                     if frame % 1.0 == 0:
-                        for i in range(len(pose_bones)):
+                        for i in range(len(export_bones)):
                             add_key(*last_frame_bone_poses[i])
                     else:
                         # Otherwise, this is a subframe, so we need to interpolate the pose between the next frame and the last frame.
                         if next_frame is None:
                             next_frame = last_frame + 1
                             context.scene.frame_set(frame=next_frame)
-                            for pose_bone in pose_bones:
-                                location, rotation = _get_pose_bone_location_and_rotation(pose_bone, export_sequence.armature_object, options)
+                            for export_bone in export_bones:
+                                location, rotation = _get_pose_bone_location_and_rotation(
+                                    pose_bone=export_bone.pose_bone,
+                                    armature_object=export_bone.armature_object,
+                                    export_space=options.export_space,
+                                    scale=export_bone.scale,
+                                    coordinate_system_transform=coordinate_system_transform,
+                                    has_false_root_bone=psx_bone_create_result.has_false_root_bone,
+                                )
                                 next_frame_bone_poses.append((location, rotation))
 
                         factor = frame % 1.0
 
-                        for i in range(len(pose_bones)):
+                        for i in range(len(export_bones)):
                             last_location, last_rotation = last_frame_bone_poses[i]
                             next_location, next_rotation = next_frame_bone_poses[i]
 
@@ -258,8 +294,15 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
                 for _ in range(frame_count):
                     context.scene.frame_set(frame=int(frame), subframe=frame % 1.0)
 
-                    for pose_bone in pose_bones:
-                        location, rotation = _get_pose_bone_location_and_rotation(pose_bone, export_sequence.armature_object, options)
+                    for export_bone in export_bones:
+                        location, rotation = _get_pose_bone_location_and_rotation(
+                            pose_bone=export_bone.pose_bone,
+                            armature_object=export_bone.armature_object,
+                            export_space=options.export_space,
+                            scale=export_bone.scale,
+                            coordinate_system_transform=coordinate_system_transform,
+                            has_false_root_bone=psx_bone_create_result.has_false_root_bone,
+                        )
                         add_key(location, rotation)
 
                     frame += frame_step
@@ -270,8 +313,10 @@ def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
 
         context.window_manager.progress_update(export_sequence_index)
 
-    # Restore the previous action & frame.
-    options.animation_data.action = saved_action
+    # Restore the previous actions & frame.
+    for armature_object, action in saved_armature_object_actions.items():
+        armature_object.animation_data.action = action
+
     context.scene.frame_set(saved_frame_current)
 
     context.window_manager.progress_end()

io_scene_psk_psa/psa/data.py

@@ -1,26 +1,15 @@
-import typing
 from collections import OrderedDict
-from typing import List
+from typing import List, OrderedDict as OrderedDictType
 
-from ..shared.data import *
-
-'''
-Note that keys are not stored within the Psa object.
-Use the PsaReader::get_sequence_keys to get the keys for a sequence.
-'''
+from ctypes import Structure, c_char, c_int32, c_float
+from ..shared.data import PsxBone, Quaternion, Vector3
 
 
 class Psa:
-    class Bone(Structure):
-        _fields_ = [
-            ('name', c_char * 64),
-            ('flags', c_int32),
-            ('children_count', c_int32),
-            ('parent_index', c_int32),
-            ('rotation', Quaternion),
-            ('location', Vector3),
-            ('padding', c_char * 16)
-        ]
+    """
+    Note that keys are not stored within the Psa object.
+    Use the `PsaReader.get_sequence_keys` to get the keys for a sequence.
+    """
 
     class Sequence(Structure):
         _fields_ = [
@@ -59,6 +48,6 @@ class Psa:
             return repr((self.location, self.rotation, self.time))
 
     def __init__(self):
-        self.bones: List[Psa.Bone] = []
-        self.sequences: typing.OrderedDict[str, Psa.Sequence] = OrderedDict()
+        self.bones: List[PsxBone] = []
+        self.sequences: OrderedDictType[str, Psa.Sequence] = OrderedDict()
         self.keys: List[Psa.Key] = []

io_scene_psk_psa/psa/export/operators.py

@@ -1,17 +1,21 @@
 from collections import Counter
-from typing import List, Iterable, Dict, Tuple, cast, Optional
+from typing import List, Iterable, Dict, Tuple, Optional
 
 import bpy
 from bpy.props import StringProperty
-from bpy.types import Context, Armature, Action, Object, AnimData, TimelineMarker
+from bpy.types import Context, Action, Object, AnimData, TimelineMarker, Operator
 from bpy_extras.io_utils import ExportHelper
-from bpy_types import Operator
 
-from .properties import PSA_PG_export, PSA_PG_export_action_list_item, filter_sequences, \
-    get_sequences_from_name_and_frame_range
+from .properties import (
+    PSA_PG_export,
+    PSA_PG_export_action_list_item,
+    filter_sequences,
+    get_sequences_from_name_and_frame_range,
+)
 from ..builder import build_psa, PsaBuildSequence, PsaBuildOptions
 from ..writer import write_psa
-from ...shared.helpers import populate_bone_collection_list, get_nla_strips_in_frame_range, SemanticVersion
+from ...shared.helpers import populate_bone_collection_list, get_nla_strips_in_frame_range
+from ...shared.semver import SemanticVersion
 from ...shared.ui import draw_bone_filter_mode
 
 
@@ -26,18 +30,26 @@ def get_sequences_propnames_from_source(sequence_source: str) -> Optional[Tuple[
         case 'ACTIVE_ACTION':
             return 'active_action_list', 'active_action_list_index'
         case _:
-            raise ValueError(f'Unhandled sequence source: {sequence_source}')
+            assert False, f'Invalid sequence source: {sequence_source}'
 
 
-def is_action_for_armature(armature: Armature, action: Action):
-    if len(action.fcurves) == 0:
+def is_action_for_object(obj: Object, action: Action):
+    if action is None or len(action.fcurves) == 0:
+        return False
+
+    if obj is None or obj.animation_data is None or obj.type != 'ARMATURE':
         return False
 
     version = SemanticVersion(bpy.app.version)
 
-    if version < SemanticVersion((4, 4, 0)):
+    def is_action_for_object_legacy(action: Action,  obj: Object):
+        """
+        This is the legacy behavior before slotted actions were introduced in Blender 4.4.
+        It would simply check if it had any f-curves that corresponded to any bones in the armature.
+        """
         import re
-        bone_names = set([x.name for x in armature.bones])
+        armature_data = obj.data
+        bone_names = set([x.name for x in armature_data.bones])
         for fcurve in action.fcurves:
             match = re.match(r'pose\.bones\[\"([^\"]+)\"](\[\"([^\"]+)\"])?', fcurve.data_path)
             if not match:
@@ -45,18 +57,15 @@ def is_action_for_armature(armature: Armature, action: Action):
             bone_name = match.group(1)
             if bone_name in bone_names:
                 return True
-    else:
-        # Look up the armature by ID and check if its data block pointer matches the armature.
-        for slot in filter(lambda x: x.id_root == 'OBJECT', action.slots):
-            # Lop off the 'OB' prefix from the identifier for the lookup.
-            object = bpy.data.objects.get(slot.identifier[2:], None)
-            if object and object.data == armature:
-                return True
 
-    return False
+    if version < SemanticVersion((4, 4, 0)):
+        return is_action_for_object_legacy(action, obj)
+
+    # If the object is a part of the slot's user list, then it is a valid action for the object.
+    return any(obj in slot.users() for slot in action.slots)
 
 
-def update_actions_and_timeline_markers(context: Context):
+def update_actions_and_timeline_markers(context: Context, armature_objects: Iterable[Object]):
     pg = getattr(context.scene, 'psa_export')
 
     # Clear actions and markers.
@@ -65,35 +74,35 @@ def update_actions_and_timeline_markers(context: Context):
     pg.active_action_list.clear()
 
     # Get animation data.
+    # TODO: Not sure how to handle this with multiple armatures.
     animation_data_object = get_animation_data_object(context)
     animation_data = animation_data_object.animation_data if animation_data_object else None
 
     if animation_data is None:
         return
 
-    active_armature = cast(Armature, context.active_object.data)
-
     # Populate actions list.
     for action in bpy.data.actions:
-        if not is_action_for_armature(active_armature, action):
+        if not any(map(lambda armature_object: is_action_for_object(armature_object, action), armature_objects)):
+            # This action is not applicable to any of the selected armatures.
             continue
 
-        if action.name != '' and not action.name.startswith('#'):
-            for (name, frame_start, frame_end) in get_sequences_from_action(action):
-                item = pg.action_list.add()
-                item.action = action
-                item.name = name
-                item.is_selected = False
-                item.is_pose_marker = False
-                item.frame_start = frame_start
-                item.frame_end = frame_end
+        for (name, frame_start, frame_end) in get_sequences_from_action(action):
+            item = pg.action_list.add()
+            item.action = action
+            item.name = name
+            item.is_selected = False
+            item.is_pose_marker = False
+            item.frame_start = frame_start
+            item.frame_end = frame_end
 
         # Pose markers are not guaranteed to be in frame-order, so make sure that they are.
         pose_markers = sorted(action.pose_markers, key=lambda x: x.frame)
         for pose_marker_index, pose_marker in enumerate(pose_markers):
             if pose_marker.name.strip() == '' or pose_marker.name.startswith('#'):
                 continue
-            for (name, frame_start, frame_end) in get_sequences_from_action_pose_markers(action, pose_markers, pose_marker, pose_marker_index):
+            sequences = get_sequences_from_action_pose_markers(action, pose_markers, pose_marker, pose_marker_index)
+            for (name, frame_start, frame_end) in sequences:
                 item = pg.action_list.add()
                 item.action = action
                 item.name = name
@@ -146,18 +155,22 @@ def get_sequence_fps(context: Context, fps_source: str, fps_custom: float, actio
             # Get the minimum value of action metadata FPS values.
             return min([action.psa_export.fps for action in actions])
         case _:
-            raise RuntimeError(f'Invalid FPS source "{fps_source}"')
+            assert False, f'Invalid FPS source: {fps_source}'
 
 
-def get_sequence_compression_ratio(compression_ratio_source: str, compression_ratio_custom: float, actions: Iterable[Action]) -> float:
+def get_sequence_compression_ratio(
+        compression_ratio_source: str, 
+        compression_ratio_custom: float, 
+        actions: Iterable[Action],
+        ) -> float:
     match compression_ratio_source:
         case 'ACTION_METADATA':
             # Get the minimum value of action metadata compression ratio values.
-            return min([action.psa_export.compression_ratio for action in actions])
+            return min(map(lambda action: action.psa_export.compression_ratio, actions))
         case 'CUSTOM':
             return compression_ratio_custom
         case _:
-            raise RuntimeError(f'Invalid compression ratio source "{compression_ratio_source}"')
+            assert False, f'Invalid compression ratio source: {compression_ratio_source}'
 
 
 def get_animation_data_object(context: Context) -> Object:
@@ -166,7 +179,7 @@ def get_animation_data_object(context: Context) -> Object:
     active_object = context.view_layer.objects.active
 
     if active_object.type != 'ARMATURE':
-        raise RuntimeError('Selected object must be an Armature')
+        raise RuntimeError('Active object must be an Armature')
 
     if pg.sequence_source != 'ACTIONS' and pg.should_override_animation_data:
         animation_data_object = pg.animation_data_override
@@ -176,7 +189,11 @@ def get_animation_data_object(context: Context) -> Object:
     return animation_data_object
 
 
-def get_timeline_marker_sequence_frame_ranges(animation_data: AnimData, context: Context, marker_names: List[str]) -> Dict:
+def get_timeline_marker_sequence_frame_ranges(
+        animation_data: AnimData, 
+        context: Context, 
+        marker_names: List[str],
+        ) -> Dict:
     # Timeline markers need to be sorted so that we can determine the sequence start and end positions.
     sequence_frame_ranges = dict()
     sorted_timeline_markers = list(sorted(context.scene.timeline_markers, key=lambda x: x.frame))
@@ -217,13 +234,29 @@ def get_timeline_marker_sequence_frame_ranges(animation_data: AnimData, context:
     return sequence_frame_ranges
 
 
-def get_sequences_from_action(action: Action) -> List[Tuple[str, int, int]]:
+def get_sequences_from_action(action: Action):
+    if action.name == '' or action.name.startswith('#'):
+        return
+
     frame_start = int(action.frame_range[0])
-    frame_end = int(action.frame_range[1])
-    return get_sequences_from_name_and_frame_range(action.name, frame_start, frame_end)
+    action_name = action.name
+
+    if action_name.startswith('!'):
+        # If the pose marker name starts with an exclamation mark, only export the first frame.
+        frame_end = frame_start
+        action_name = action_name[1:]
+    else:
+        frame_end = int(action.frame_range[1])
+
+    yield from get_sequences_from_name_and_frame_range(action_name, frame_start, frame_end)
 
 
-def get_sequences_from_action_pose_markers(action: Action, pose_markers: List[TimelineMarker], pose_marker: TimelineMarker, pose_marker_index: int) -> List[Tuple[str, int, int]]:
+def get_sequences_from_action_pose_markers(
+        action: Action, 
+        pose_markers: List[TimelineMarker], 
+        pose_marker: TimelineMarker, 
+        pose_marker_index: int,
+        ):
     frame_start = pose_marker.frame
     sequence_name = pose_marker.name
     if pose_marker.name.startswith('!'):
@@ -234,7 +267,7 @@ def get_sequences_from_action_pose_markers(action: Action, pose_markers: List[Ti
         frame_end = pose_markers[pose_marker_index + 1].frame
     else:
         frame_end = int(action.frame_range[1])
-    return get_sequences_from_name_and_frame_range(sequence_name, frame_start, frame_end)
+    yield from get_sequences_from_name_and_frame_range(sequence_name, frame_start, frame_end)
 
 
 def get_visible_sequences(pg: PSA_PG_export, sequences) -> List[PSA_PG_export_action_list_item]:
@@ -246,7 +279,7 @@ def get_visible_sequences(pg: PSA_PG_export, sequences) -> List[PSA_PG_export_ac
 
 
 class PSA_OT_export(Operator, ExportHelper):
-    bl_idname = 'psa_export.operator'
+    bl_idname = 'psa.export'
     bl_label = 'Export'
     bl_options = {'INTERNAL', 'UNDO'}
     bl_description = 'Export actions to PSA'
@@ -260,7 +293,7 @@ class PSA_OT_export(Operator, ExportHelper):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.armature_object = None
+        self.armature_objects: List[Object] = []
 
     @classmethod
     def poll(cls, context):
@@ -362,19 +395,31 @@ class PSA_OT_export(Operator, ExportHelper):
                 row.operator(PSA_OT_export_bone_collections_select_all.bl_idname, text='All', icon='CHECKBOX_HLT')
                 row.operator(PSA_OT_export_bone_collections_deselect_all.bl_idname, text='None', icon='CHECKBOX_DEHLT')
                 rows = max(3, min(len(pg.bone_collection_list), 10))
-                bones_panel.template_list('PSX_UL_bone_collection_list', '', pg, 'bone_collection_list', pg, 'bone_collection_list_index',
-                                     rows=rows)
+                bones_panel.template_list(
+                    'PSX_UL_bone_collection_list', '', pg, 'bone_collection_list', pg, 'bone_collection_list_index',
+                    rows=rows
+                    )
+
+            bones_advanced_header, bones_advanced_panel = layout.panel('Advanced', default_closed=False)
+            bones_advanced_header.label(text='Advanced')
+            if bones_advanced_panel:
+                flow = bones_advanced_panel.grid_flow()
+                flow.use_property_split = True
+                flow.use_property_decorate = False
+                flow.prop(pg, 'root_bone_name', text='Root Bone Name')
 
         # TRANSFORM
         transform_header, transform_panel = layout.panel('Advanced', default_closed=False)
         transform_header.label(text='Transform')
 
         if transform_panel:
-            flow = transform_panel.grid_flow()
+            flow = transform_panel.grid_flow(row_major=True)
             flow.use_property_split = True
             flow.use_property_decorate = False
-            flow.prop(pg, 'root_motion', text='Root Motion')
-            flow.prop(pg, 'scale', text='Scale')
+            flow.prop(pg, 'export_space')
+            flow.prop(pg, 'scale')
+            flow.prop(pg, 'forward_axis')
+            flow.prop(pg, 'up_axis')
 
     @classmethod
     def _check_context(cls, context):
@@ -384,18 +429,10 @@ class PSA_OT_export(Operator, ExportHelper):
         if context.view_layer.objects.active.type != 'ARMATURE':
             raise RuntimeError('The active object must be an armature')
 
-        # If we have multiple armatures selected, make sure that they all use the same underlying armature data.
-        armature_objects = [obj for obj in context.selected_objects if obj.type == 'ARMATURE']
-
-        for obj in armature_objects:
-            if obj.data != context.view_layer.objects.active.data:
-                raise RuntimeError(f'All selected armatures must use the same armature data block.\n\n'
-                                   f'\The armature data block for "{obj.name}\" (\'{obj.data.name}\') does not match '
-                                   f'the active armature data block (\'{context.view_layer.objects.active.name}\')')
-
         if context.scene.is_nla_tweakmode:
             raise RuntimeError('Cannot export PSA while in NLA tweak mode')
 
+
     def invoke(self, context, _event):
         try:
             self._check_context(context)
@@ -404,16 +441,16 @@ class PSA_OT_export(Operator, ExportHelper):
 
         pg: PSA_PG_export = getattr(context.scene, 'psa_export')
 
-        self.armature_object = context.view_layer.objects.active
+        self.armature_objects = [x for x in context.view_layer.objects.selected if x.type == 'ARMATURE']
 
-        if self.armature_object.animation_data is None:
+        for armature_object in self.armature_objects:
             # This is required otherwise the action list will be empty if the armature has never had its animation
             # data created before (i.e. if no action was ever assigned to it).
-            self.armature_object.animation_data_create()
+            if armature_object.animation_data is None:
+                armature_object.animation_data_create()
 
-        update_actions_and_timeline_markers(context)
-
-        populate_bone_collection_list(self.armature_object, pg.bone_collection_list)
+        update_actions_and_timeline_markers(context, self.armature_objects)
+        populate_bone_collection_list(self.armature_objects, pg.bone_collection_list)
 
         context.window_manager.fileselect_add(self)
 
@@ -425,9 +462,11 @@ class PSA_OT_export(Operator, ExportHelper):
         # Ensure that we actually have items that we are going to be exporting.
         if pg.sequence_source == 'ACTIONS' and len(pg.action_list) == 0:
             raise RuntimeError('No actions were selected for export')
-        elif pg.sequence_source == 'TIMELINE_MARKERS' and len(pg.marker_list) == 0:
+
+        if pg.sequence_source == 'TIMELINE_MARKERS' and len(pg.marker_list) == 0:
             raise RuntimeError('No timeline markers were selected for export')
-        elif pg.sequence_source == 'NLA_TRACK_STRIPS' and len(pg.nla_strip_list) == 0:
+
+        if pg.sequence_source == 'NLA_TRACK_STRIPS' and len(pg.nla_strip_list) == 0:
             raise RuntimeError('No NLA track strips were selected for export')
 
         # Populate the export sequence list.
@@ -439,8 +478,6 @@ class PSA_OT_export(Operator, ExportHelper):
 
         export_sequences: List[PsaBuildSequence] = []
 
-        selected_armature_objects = [obj for obj in context.selected_objects if obj.type == 'ARMATURE']
-
         match pg.sequence_source:
             case 'ACTIONS':
                 for action_item in filter(lambda x: x.is_selected, pg.action_list):
@@ -489,18 +526,26 @@ class PSA_OT_export(Operator, ExportHelper):
                     export_sequence.key_quota = action.psa_export.key_quota
                     export_sequences.append(export_sequence)
             case _:
-                raise ValueError(f'Unhandled sequence source: {pg.sequence_source}')
+                assert False, f'Invalid sequence source: {pg.sequence_source}'
+
+        if len(export_sequences) == 0:
+            self.report({'ERROR'}, 'No sequences were selected for export')
+            return {'CANCELLED'}
 
         options = PsaBuildOptions()
+        options.armature_objects = self.armature_objects
         options.animation_data = animation_data
         options.sequences = export_sequences
         options.bone_filter_mode = pg.bone_filter_mode
-        options.bone_collection_indices = [x.index for x in pg.bone_collection_list if x.is_selected]
+        options.bone_collection_indices = [(x.armature_object_name, x.index) for x in pg.bone_collection_list if x.is_selected]
         options.sequence_name_prefix = pg.sequence_name_prefix
         options.sequence_name_suffix = pg.sequence_name_suffix
-        options.root_motion = pg.root_motion
         options.scale = pg.scale
         options.sampling_mode = pg.sampling_mode
+        options.export_space = pg.export_space
+        options.forward_axis = pg.forward_axis
+        options.up_axis = pg.up_axis
+        options.root_bone_name = pg.root_bone_name
 
         try:
             psa = build_psa(context, options)
@@ -515,7 +560,7 @@ class PSA_OT_export(Operator, ExportHelper):
 
 
 class PSA_OT_export_actions_select_all(Operator):
-    bl_idname = 'psa_export.sequences_select_all'
+    bl_idname = 'psa.export_actions_select_all'
     bl_label = 'Select All'
     bl_description = 'Select all visible sequences'
     bl_options = {'INTERNAL'}
@@ -533,7 +578,7 @@ class PSA_OT_export_actions_select_all(Operator):
             case 'ACTIVE_ACTION':
                 return pg.active_action_list
             case _:
-                return None
+                assert False, f'Invalid sequence source: {pg.sequence_source}'
 
     @classmethod
     def poll(cls, context):
@@ -552,7 +597,7 @@ class PSA_OT_export_actions_select_all(Operator):
 
 
 class PSA_OT_export_actions_deselect_all(Operator):
-    bl_idname = 'psa_export.sequences_deselect_all'
+    bl_idname = 'psa.export_sequences_deselect_all'
     bl_label = 'Deselect All'
     bl_description = 'Deselect all visible sequences'
     bl_options = {'INTERNAL'}
@@ -587,7 +632,7 @@ class PSA_OT_export_actions_deselect_all(Operator):
 
 
 class PSA_OT_export_bone_collections_select_all(Operator):
-    bl_idname = 'psa_export.bone_collections_select_all'
+    bl_idname = 'psa.export_bone_collections_select_all'
     bl_label = 'Select All'
     bl_description = 'Select all bone collections'
     bl_options = {'INTERNAL'}
@@ -607,7 +652,7 @@ class PSA_OT_export_bone_collections_select_all(Operator):
 
 
 class PSA_OT_export_bone_collections_deselect_all(Operator):
-    bl_idname = 'psa_export.bone_collections_deselect_all'
+    bl_idname = 'psa.export_bone_collections_deselect_all'
     bl_label = 'Deselect All'
     bl_description = 'Deselect all bone collections'
     bl_options = {'INTERNAL'}

io_scene_psk_psa/psa/export/properties.py

@@ -1,23 +1,24 @@
 import re
 import sys
 from fnmatch import fnmatch
-from typing import List, Optional, Tuple
-
-from bpy.props import BoolProperty, PointerProperty, EnumProperty, FloatProperty, CollectionProperty, IntProperty, \
-    StringProperty
+from typing import List, Optional
+from bpy.props import (
+    BoolProperty,
+    PointerProperty,
+    EnumProperty,
+    FloatProperty,
+    CollectionProperty,
+    IntProperty,
+    StringProperty,
+)
 from bpy.types import PropertyGroup, Object, Action, AnimData, Context
-
-from ...shared.data import bone_filter_mode_items
-from ...shared.types import PSX_PG_bone_collection_list_item
+from ...shared.types import ForwardUpAxisMixin, ExportSpaceMixin, PsxBoneExportMixin
 
 
 def psa_export_property_group_animation_data_override_poll(_context, obj):
     return obj.animation_data is not None
 
 
-empty_set = set()
-
-
 class PSA_PG_export_action_list_item(PropertyGroup):
     action: PointerProperty(type=Action)
     name: StringProperty()
@@ -52,18 +53,16 @@ class PSA_PG_export_nla_strip_list_item(PropertyGroup):
     is_selected: BoolProperty(default=True)
 
 
-def get_sequences_from_name_and_frame_range(name: str, frame_start: int, frame_end: int) -> List[Tuple[str, int, int]]:
+def get_sequences_from_name_and_frame_range(name: str, frame_start: int, frame_end: int):
     reversed_pattern = r'(.+)/(.+)'
     reversed_match = re.match(reversed_pattern, name)
     if reversed_match:
         forward_name = reversed_match.group(1)
         backwards_name = reversed_match.group(2)
-        return [
-            (forward_name, frame_start, frame_end),
-            (backwards_name, frame_end, frame_start)
-        ]
+        yield forward_name, frame_start, frame_end
+        yield backwards_name, frame_end, frame_start
     else:
-        return [(name, frame_start, frame_end)]
+        yield name, frame_start, frame_end
 
 
 def nla_track_update_cb(self: 'PSA_PG_export', context: Context) -> None:
@@ -104,18 +103,10 @@ def animation_data_override_update_cb(self: 'PSA_PG_export', context: Context):
     self.nla_track = ''
 
 
-class PSA_PG_export(PropertyGroup):
-    root_motion: BoolProperty(
-        name='Root Motion',
-        options=empty_set,
-        default=False,
-        description='When enabled, the root bone will be transformed as it appears in the scene.\n\n'
-                    'You might want to disable this if you are exporting an animation for an armature that is '
-                    'attached to another object, such as a weapon or a shield',
-    )
+class PSA_PG_export(PropertyGroup, ForwardUpAxisMixin, ExportSpaceMixin, PsxBoneExportMixin):
     should_override_animation_data: BoolProperty(
         name='Override Animation Data',
-        options=empty_set,
+        options=set(),
         default=False,
         description='Use the animation data from a different object instead of the selected object',
         update=animation_data_override_update_cb,
@@ -127,7 +118,7 @@ class PSA_PG_export(PropertyGroup):
     )
     sequence_source: EnumProperty(
         name='Source',
-        options=empty_set,
+        options=set(),
         description='',
         items=(
             ('ACTIONS', 'Actions', 'Sequences will be exported using actions', 'ACTION', 0),
@@ -138,7 +129,7 @@ class PSA_PG_export(PropertyGroup):
     )
     nla_track: StringProperty(
         name='NLA Track',
-        options=empty_set,
+        options=set(),
         description='',
         search=nla_track_search_cb,
         update=nla_track_update_cb
@@ -146,7 +137,7 @@ class PSA_PG_export(PropertyGroup):
     nla_track_index: IntProperty(name='NLA Track Index', default=-1)
     fps_source: EnumProperty(
         name='FPS Source',
-        options=empty_set,
+        options=set(),
         description='',
         items=(
             ('SCENE', 'Scene', '', 'SCENE_DATA', 0),
@@ -154,11 +145,11 @@ class PSA_PG_export(PropertyGroup):
             ('CUSTOM', 'Custom', '', 2)
         )
     )
-    fps_custom: FloatProperty(default=30.0, min=sys.float_info.epsilon, soft_min=1.0, options=empty_set, step=100,
+    fps_custom: FloatProperty(default=30.0, min=sys.float_info.epsilon, soft_min=1.0, options=set(), step=100,
                               soft_max=60.0)
     compression_ratio_source: EnumProperty(
         name='Compression Ratio Source',
-        options=empty_set,
+        options=set(),
         description='',
         items=(
             ('ACTION_METADATA', 'Action Metadata', 'The compression ratio will be determined by action\'s Compression Ratio property found in the PSA Export panel.\n\nIf the Sequence Source is Timeline Markers, the lowest value of all contributing actions will be used', 'ACTION', 1),
@@ -174,16 +165,8 @@ class PSA_PG_export(PropertyGroup):
     nla_strip_list_index: IntProperty(default=0)
     active_action_list: CollectionProperty(type=PSA_PG_export_active_action_list_item)
     active_action_list_index: IntProperty(default=0)
-    bone_filter_mode: EnumProperty(
-        name='Bone Filter',
-        options=empty_set,
-        description='',
-        items=bone_filter_mode_items,
-    )
-    bone_collection_list: CollectionProperty(type=PSX_PG_bone_collection_list_item)
-    bone_collection_list_index: IntProperty(default=0, name='', description='')
-    sequence_name_prefix: StringProperty(name='Prefix', options=empty_set)
-    sequence_name_suffix: StringProperty(name='Suffix', options=empty_set)
+    sequence_name_prefix: StringProperty(name='Prefix', options=set())
+    sequence_name_suffix: StringProperty(name='Suffix', options=set())
     sequence_filter_name: StringProperty(
         default='',
         name='Filter by Name',
@@ -192,21 +175,21 @@ class PSA_PG_export(PropertyGroup):
     sequence_use_filter_invert: BoolProperty(
         default=False,
         name='Invert',
-        options=empty_set,
+        options=set(),
         description='Invert filtering (show hidden items, and vice versa)')
     sequence_filter_asset: BoolProperty(
         default=False,
         name='Show assets',
-        options=empty_set,
+        options=set(),
         description='Show actions that belong to an asset library')
     sequence_filter_pose_marker: BoolProperty(
         default=True,
         name='Show pose markers',
-        options=empty_set)
-    sequence_use_filter_sort_reverse: BoolProperty(default=True, options=empty_set)
+        options=set())
+    sequence_use_filter_sort_reverse: BoolProperty(default=True, options=set())
     sequence_filter_reversed: BoolProperty(
         default=True,
-        options=empty_set,
+        options=set(),
         name='Show Reversed',
         description='Show reversed sequences'
     )
@@ -219,7 +202,7 @@ class PSA_PG_export(PropertyGroup):
     )
     sampling_mode: EnumProperty(
         name='Sampling Mode',
-        options=empty_set,
+        options=set(),
         description='The method by which frames are sampled',
         items=(
             ('INTERPOLATED', 'Interpolated', 'Sampling is performed by interpolating the evaluated bone poses from the adjacent whole frames.', 'INTERPOLATED', 0),

io_scene_psk_psa/psa/export/ui.py

@@ -1,4 +1,4 @@
-import typing
+from typing import cast as typing_cast
 
 from bpy.types import UIList
 
@@ -14,7 +14,7 @@ class PSA_UL_export_sequences(UIList):
         self.use_filter_show = True
 
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
-        item = typing.cast(PSA_PG_export_action_list_item, item)
+        item = typing_cast(PSA_PG_export_action_list_item, item)
 
         is_pose_marker = hasattr(item, 'is_pose_marker') and item.is_pose_marker
         layout.prop(item, 'is_selected', icon_only=True, text=item.name)
@@ -23,14 +23,14 @@ class PSA_UL_export_sequences(UIList):
 
         row = layout.row(align=True)
         row.alignment = 'RIGHT'
-        if item.frame_end < item.frame_start:
-            row.label(text='', icon='FRAME_PREV')
-        if is_pose_marker:
-            row.label(text=item.action.name, icon='PMARKER')
+
+        row.label(text=str(abs(item.frame_end - item.frame_start) + 1), icon='FRAME_PREV' if item.frame_end < item.frame_start else 'KEYFRAME')
 
         if hasattr(item, 'armature_object') and item.armature_object is not None:
             row.label(text=item.armature_object.name, icon='ARMATURE_DATA')
 
+        # row.label(text=item.action.name, icon='PMARKER' if is_pose_marker else 'ACTION_DATA')
+
     def draw_filter(self, context, layout):
         pg = getattr(context.scene, 'psa_export')
         row = layout.row()

io_scene_psk_psa/psa/import_/operators.py

@@ -1,19 +1,27 @@
 import os
 from pathlib import Path
-from typing import List
+from typing import Iterable
 
-from bpy.props import StringProperty, CollectionProperty
-from bpy.types import Operator, Event, Context, FileHandler, OperatorFileListElement, Object
+from bpy.props import CollectionProperty, StringProperty
+from bpy.types import Context, Event, FileHandler, Object, Operator, OperatorFileListElement
 from bpy_extras.io_utils import ImportHelper
 
-from .properties import get_visible_sequences
+from .properties import PsaImportMixin, get_visible_sequences
 from ..config import read_psa_config
-from ..importer import import_psa, PsaImportOptions
+from ..importer import PsaImportOptions, import_psa
 from ..reader import PsaReader
 
 
-class PSA_OT_import_sequences_from_text(Operator):
-    bl_idname = 'psa_import.sequences_select_from_text'
+def psa_import_poll(cls, context: Context):
+    active_object = context.view_layer.objects.active
+    if active_object is None or active_object.type != 'ARMATURE':
+        cls.poll_message_set('The active object must be an armature')
+        return False
+    return True
+
+
+class PSA_OT_import_sequences_select_from_text(Operator):
+    bl_idname = 'psa.import_sequences_select_from_text'
     bl_label = 'Select By Text List'
     bl_description = 'Select sequences by name from text list'
     bl_options = {'INTERNAL', 'UNDO'}
@@ -49,7 +57,7 @@ class PSA_OT_import_sequences_from_text(Operator):
 
 
 class PSA_OT_import_sequences_select_all(Operator):
-    bl_idname = 'psa_import.sequences_select_all'
+    bl_idname = 'psa.import_sequences_select_all'
     bl_label = 'All'
     bl_description = 'Select all sequences'
     bl_options = {'INTERNAL'}
@@ -70,7 +78,7 @@ class PSA_OT_import_sequences_select_all(Operator):
 
 
 class PSA_OT_import_sequences_deselect_all(Operator):
-    bl_idname = 'psa_import.sequences_deselect_all'
+    bl_idname = 'psa.import_sequences_deselect_all'
     bl_label = 'None'
     bl_description = 'Deselect all visible sequences'
     bl_options = {'INTERNAL'}
@@ -113,40 +121,42 @@ def on_psa_file_path_updated(cls, context):
     load_psa_file(context, cls.filepath)
 
 
-class PSA_OT_import_multiple(Operator):
-    bl_idname = 'psa_import.import_multiple'
+class PSA_OT_import_drag_and_drop(Operator, PsaImportMixin):
+    bl_idname = 'psa.import_drag_and_drop'
     bl_label = 'Import PSA'
     bl_description = 'Import multiple PSA files'
-    bl_options = {'INTERNAL', 'UNDO'}
+    bl_options = {'INTERNAL', 'UNDO', 'PRESET'}
 
     directory: StringProperty(subtype='FILE_PATH', options={'SKIP_SAVE', 'HIDDEN'})
     files: CollectionProperty(type=OperatorFileListElement, options={'SKIP_SAVE', 'HIDDEN'})
 
-
     def execute(self, context):
-        pg = getattr(context.scene, 'psa_import')
         warnings = []
+        sequences_count = 0
 
         for file in self.files:
-            psa_path = os.path.join(self.directory, file.name)
+            psa_path = str(os.path.join(self.directory, file.name))
             psa_reader = PsaReader(psa_path)
             sequence_names = list(psa_reader.sequences.keys())
+            options = psa_import_options_from_property_group(self, sequence_names)
 
-            result = _import_psa(context, pg, psa_path, sequence_names, context.view_layer.objects.active)
-            result.warnings.extend(warnings)
+            sequences_count += len(sequence_names)
 
-        if len(result.warnings) > 0:
-            message = f'Imported {len(sequence_names)} action(s) with {len(result.warnings)} warning(s)\n'
+            result = _import_psa(context, options, psa_path, context.view_layer.objects.active)
+            warnings.extend(result.warnings)
+
+        if len(warnings) > 0:
+            message = f'Imported {sequences_count} action(s) from {len(self.files)} file(s) with {len(warnings)} warning(s)\n'
             self.report({'INFO'}, message)
-            for warning in result.warnings:
+            for warning in warnings:
                 self.report({'WARNING'}, warning)
 
-        self.report({'INFO'}, f'Imported {len(sequence_names)} action(s)')
+        self.report({'INFO'}, f'Imported {sequences_count} action(s) from {len(self.files)} file(s)')
 
         return {'FINISHED'}
 
     def invoke(self, context: Context, event):
-        # Make sure the selected object is an armature.
+        # Make sure the selected object is an obj.
         active_object = context.view_layer.objects.active
         if active_object is None or active_object.type != 'ARMATURE':
             self.report({'ERROR_INVALID_CONTEXT'}, 'The active object must be an armature')
@@ -158,18 +168,12 @@ class PSA_OT_import_multiple(Operator):
 
     def draw(self, context):
         layout = self.layout
-        pg = getattr(context.scene, 'psa_import')
-        draw_psa_import_options_no_panels(layout, pg)
+        draw_psa_import_options_no_panels(layout, self)
 
 
-def _import_psa(context,
-                pg,
-                filepath: str,
-                sequence_names: List[str],
-                armature_object: Object
-                ):
+def psa_import_options_from_property_group(pg: PsaImportMixin, sequence_names: Iterable[str]) -> PsaImportOptions:
     options = PsaImportOptions()
-    options.sequence_names = sequence_names
+    options.sequence_names = list(sequence_names)
     options.should_use_fake_user = pg.should_use_fake_user
     options.should_stash = pg.should_stash
     options.action_name_prefix = pg.action_name_prefix if pg.should_use_action_name_prefix else ''
@@ -181,7 +185,14 @@ def _import_psa(context,
     options.fps_source = pg.fps_source
     options.fps_custom = pg.fps_custom
     options.translation_scale = pg.translation_scale
+    return options
 
+
+def _import_psa(context,
+                options: PsaImportOptions,
+                filepath: str,
+                armature_object: Object
+                ):
     warnings = []
 
     if options.should_use_config_file:
@@ -189,7 +200,7 @@ def _import_psa(context,
         config_path = Path(filepath).with_suffix('.config')
         if config_path.exists():
             try:
-                options.psa_config = read_psa_config(sequence_names, str(config_path))
+                options.psa_config = read_psa_config(options.sequence_names, str(config_path))
             except Exception as e:
                 warnings.append(f'Failed to read PSA config file: {e}')
 
@@ -201,8 +212,62 @@ def _import_psa(context,
     return result
 
 
-class PSA_OT_import(Operator, ImportHelper):
-    bl_idname = 'psa_import.import'
+class PSA_OT_import_all(Operator, PsaImportMixin):
+    bl_idname = 'psa.import_all'
+    bl_label = 'Import PSA'
+    bl_description = 'Import all sequences from the selected PSA file'
+    bl_options = {'INTERNAL', 'UNDO'}
+
+    filepath: StringProperty(
+        name='File Path',
+        description='File path used for importing the PSA file',
+        maxlen=1024,
+        default='',
+        update=on_psa_file_path_updated)
+
+    @classmethod
+    def poll(cls, context):
+        return psa_import_poll(cls, context)
+
+    def execute(self, context):
+        sequence_names = []
+        with PsaReader(self.filepath) as psa_reader:
+            sequence_names.extend(psa_reader.sequences.keys())
+
+        options = PsaImportOptions(
+            action_name_prefix=self.action_name_prefix,
+            bone_mapping_mode=self.bone_mapping_mode,
+            fps_custom=self.fps_custom,
+            fps_source=self.fps_source,
+            sequence_names=sequence_names,
+            should_convert_to_samples=self.should_convert_to_samples,
+            should_overwrite=self.should_overwrite,
+            should_stash=self.should_stash,
+            should_use_config_file=self.should_use_config_file,
+            should_use_fake_user=self.should_use_fake_user,
+            should_write_keyframes=self.should_write_keyframes,
+            should_write_metadata=self.should_write_metadata,
+            translation_scale=self.translation_scale
+        )
+
+        result = _import_psa(context, options, self.filepath, context.view_layer.objects.active)
+
+        if len(result.warnings) > 0:
+            message = f'Imported {len(options.sequence_names)} action(s) with {len(result.warnings)} warning(s)\n'
+            self.report({'WARNING'}, message)
+            for warning in result.warnings:
+                self.report({'WARNING'}, warning)
+        else:
+            self.report({'INFO'}, f'Imported {len(options.sequence_names)} action(s)')
+
+        return {'FINISHED'}
+
+    def draw(self, context: Context):
+        draw_psa_import_options_no_panels(self.layout, self)
+
+
+class PSA_OT_import(Operator, ImportHelper, PsaImportMixin):
+    bl_idname = 'psa.import_file'
     bl_label = 'Import'
     bl_description = 'Import the selected animations into the scene as actions'
     bl_options = {'INTERNAL', 'UNDO'}
@@ -218,29 +283,25 @@ class PSA_OT_import(Operator, ImportHelper):
 
     @classmethod
     def poll(cls, context):
-        active_object = context.view_layer.objects.active
-        if active_object is None or active_object.type != 'ARMATURE':
-            cls.poll_message_set('The active object must be an armature')
-            return False
-        return True
+        return psa_import_poll(cls, context)
 
     def execute(self, context):
         pg = getattr(context.scene, 'psa_import')
-        sequence_names = [x.action_name for x in pg.sequence_list if x.is_selected]
+        options = psa_import_options_from_property_group(self, [x.action_name for x in pg.sequence_list if x.is_selected])
 
-        if len(sequence_names) == 0:
+        if len(options.sequence_names) == 0:
             self.report({'ERROR_INVALID_CONTEXT'}, 'No sequences selected')
             return {'CANCELLED'}
 
-        result = _import_psa(context, pg, self.filepath, sequence_names, context.view_layer.objects.active)
+        result = _import_psa(context, options, self.filepath, context.view_layer.objects.active)
 
         if len(result.warnings) > 0:
-            message = f'Imported {len(sequence_names)} action(s) with {len(result.warnings)} warning(s)\n'
+            message = f'Imported {len(options.sequence_names)} action(s) with {len(result.warnings)} warning(s)\n'
             self.report({'WARNING'}, message)
             for warning in result.warnings:
                 self.report({'WARNING'}, warning)
         else:
-            self.report({'INFO'}, f'Imported {len(sequence_names)} action(s)')
+            self.report({'INFO'}, f'Imported {len(options.sequence_names)} action(s)')
 
         return {'FINISHED'}
 
@@ -271,7 +332,7 @@ class PSA_OT_import(Operator, ImportHelper):
 
                 row2 = col.row(align=True)
                 row2.label(text='Select')
-                row2.operator(PSA_OT_import_sequences_from_text.bl_idname, text='', icon='TEXT')
+                row2.operator(PSA_OT_import_sequences_select_from_text.bl_idname, text='', icon='TEXT')
                 row2.operator(PSA_OT_import_sequences_select_all.bl_idname, text='All', icon='CHECKBOX_HLT')
                 row2.operator(PSA_OT_import_sequences_deselect_all.bl_idname, text='None', icon='CHECKBOX_DEHLT')
 
@@ -281,13 +342,13 @@ class PSA_OT_import(Operator, ImportHelper):
             col = sequences_panel.column(heading='')
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'fps_source')
-            if pg.fps_source == 'CUSTOM':
-                col.prop(pg, 'fps_custom')
-            col.prop(pg, 'should_overwrite')
-            col.prop(pg, 'should_use_action_name_prefix')
-            if pg.should_use_action_name_prefix:
-                col.prop(pg, 'action_name_prefix')
+            col.prop(self, 'fps_source')
+            if self.fps_source == 'CUSTOM':
+                col.prop(self, 'fps_custom')
+            col.prop(self, 'should_overwrite')
+            col.prop(self, 'should_use_action_name_prefix')
+            if self.should_use_action_name_prefix:
+                col.prop(self, 'action_name_prefix')
 
         data_header, data_panel = layout.panel('data_panel_id', default_closed=False)
         data_header.label(text='Data')
@@ -296,14 +357,14 @@ class PSA_OT_import(Operator, ImportHelper):
             col = data_panel.column(heading='Write')
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'should_write_keyframes')
-            col.prop(pg, 'should_write_metadata')
+            col.prop(self, 'should_write_keyframes')
+            col.prop(self, 'should_write_metadata')
 
-            if pg.should_write_keyframes:
+            if self.should_write_keyframes:
                 col = col.column(heading='Keyframes')
                 col.use_property_split = True
                 col.use_property_decorate = False
-                col.prop(pg, 'should_convert_to_samples')
+                col.prop(self, 'should_convert_to_samples')
 
         advanced_header, advanced_panel = layout.panel('advanced_panel_id', default_closed=True)
         advanced_header.label(text='Advanced')
@@ -312,22 +373,22 @@ class PSA_OT_import(Operator, ImportHelper):
             col = advanced_panel.column()
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'bone_mapping_mode')
+            col.prop(self, 'bone_mapping_mode')
 
             col = advanced_panel.column()
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'translation_scale', text='Translation Scale')
+            col.prop(self, 'translation_scale', text='Translation Scale')
 
             col = advanced_panel.column(heading='Options')
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'should_use_fake_user')
-            col.prop(pg, 'should_stash')
-            col.prop(pg, 'should_use_config_file')
+            col.prop(self, 'should_use_fake_user')
+            col.prop(self, 'should_stash')
+            col.prop(self, 'should_use_config_file')
 
 
-def draw_psa_import_options_no_panels(layout, pg):
+def draw_psa_import_options_no_panels(layout, pg: PsaImportMixin):
     col = layout.column(heading='Sequences')
     col.use_property_split = True
     col.use_property_decorate = False
@@ -365,11 +426,11 @@ def draw_psa_import_options_no_panels(layout, pg):
     col.prop(pg, 'should_use_config_file')
 
 
-class PSA_FH_import(FileHandler):
+class PSA_FH_import(FileHandler):  # TODO: rename and add handling for PSA export.
     bl_idname = 'PSA_FH_import'
     bl_label = 'File handler for Unreal PSA import'
-    bl_import_operator = 'psa_import.import_multiple'
-    bl_export_operator = 'psa_export.export'
+    bl_import_operator = PSA_OT_import_drag_and_drop.bl_idname
+    # bl_export_operator = 'psa_export.export'
     bl_file_extensions = '.psa'
 
     @classmethod
@@ -380,8 +441,9 @@ class PSA_FH_import(FileHandler):
 classes = (
     PSA_OT_import_sequences_select_all,
     PSA_OT_import_sequences_deselect_all,
-    PSA_OT_import_sequences_from_text,
+    PSA_OT_import_sequences_select_from_text,
     PSA_OT_import,
-    PSA_OT_import_multiple,
+    PSA_OT_import_all,
+    PSA_OT_import_drag_and_drop,
     PSA_FH_import,
 )

io_scene_psk_psa/psa/import_/properties.py

@@ -2,20 +2,25 @@ import re
 from fnmatch import fnmatch
 from typing import List
 
-from bpy.props import StringProperty, BoolProperty, CollectionProperty, IntProperty, PointerProperty, EnumProperty, \
-    FloatProperty
+from bpy.props import (
+    BoolProperty,
+    CollectionProperty,
+    EnumProperty,
+    FloatProperty,
+    IntProperty,
+    PointerProperty,
+    StringProperty,
+)
 from bpy.types import PropertyGroup, Text
 
-empty_set = set()
-
 
 class PSA_PG_import_action_list_item(PropertyGroup):
-    action_name: StringProperty(options=empty_set)
-    is_selected: BoolProperty(default=True, options=empty_set)
+    action_name: StringProperty(options=set())
+    is_selected: BoolProperty(default=True, options=set())
 
 
 class PSA_PG_bone(PropertyGroup):
-    bone_name: StringProperty(options=empty_set)
+    bone_name: StringProperty(options=set())
 
 
 class PSA_PG_data(PropertyGroup):
@@ -23,40 +28,52 @@ class PSA_PG_data(PropertyGroup):
     sequence_count: IntProperty(default=0)
 
 
-class PSA_PG_import(PropertyGroup):
-    psa_error: StringProperty(default='')
-    psa: PointerProperty(type=PSA_PG_data)
-    sequence_list: CollectionProperty(type=PSA_PG_import_action_list_item)
-    sequence_list_index: IntProperty(name='', default=0)
+bone_mapping_items = (
+    ('EXACT', 'Exact', 'Bone names must match exactly.', 'EXACT', 0),
+    ('CASE_INSENSITIVE', 'Case Insensitive', 'Bones names must match, ignoring case (e.g., the bone PSA bone \'root\' can be mapped to the armature bone \'Root\')', 'CASE_INSENSITIVE', 1),
+)
+
+fps_source_items = (
+    ('SEQUENCE', 'Sequence', 'The sequence frame rate matches the original frame rate', 'ACTION', 0),
+    ('SCENE', 'Scene', 'The sequence is resampled to the frame rate of the scene', 'SCENE_DATA', 1),
+    ('CUSTOM', 'Custom', 'The sequence is resampled to a custom frame rate', 2),
+)
+
+compression_ratio_source_items = (
+    ('ACTION', 'Action', 'The compression ratio is sourced from the action metadata', 'ACTION', 0),
+    ('CUSTOM', 'Custom', 'The compression ratio is set to a custom value', 1),
+)
+
+class PsaImportMixin:
     should_use_fake_user: BoolProperty(default=True, name='Fake User',
                                        description='Assign each imported action a fake user so that the data block is '
                                                    'saved even it has no users',
-                                       options=empty_set)
+                                       options=set())
     should_use_config_file: BoolProperty(default=True, name='Use Config File',
-                                            description='Use the .config file that is sometimes generated when the PSA '
-                                                        'file is exported from UEViewer. This file contains '
-                                                        'options that can be used to filter out certain bones tracks '
-                                                        'from the imported actions',
-                                            options=empty_set)
+                                         description='Use the .config file that is sometimes generated when the PSA '
+                                                     'file is exported from UEViewer. This file contains '
+                                                     'options that can be used to filter out certain bones tracks '
+                                                     'from the imported actions',
+                                         options=set())
     should_stash: BoolProperty(default=False, name='Stash',
                                description='Stash each imported action as a strip on a new non-contributing NLA track',
-                               options=empty_set)
-    should_use_action_name_prefix: BoolProperty(default=False, name='Prefix Action Name', options=empty_set)
-    action_name_prefix: StringProperty(default='', name='Prefix', options=empty_set)
-    should_overwrite: BoolProperty(default=False, name='Overwrite', options=empty_set,
+                               options=set())
+    should_use_action_name_prefix: BoolProperty(default=False, name='Prefix Action Name', options=set())
+    action_name_prefix: StringProperty(default='', name='Prefix', options=set())
+    should_overwrite: BoolProperty(default=False, name='Overwrite', options=set(),
                                    description='If an action with a matching name already exists, the existing action '
                                                'will have it\'s data overwritten instead of a new action being created')
-    should_write_keyframes: BoolProperty(default=True, name='Keyframes', options=empty_set)
-    should_write_metadata: BoolProperty(default=True, name='Metadata', options=empty_set,
+    should_write_keyframes: BoolProperty(default=True, name='Keyframes', options=set())
+    should_write_metadata: BoolProperty(default=True, name='Metadata', options=set(),
                                         description='Additional data will be written to the custom properties of the '
                                                     'Action (e.g., frame rate)')
     sequence_filter_name: StringProperty(default='', options={'TEXTEDIT_UPDATE'})
-    sequence_filter_is_selected: BoolProperty(default=False, options=empty_set, name='Only Show Selected',
+    sequence_filter_is_selected: BoolProperty(default=False, options=set(), name='Only Show Selected',
                                               description='Only show selected sequences')
-    sequence_use_filter_invert: BoolProperty(default=False, options=empty_set)
+    sequence_use_filter_invert: BoolProperty(default=False, options=set())
     sequence_use_filter_regex: BoolProperty(default=False, name='Regular Expression',
-                                            description='Filter using regular expressions', options=empty_set)
-    select_text: PointerProperty(type=Text)
+                                            description='Filter using regular expressions', options=set())
+
     should_convert_to_samples: BoolProperty(
         default=False,
         name='Convert to Samples',
@@ -65,39 +82,28 @@ class PSA_PG_import(PropertyGroup):
     )
     bone_mapping_mode: EnumProperty(
         name='Bone Mapping',
-        options=empty_set,
+        options=set(),
         description='The method by which bones from the incoming PSA file are mapped to the armature',
-        items=(
-            ('EXACT', 'Exact', 'Bone names must match exactly.', 'EXACT', 0),
-            ('CASE_INSENSITIVE', 'Case Insensitive', 'Bones names must match, ignoring case (e.g., the bone PSA bone '
-             '\'root\' can be mapped to the armature bone \'Root\')', 'CASE_INSENSITIVE', 1),
-        ),
+        items=bone_mapping_items,
         default='CASE_INSENSITIVE'
     )
-    fps_source: EnumProperty(name='FPS Source', items=(
-        ('SEQUENCE', 'Sequence', 'The sequence frame rate matches the original frame rate', 'ACTION', 0),
-        ('SCENE', 'Scene', 'The sequence is resampled to the frame rate of the scene', 'SCENE_DATA', 1),
-        ('CUSTOM', 'Custom', 'The sequence is resampled to a custom frame rate', 2),
-    ))
+    fps_source: EnumProperty(name='FPS Source', items=fps_source_items)
     fps_custom: FloatProperty(
         default=30.0,
         name='Custom FPS',
         description='The frame rate to which the imported sequences will be resampled to',
-        options=empty_set,
+        options=set(),
         min=1.0,
         soft_min=1.0,
         soft_max=60.0,
         step=100,
     )
-    compression_ratio_source: EnumProperty(name='Compression Ratio Source', items=(
-        ('ACTION', 'Action', 'The compression ratio is sourced from the action metadata', 'ACTION', 0),
-        ('CUSTOM', 'Custom', 'The compression ratio is set to a custom value', 1),
-    ))
+    compression_ratio_source: EnumProperty(name='Compression Ratio Source', items=compression_ratio_source_items, default='ACTION')
     compression_ratio_custom: FloatProperty(
         default=1.0,
         name='Custom Compression Ratio',
         description='The compression ratio to apply to the imported sequences',
-        options=empty_set,
+        options=set(),
         min=0.0,
         soft_min=0.0,
         soft_max=1.0,
@@ -110,6 +116,22 @@ class PSA_PG_import(PropertyGroup):
     )
 
 
+# This property group lives "globally" in the scene, since Operators cannot have PointerProperty or CollectionProperty
+# properties.
+class PSA_PG_import(PropertyGroup):
+    psa_error: StringProperty(default='')
+    psa: PointerProperty(type=PSA_PG_data)
+    sequence_list: CollectionProperty(type=PSA_PG_import_action_list_item)
+    sequence_list_index: IntProperty(name='', default=0)
+    sequence_filter_name: StringProperty(default='', options={'TEXTEDIT_UPDATE'})
+    sequence_filter_is_selected: BoolProperty(default=False, options=set(), name='Only Show Selected',
+                                              description='Only show selected sequences')
+    sequence_use_filter_invert: BoolProperty(default=False, options=set())
+    sequence_use_filter_regex: BoolProperty(default=False, name='Regular Expression',
+                                            description='Filter using regular expressions', options=set())
+    select_text: PointerProperty(type=Text)
+
+
 def filter_sequences(pg: PSA_PG_import, sequences) -> List[int]:
     bitflag_filter_item = 1 << 30
     flt_flags = [bitflag_filter_item] * len(sequences)

io_scene_psk_psa/psa/importer.py

@@ -1,37 +1,52 @@
 import typing
-from typing import List, Optional
+from typing import Iterable, List, Optional, cast as typing_cast
 
 import bpy
 import numpy as np
-from bpy.types import FCurve, Object, Context
+from bpy.types import Armature, Context, FCurve, Object
 from mathutils import Vector, Quaternion
 
 from .config import PsaConfig, REMOVE_TRACK_LOCATION, REMOVE_TRACK_ROTATION
-from .data import Psa
 from .reader import PsaReader
+from ..shared.data import PsxBone
 
 
 class PsaImportOptions(object):
-    def __init__(self):
-        self.should_use_fake_user = False
-        self.should_stash = False
-        self.sequence_names = []
-        self.should_overwrite = False
-        self.should_write_keyframes = True
-        self.should_write_metadata = True
-        self.action_name_prefix = ''
-        self.should_convert_to_samples = False
-        self.bone_mapping_mode = 'CASE_INSENSITIVE'
-        self.fps_source = 'SEQUENCE'
-        self.fps_custom: float = 30.0
-        self.translation_scale: float = 1.0
-        self.should_use_config_file = True
-        self.psa_config: PsaConfig = PsaConfig()
+    def __init__(self,
+                 action_name_prefix: str = '',
+                 bone_mapping_mode: str = 'CASE_INSENSITIVE',
+                 fps_custom: float = 30.0,
+                 fps_source: str = 'SEQUENCE',
+                 psa_config: PsaConfig = PsaConfig(),
+                 sequence_names: List[str] = None,
+                 should_convert_to_samples: bool = False,
+                 should_overwrite: bool = False,
+                 should_stash: bool = False,
+                 should_use_config_file: bool = True,
+                 should_use_fake_user: bool = False,
+                 should_write_keyframes: bool = True,
+                 should_write_metadata: bool = True,
+                 translation_scale: float = 1.0
+                 ):
+        self.action_name_prefix = action_name_prefix
+        self.bone_mapping_mode = bone_mapping_mode
+        self.fps_custom = fps_custom
+        self.fps_source = fps_source
+        self.psa_config = psa_config
+        self.sequence_names = sequence_names if sequence_names is not None else []
+        self.should_convert_to_samples = should_convert_to_samples
+        self.should_overwrite = should_overwrite
+        self.should_stash = should_stash
+        self.should_use_config_file = should_use_config_file
+        self.should_use_fake_user = should_use_fake_user
+        self.should_write_keyframes = should_write_keyframes
+        self.should_write_metadata = should_write_metadata
+        self.translation_scale = translation_scale
 
 
 class ImportBone(object):
-    def __init__(self, psa_bone: Psa.Bone):
-        self.psa_bone: Psa.Bone = psa_bone
+    def __init__(self, psa_bone: PsxBone):
+        self.psa_bone: PsxBone = psa_bone
         self.parent: Optional[ImportBone] = None
         self.armature_bone = None
         self.pose_bone = None
@@ -41,7 +56,7 @@ class ImportBone(object):
         self.fcurves: List[FCurve] = []
 
 
-def _calculate_fcurve_data(import_bone: ImportBone, key_data: typing.Iterable[float]):
+def _calculate_fcurve_data(import_bone: ImportBone, key_data: Iterable[float]):
     # Convert world-space transforms to local-space transforms.
     key_rotation = Quaternion(key_data[0:4])
     key_location = Vector(key_data[4:])
@@ -68,7 +83,7 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
     """
     @param psa_bone_name: The name of the PSA bone.
     @param armature_bone_names: The names of the bones in the armature.
-    @param bone_mapping_mode: One of 'EXACT' or 'CASE_INSENSITIVE'.
+    @param bone_mapping_mode: One of `['EXACT', 'CASE_INSENSITIVE']`.
     @return: The index of the armature bone that corresponds to the given PSA bone, or None if no such bone exists.
     """
     for armature_bone_index, armature_bone_name in enumerate(armature_bone_names):
@@ -80,24 +95,27 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
                 return armature_bone_index
     return None
 
-def _get_sample_frame_times(source_frame_count: int, frame_step: float) -> typing.Iterable[float]:
-    # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
-    #  fractional frame).
-    time = 0.0
-    while time < source_frame_count - 1:
-        yield time
-        time += frame_step
-    yield source_frame_count - 1
-
 
 def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, frame_step: float = 1.0) -> np.ndarray:
     """
     Resamples the sequence data matrix to the target frame count.
+
     @param sequence_data_matrix: FxBx7 matrix where F is the number of frames, B is the number of bones, and X is the
     number of data elements per bone.
     @param frame_step: The step between frames in the resampled sequence.
     @return: The resampled sequence data matrix, or sequence_data_matrix if no resampling is necessary.
     """
+
+    def _get_sample_frame_times(source_frame_count: int, frame_step: float) -> Iterable[float]:
+        # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
+        #  fractional frame).
+        assert frame_step > 0.0, 'Frame step must be greater than 0'
+        time = 0.0
+        while time < source_frame_count - 1:
+            yield time
+            time += frame_step
+        yield source_frame_count - 1
+
     if frame_step == 1.0:
         # No resampling is necessary.
         return sequence_data_matrix
@@ -130,7 +148,7 @@ def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, frame_step:
 def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object, options: PsaImportOptions) -> PsaImportResult:
     result = PsaImportResult()
     sequences = [psa_reader.sequences[x] for x in options.sequence_names]
-    armature_data = typing.cast(bpy.types.Armature, armature_object.data)
+    armature_data = typing_cast(Armature, armature_object.data)
 
     # Create an index mapping from bones in the PSA to bones in the target armature.
     psa_to_armature_bone_indices = {}
@@ -245,7 +263,7 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             case 'SEQUENCE':
                 target_fps = sequence.fps
             case _:
-                raise ValueError(f'Unknown FPS source: {options.fps_source}')
+                assert False, f'Invalid FPS source: {options.fps_source}'
 
         if options.should_write_keyframes:
             # Remove existing f-curves.

io_scene_psk_psa/psa/reader.py

@@ -1,8 +1,10 @@
-import ctypes
+from ctypes import sizeof
+from typing import List
 
 import numpy as np
 
-from .data import *
+from .data import Psa, PsxBone
+from ..shared.data import Section
 
 
 def _try_fix_cue4parse_issue_103(sequences) -> bool:
@@ -34,6 +36,12 @@ class PsaReader(object):
         self.fp = open(path, 'rb')
         self.psa: Psa = self._read(self.fp)
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.fp.close()
+
     @property
     def bones(self):
         return self.psa.bones
@@ -45,6 +53,7 @@ class PsaReader(object):
     def read_sequence_data_matrix(self, sequence_name: str) -> np.ndarray:
         """
         Reads and returns the data matrix for the given sequence.
+        
         @param sequence_name: The name of the sequence.
         @return: An FxBx7 matrix where F is the number of frames, B is the number of bones.
         """
@@ -95,11 +104,11 @@ class PsaReader(object):
         psa = Psa()
         while fp.read(1):
             fp.seek(-1, 1)
-            section = Section.from_buffer_copy(fp.read(ctypes.sizeof(Section)))
+            section = Section.from_buffer_copy(fp.read(sizeof(Section)))
             if section.name == b'ANIMHEAD':
                 pass
             elif section.name == b'BONENAMES':
-                PsaReader._read_types(fp, Psa.Bone, section, psa.bones)
+                PsaReader._read_types(fp, PsxBone, section, psa.bones)
             elif section.name == b'ANIMINFO':
                 sequences = []
                 PsaReader._read_types(fp, Psa.Sequence, section, sequences)

io_scene_psk_psa/psa/writer.py

@@ -2,7 +2,7 @@ from ctypes import Structure, sizeof
 from typing import Type
 
 from .data import Psa
-from ..shared.data import Section
+from ..shared.data import PsxBone, Section
 
 
 def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
@@ -20,6 +20,6 @@ def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list
 def write_psa(psa: Psa, path: str):
     with open(path, 'wb') as fp:
         write_section(fp, b'ANIMHEAD')
-        write_section(fp, b'BONENAMES', Psa.Bone, psa.bones)
+        write_section(fp, b'BONENAMES', PsxBone, psa.bones)
         write_section(fp, b'ANIMINFO', Psa.Sequence, list(psa.sequences.values()))
         write_section(fp, b'ANIMKEYS', Psa.Key, psa.keys)

io_scene_psk_psa/psk/builder.py

@@ -1,61 +1,51 @@
-import typing
-from typing import Optional
-
 import bmesh
+import bpy
 import numpy as np
-from bpy.types import Material, Collection, Context
-from mathutils import Matrix, Vector
-
-from .data import *
+from bpy.types import Armature, Collection, Context, Depsgraph, Object
+from mathutils import Matrix
+from typing import Dict, Generator, Iterable, List, Optional, Set, Tuple, cast as typing_cast
+from .data import Psk
 from .properties import triangle_type_and_bit_flags_to_poly_flags
-from ..shared.dfs import dfs_collection_objects, dfs_view_layer_objects, DfsObject
-from ..shared.helpers import *
+from ..shared.data import Vector3
+from ..shared.dfs import DfsObject, dfs_collection_objects, dfs_view_layer_objects
+from ..shared.helpers import (
+    convert_string_to_cp1252_bytes,
+    create_psx_bones,
+    get_coordinate_system_transform,
+)
 
 
 class PskInputObjects(object):
     def __init__(self):
-        self.mesh_objects: List[DfsObject] = []
-        self.armature_object: Optional[Object] = None
+        self.mesh_dfs_objects: List[DfsObject] = []
+        self.armature_objects: Set[Object] = set()
 
 
 class PskBuildOptions(object):
     def __init__(self):
         self.bone_filter_mode = 'ALL'
-        self.bone_collection_indices: List[int] = []
+        self.bone_collection_indices: List[Tuple[str, int]] = []
         self.object_eval_state = 'EVALUATED'
-        self.materials: List[Material] = []
+        self.material_order_mode = 'AUTOMATIC'
+        self.material_name_list: List[str] = []
         self.scale = 1.0
         self.export_space = 'WORLD'
         self.forward_axis = 'X'
         self.up_axis = 'Z'
+        self.root_bone_name = 'ROOT'
 
 
-def get_vector_from_axis_identifier(axis_identifier: str) -> Vector:
-    match axis_identifier:
-        case 'X':
-            return Vector((1.0, 0.0, 0.0))
-        case 'Y':
-            return Vector((0.0, 1.0, 0.0))
-        case 'Z':
-            return Vector((0.0, 0.0, 1.0))
-        case '-X':
-            return Vector((-1.0, 0.0, 0.0))
-        case '-Y':
-            return Vector((0.0, -1.0, 0.0))
-        case '-Z':
-            return Vector((0.0, 0.0, -1.0))
-
-
-def get_coordinate_system_transform(forward_axis: str = 'X', up_axis: str = 'Z') -> Matrix:
-    forward = get_vector_from_axis_identifier(forward_axis)
-    up = get_vector_from_axis_identifier(up_axis)
-    left = up.cross(forward)
-    return Matrix((
-        (forward.x, forward.y, forward.z, 0.0),
-        (left.x, left.y, left.z, 0.0),
-        (up.x, up.y, up.z, 0.0),
-        (0.0, 0.0, 0.0, 1.0)
-    )).inverted()
+def get_materials_for_mesh_objects(depsgraph: Depsgraph, mesh_objects: Iterable[Object]):
+    yielded_materials = set()
+    for mesh_object in mesh_objects:
+        evaluated_mesh_object = mesh_object.evaluated_get(depsgraph)
+        for i, material_slot in enumerate(evaluated_mesh_object.material_slots):
+            material = material_slot.material
+            if material is None:
+                raise RuntimeError('Material slot cannot be empty (index ' + str(i) + ')')
+            if material not in yielded_materials:
+                yielded_materials.add(material)
+                yield material
 
 
 def get_mesh_objects_for_collection(collection: Collection) -> Iterable[DfsObject]:
@@ -68,36 +58,34 @@ def get_mesh_objects_for_context(context: Context) -> Iterable[DfsObject]:
             yield dfs_object
 
 
-def get_armature_for_mesh_objects(mesh_objects: Iterable[Object]) -> Optional[Object]:
+def get_armature_for_mesh_object(mesh_object: Object) -> Optional[Object]:
+    for modifier in mesh_object.modifiers:
+        if modifier.type == 'ARMATURE':
+            return modifier.object
+    return None
+
+
+def get_armatures_for_mesh_objects(mesh_objects: Iterable[Object]) -> Generator[Object, None, None]:
     # Ensure that there are either no armature modifiers (static mesh) or that there is exactly one armature modifier
     # object shared between all meshes.
-    armature_modifier_objects = set()
+    armature_objects = set()
     for mesh_object in mesh_objects:
         modifiers = [x for x in mesh_object.modifiers if x.type == 'ARMATURE']
         if len(modifiers) == 0:
             continue
-        elif len(modifiers) > 1:
-            raise RuntimeError(f'Mesh "{mesh_object.name}" must have only one armature modifier')
-        armature_modifier_objects.add(modifiers[0].object)
-
-    if len(armature_modifier_objects) > 1:
-        armature_modifier_names = [x.name for x in armature_modifier_objects]
-        raise RuntimeError(
-            f'All meshes must have the same armature modifier, encountered {len(armature_modifier_names)} ({", ".join(armature_modifier_names)})')
-    elif len(armature_modifier_objects) == 1:
-        return list(armature_modifier_objects)[0]
-    else:
-        return None
+        if modifiers[0].object in armature_objects:
+            continue
+        yield modifiers[0].object
 
 
-def _get_psk_input_objects(mesh_objects: Iterable[DfsObject]) -> PskInputObjects:
-    mesh_objects = list(mesh_objects)
-    if len(mesh_objects) == 0:
+def _get_psk_input_objects(mesh_dfs_objects: Iterable[DfsObject]) -> PskInputObjects:
+    mesh_dfs_objects = list(mesh_dfs_objects)
+    if len(mesh_dfs_objects) == 0:
         raise RuntimeError('At least one mesh must be selected')
 
     input_objects = PskInputObjects()
-    input_objects.mesh_objects = mesh_objects
-    input_objects.armature_object = get_armature_for_mesh_objects([x.obj for x in mesh_objects])
+    input_objects.mesh_dfs_objects = mesh_dfs_objects
+    input_objects.armature_objects |= set(get_armatures_for_mesh_objects(map(lambda x: x.obj, mesh_dfs_objects)))
 
     return input_objects
 
@@ -120,114 +108,78 @@ class PskBuildResult(object):
         self.warnings: List[str] = []
 
 
-def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions) -> PskBuildResult:
-    armature_object: bpy.types.Object = input_objects.armature_object
+def _get_mesh_export_space_matrix(armature_object: Optional[Object], export_space: str) -> Matrix:
+    if armature_object is None:
+        return Matrix.Identity(4)
+
+    def get_object_space_matrix(obj: Object) -> Matrix:
+        translation, rotation, _ = obj.matrix_world.decompose()
+        # We neutralize the scale here because the scale is already applied to the mesh objects implicitly.
+        return Matrix.Translation(translation) @ rotation.to_matrix().to_4x4()
+
+    match export_space:
+        case 'WORLD':
+            return Matrix.Identity(4)
+        case 'ARMATURE':
+            return get_object_space_matrix(armature_object).inverted()
+        case 'ROOT':
+            armature_data = typing_cast(Armature, armature_object.data)
+            armature_space_matrix = get_object_space_matrix(armature_object) @ armature_data.bones[0].matrix_local
+            return armature_space_matrix.inverted()
+        case _:
+            assert False, f'Invalid export space: {export_space}'
+
+
+def _get_material_name_indices(obj: Object, material_names: List[str]) -> Iterable[int]:
+    """
+    Returns the index of the material in the list of material names.
+    If the material is not found, the index 0 is returned.
+    """
+    for material_slot in obj.material_slots:
+        if material_slot.material is None:
+            yield 0
+        else:
+            try:
+                yield material_names.index(material_slot.material.name)
+            except ValueError:
+                yield 0
+
+
+def build_psk(context: Context, input_objects: PskInputObjects, options: PskBuildOptions) -> PskBuildResult:
+    armature_objects = list(input_objects.armature_objects)
 
     result = PskBuildResult()
     psk = Psk()
-    bones = []
 
-    def get_export_space_matrix():
-        match options.export_space:
-            case 'WORLD':
-                return Matrix.Identity(4)
-            case 'ARMATURE':
-                if armature_object is not None:
-                    return armature_object.matrix_world.inverted()
-                else:
-                    return Matrix.Identity(4)
-            case _:
-                raise ValueError(f'Invalid export space: {options.export_space}')
+    psx_bone_create_result = create_psx_bones(
+        armature_objects=armature_objects,
+        export_space=options.export_space,
+        forward_axis=options.forward_axis,
+        up_axis=options.up_axis,
+        scale=options.scale,
+        root_bone_name=options.root_bone_name,
+        bone_filter_mode=options.bone_filter_mode,
+        bone_collection_indices=options.bone_collection_indices
+    )
 
-    coordinate_system_matrix = get_coordinate_system_transform(options.forward_axis, options.up_axis)
-    coordinate_system_default_rotation = coordinate_system_matrix.to_quaternion()
+    psk.bones = [psx_bone for psx_bone, _ in psx_bone_create_result.bones]
 
-    export_space_matrix = get_export_space_matrix()  # TODO: maybe neutralize the scale here?
-    scale_matrix = coordinate_system_matrix @ Matrix.Scale(options.scale, 4)
+    # Materials
+    match options.material_order_mode:
+        case 'AUTOMATIC':
+            mesh_objects = [dfs_object.obj for dfs_object in input_objects.mesh_dfs_objects]
+            materials = list(get_materials_for_mesh_objects(context.evaluated_depsgraph_get(), mesh_objects))
+        case 'MANUAL':
+            # The material name list may contain materials that are not on the mesh objects.
+            # Therefore, we can take the material_name_list as gospel and simply use it as a lookup table.
+            # If a look-up fails, replace it with an empty material.
+            materials = [bpy.data.materials.get(x.material_name, None) for x in options.material_name_list]
+        case _:
+            assert False, f'Invalid material order mode: {options.material_order_mode}'
 
-    if armature_object is None or len(armature_object.data.bones) == 0:
-        # If the mesh has no armature object or no bones, simply assign it a dummy bone at the root to satisfy the
-        # requirement that a PSK file must have at least one bone.
-        psk_bone = Psk.Bone()
-        psk_bone.name = bytes('root', encoding='windows-1252')
-        psk_bone.flags = 0
-        psk_bone.children_count = 0
-        psk_bone.parent_index = 0
-        psk_bone.location = Vector3.zero()
-        psk_bone.rotation = coordinate_system_default_rotation
-        psk.bones.append(psk_bone)
-    else:
-        bone_names = get_export_bone_names(armature_object, options.bone_filter_mode, options.bone_collection_indices)
-        armature_data = typing.cast(Armature, armature_object.data)
-        bones = [armature_data.bones[bone_name] for bone_name in bone_names]
-
-        for bone in bones:
-            psk_bone = Psk.Bone()
-            try:
-                psk_bone.name = bytes(bone.name, encoding='windows-1252')
-            except UnicodeEncodeError:
-                raise RuntimeError(
-                    f'Bone name "{bone.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
-            psk_bone.flags = 0
-            psk_bone.children_count = 0
-
-            try:
-                parent_index = bones.index(bone.parent)
-                psk_bone.parent_index = parent_index
-                psk.bones[parent_index].children_count += 1
-            except ValueError:
-                psk_bone.parent_index = 0
-
-            if bone.parent is not None:
-                rotation = bone.matrix.to_quaternion().conjugated()
-                inverse_parent_rotation = bone.parent.matrix.to_quaternion().inverted()
-                parent_head = inverse_parent_rotation @ bone.parent.head
-                parent_tail = inverse_parent_rotation @ bone.parent.tail
-                location = (parent_tail - parent_head) + bone.head
-            else:
-                def get_armature_local_matrix():
-                    match options.export_space:
-                        case 'WORLD':
-                            return armature_object.matrix_world
-                        case 'ARMATURE':
-                            return Matrix.Identity(4)
-                        case _:
-                            raise ValueError(f'Invalid export space: {options.export_space}')
-
-                armature_local_matrix = get_armature_local_matrix()
-                location = armature_local_matrix @ bone.head
-                bone_rotation = bone.matrix.to_quaternion().conjugated()
-                local_rotation = armature_local_matrix.to_3x3().to_quaternion().conjugated()
-                rotation = bone_rotation @ local_rotation
-                rotation.conjugate()
-                rotation = coordinate_system_default_rotation @ rotation
-
-            location = scale_matrix @ location
-
-            # If the armature object has been scaled, we need to scale the bone's location to match.
-            _, _, armature_object_scale = armature_object.matrix_world.decompose()
-            location.x *= armature_object_scale.x
-            location.y *= armature_object_scale.y
-            location.z *= armature_object_scale.z
-
-            psk_bone.location.x = location.x
-            psk_bone.location.y = location.y
-            psk_bone.location.z = location.z
-
-            psk_bone.rotation.w = rotation.w
-            psk_bone.rotation.x = rotation.x
-            psk_bone.rotation.y = rotation.y
-            psk_bone.rotation.z = rotation.z
-
-            psk.bones.append(psk_bone)
-
-    # MATERIALS
-    for material in options.materials:
+    for material in materials:
         psk_material = Psk.Material()
-        try:
-            psk_material.name = bytes(material.name, encoding='windows-1252')
-        except UnicodeEncodeError:
-            raise RuntimeError(f'Material name "{material.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
+        psk_material.name = convert_string_to_cp1252_bytes(material.name if material else 'None')
         psk_material.texture_index = len(psk.materials)
         psk_material.poly_flags = triangle_type_and_bit_flags_to_poly_flags(material.psk.mesh_triangle_type,
                                                                             material.psk.mesh_triangle_bit_flags)
@@ -241,100 +193,103 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
     if len(psk.materials) == 0:
         # Add a default material if no materials are present.
         psk_material = Psk.Material()
-        psk_material.name = bytes('None', encoding='windows-1252')
+        psk_material.name = convert_string_to_cp1252_bytes('None')
         psk.materials.append(psk_material)
 
-    context.window_manager.progress_begin(0, len(input_objects.mesh_objects))
+    context.window_manager.progress_begin(0, len(input_objects.mesh_dfs_objects))
 
-    material_names = [m.name for m in options.materials]
+    coordinate_system_matrix = get_coordinate_system_transform(options.forward_axis, options.up_axis)
 
-    for object_index, input_mesh_object in enumerate(input_objects.mesh_objects):
+    # Calculate the export spaces for the armature objects.
+    # This is used later to transform the mesh object geometry into the export space.
+    armature_mesh_export_space_matrices: Dict[Optional[Object], Matrix] = {None: Matrix.Identity(4)}
+    for armature_object in armature_objects:
+        armature_mesh_export_space_matrices[armature_object] = _get_mesh_export_space_matrix(armature_object, options.export_space)
 
-        obj, instance_objects, matrix_world = input_mesh_object.obj, input_mesh_object.instance_objects, input_mesh_object.matrix_world
+    scale_matrix = Matrix.Scale(options.scale, 4)
+
+    original_armature_object_pose_positions = {a: a.data.pose_position for a in armature_objects}
+
+    # Temporarily force the armature into the rest position.
+    # We will undo this later.
+    for armature_object in armature_objects:
+        armature_object.data.pose_position = 'REST'
+
+    material_names = [m.name for m in materials]
+
+    for object_index, input_mesh_object in enumerate(input_objects.mesh_dfs_objects):
+        obj, matrix_world = input_mesh_object.obj, input_mesh_object.matrix_world
+
+        armature_object = get_armature_for_mesh_object(obj)
 
         should_flip_normals = False
 
-        def get_material_name_indices(obj: Object, material_names: List[str]) -> Iterable[int]:
-            '''
-            Returns the index of the material in the list of material names.
-            If the material is not found, the index 0 is returned.
-            '''
-            for material_slot in obj.material_slots:
-                if material_slot.material is None:
-                    yield 0
-                else:
-                    try:
-                        yield material_names.index(material_slot.material.name)
-                    except ValueError:
-                        yield 0
-
-        # MATERIALS
-        material_indices = list(get_material_name_indices(obj, material_names))
+        # Material indices
+        material_indices = list(_get_material_name_indices(obj, material_names))
 
         if len(material_indices) == 0:
             # Add a default material if no materials are present.
             material_indices = [0]
 
-        # MESH DATA
+        # Store the reference to the evaluated object and data so that we can clean them up later.
+        evaluated_mesh_object = None
+        evaluated_mesh_data = None
+
+        # Mesh data
         match options.object_eval_state:
             case 'ORIGINAL':
                 mesh_object = obj
                 mesh_data = obj.data
             case 'EVALUATED':
                 # Create a copy of the mesh object after non-armature modifiers are applied.
-
-                # Temporarily force the armature into the rest position.
-                # We will undo this later.
-                old_pose_position = None
-                if armature_object is not None:
-                    old_pose_position = armature_object.data.pose_position
-                    armature_object.data.pose_position = 'REST'
-
                 depsgraph = context.evaluated_depsgraph_get()
                 bm = bmesh.new()
 
                 try:
                     bm.from_object(obj, depsgraph)
-                except ValueError:
+                except ValueError as e:
+                    del bm
                     raise RuntimeError(f'Object "{obj.name}" is not evaluated.\n'
-                    'This is likely because the object is in a collection that has been excluded from the view layer.')
+                    'This is likely because the object is in a collection that has been excluded from the view layer.') from e
 
-                mesh_data = bpy.data.meshes.new('')
+                evaluated_mesh_data = bpy.data.meshes.new('')
+                mesh_data = evaluated_mesh_data
                 bm.to_mesh(mesh_data)
                 del bm
-                mesh_object = bpy.data.objects.new('', mesh_data)
+                evaluated_mesh_object = bpy.data.objects.new('', mesh_data)
+                mesh_object =  evaluated_mesh_object
                 mesh_object.matrix_world = matrix_world
 
                 # Extract the scale from the matrix.
                 _, _, scale = matrix_world.decompose()
 
-                # Negative scaling in Blender results in inverted normals after the scale is applied. However, if the scale
-                # is not applied, the normals will appear unaffected in the viewport. The evaluated mesh data used in the
-                # export will have the scale applied, but this behavior is not obvious to the user.
+                # Negative scaling in Blender results in inverted normals after the scale is applied. However, if the
+                # scale is not applied, the normals will appear unaffected in the viewport. The evaluated mesh data used
+                # in the export will have the scale applied, but this behavior is not obvious to the user.
                 #
-                # In order to have the exporter be as WYSIWYG as possible, we need to check for negative scaling and invert
-                # the normals if necessary. If two axes have negative scaling and the third has positive scaling, the
-                # normals will be correct. We can detect this by checking if the number of negative scaling axes is odd. If
-                # it is, we need to invert the normals of the mesh by swapping the order of the vertices in each face.
-                should_flip_normals = sum(1 for x in scale if x < 0) % 2 == 1
+                # In order to have the exporter be as WYSIWYG as possible, we need to check for negative scaling and
+                # invert the normals if necessary. If two axes have negative scaling and the third has positive scaling,
+                # the normals will be correct. We can detect this by checking if the number of negative scaling axes is
+                # odd. If it is, we need to invert the normals of the mesh by swapping the order of the vertices in each
+                # face.
+                if not should_flip_normals:
+                    should_flip_normals = sum(1 for x in scale if x < 0) % 2 == 1
 
                 # Copy the vertex groups
                 for vertex_group in obj.vertex_groups:
                     mesh_object.vertex_groups.new(name=vertex_group.name)
-
-                # Restore the previous pose position on the armature.
-                if old_pose_position is not None:
-                    armature_object.data.pose_position = old_pose_position
             case _:
-                raise ValueError(f'Invalid object evaluation state: {options.object_eval_state}')
+                assert False, f'Invalid object evaluation state: {options.object_eval_state}'
 
+        mesh_export_space_matrix = armature_mesh_export_space_matrices[armature_object]
+        vertex_transform_matrix = scale_matrix @ coordinate_system_matrix @ mesh_export_space_matrix
+        point_transform_matrix = vertex_transform_matrix @ mesh_object.matrix_world
+
+        # Vertices
         vertex_offset = len(psk.points)
-        matrix_world = scale_matrix @ export_space_matrix @ mesh_object.matrix_world
-
-        # VERTICES
         for vertex in mesh_data.vertices:
             point = Vector3()
-            v = matrix_world @ vertex.co
+            v = point_transform_matrix @ vertex.co
             point.x = v.x
             point.y = v.y
             point.z = v.z
@@ -342,7 +297,7 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
 
         uv_layer = mesh_data.uv_layers.active.data
 
-        # WEDGES
+        # Wedges
         mesh_data.calc_loop_triangles()
 
         # Build a list of non-unique wedges.
@@ -359,7 +314,7 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
             for loop_index in triangle.loops:
                 wedges[loop_index].material_index = material_indices[triangle.material_index]
 
-        # Populate the list of wedges with unique wedges & build a look-up table of loop indices to wedge indices
+        # Populate the list of wedges with unique wedges & build a look-up table of loop indices to wedge indices.
         wedge_indices = dict()
         loop_wedge_indices = np.full(len(mesh_data.loops), -1)
         for loop_index, wedge in enumerate(wedges):
@@ -372,7 +327,7 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
                 psk.wedges.append(wedge)
                 loop_wedge_indices[loop_index] = wedge_index
 
-        # FACES
+        # Faces
         poly_groups, groups = mesh_data.calc_smooth_groups(use_bitflags=True)
         psk_face_start_index = len(psk.faces)
         for f in mesh_data.loop_triangles:
@@ -389,17 +344,19 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
             for face in psk.faces[psk_face_start_index:]:
                 face.wedge_indices[0], face.wedge_indices[2] = face.wedge_indices[2], face.wedge_indices[0]
 
-        # WEIGHTS
+        # Weights
         if armature_object is not None:
-            armature_data = typing.cast(Armature, armature_object.data)
+            armature_data = typing_cast(Armature, armature_object.data)
+            bone_index_offset = psx_bone_create_result.armature_object_root_bone_indices[armature_object]
             # Because the vertex groups may contain entries for which there is no matching bone in the armature,
             # we must filter them out and not export any weights for these vertex groups.
-            bone_names = [x.name for x in bones]
+
+            bone_names = psx_bone_create_result.armature_object_bone_names[armature_object]
             vertex_group_names = [x.name for x in mesh_object.vertex_groups]
-            vertex_group_bone_indices = dict()
+            vertex_group_bone_indices: Dict[int, int] = dict()
             for vertex_group_index, vertex_group_name in enumerate(vertex_group_names):
                 try:
-                    vertex_group_bone_indices[vertex_group_index] = bone_names.index(vertex_group_name)
+                    vertex_group_bone_indices[vertex_group_index] = bone_names.index(vertex_group_name) + bone_index_offset
                 except ValueError:
                     # The vertex group does not have a matching bone in the list of bones to be exported.
                     # Check to see if there is an associated bone for this vertex group that exists in the armature.
@@ -409,8 +366,7 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
                         bone = armature_data.bones[vertex_group_name]
                         while bone is not None:
                             try:
-                                bone_index = bone_names.index(bone.name)
-                                vertex_group_bone_indices[vertex_group_index] = bone_index
+                                vertex_group_bone_indices[vertex_group_index] = bone_names.index(bone.name) + bone_index_offset
                                 break
                             except ValueError:
                                 bone = bone.parent
@@ -439,24 +395,35 @@ def build_psk(context, input_objects: PskInputObjects, options: PskBuildOptions)
                     psk.weights.append(w)
                     vertices_assigned_weights[vertex_index] = True
 
-            # Assign vertices that have not been assigned weights to the root bone.
+            # Assign vertices that have not been assigned weights to the root bone of the armature.
+            fallback_weight_bone_index = psx_bone_create_result.armature_object_root_bone_indices[armature_object]
             for vertex_index, assigned in enumerate(vertices_assigned_weights):
                 if not assigned:
                     w = Psk.Weight()
-                    w.bone_index = 0
+                    w.bone_index = fallback_weight_bone_index
                     w.point_index = vertex_offset + vertex_index
                     w.weight = 1.0
                     psk.weights.append(w)
 
-        if options.object_eval_state == 'EVALUATED':
+        if evaluated_mesh_object is not None:
             bpy.data.objects.remove(mesh_object)
+            del mesh_object
+
+        if evaluated_mesh_data is not None:
             bpy.data.meshes.remove(mesh_data)
             del mesh_data
 
         context.window_manager.progress_update(object_index)
 
+    # Restore the original pose position of the armature objects.
+    for armature_object, pose_position in original_armature_object_pose_positions.items():
+        armature_object.data.pose_position = pose_position
+
     context.window_manager.progress_end()
 
+    # https://github.com/DarklightGames/io_scene_psk_psa/issues/129.
+    psk.sort_and_normalize_weights()
+
     result.psk = psk
 
     return result

io_scene_psk_psa/psk/data.py

@@ -1,6 +1,7 @@
+from ctypes import Structure, c_uint32, c_float, c_int32, c_uint8, c_int8, c_int16, c_char, c_uint16
 from typing import List
 
-from ..shared.data import *
+from ..shared.data import Vector3, Quaternion, Color, Vector2, PsxBone
 
 
 class Psk(object):
@@ -112,13 +113,38 @@ class Psk(object):
     def has_morph_data(self):
         return len(self.morph_infos) > 0
     
+    def sort_and_normalize_weights(self):
+        self.weights.sort(key=lambda x: x.point_index)
+
+        weight_index = 0
+        weight_total = len(self.weights)
+
+        while weight_index < weight_total:
+            point_index = self.weights[weight_index].point_index
+            weight_sum = self.weights[weight_index].weight
+            point_weight_total = 1
+
+            # Calculate the sum of weights for the current point_index.
+            for i in range(weight_index + 1, weight_total):
+                if self.weights[i].point_index != point_index:
+                    break
+                weight_sum += self.weights[i].weight
+                point_weight_total += 1
+
+            # Normalize the weights for the current point_index.
+            for i in range(weight_index, weight_index + point_weight_total):
+                self.weights[i].weight /= weight_sum
+
+            # Move to the next group of weights.
+            weight_index += point_weight_total
+    
     def __init__(self):
         self.points: List[Vector3] = []
         self.wedges: List[Psk.Wedge] = []
         self.faces: List[Psk.Face] = []
         self.materials: List[Psk.Material] = []
         self.weights: List[Psk.Weight] = []
-        self.bones: List[Psk.Bone] = []
+        self.bones: List[PsxBone] = []
         self.extra_uvs: List[Vector2] = []
         self.vertex_colors: List[Color] = []
         self.vertex_normals: List[Vector3] = []

io_scene_psk_psa/psk/export/operators.py

@@ -1,33 +1,32 @@
-from typing import List, Optional, cast, Iterable
+from pathlib import Path
+from typing import Iterable, List, Optional, cast as typing_cast
 
 import bpy
-from bpy.props import StringProperty
-from bpy.types import Operator, Context, Object, Collection, SpaceProperties, Depsgraph, Material
+from bpy.props import BoolProperty, StringProperty
+from bpy.types import Collection, Context, Depsgraph, Material, Object, Operator, SpaceProperties
 from bpy_extras.io_utils import ExportHelper
 
-from .properties import add_psk_export_properties
-from ..builder import build_psk, PskBuildOptions, get_psk_input_objects_for_context, \
-    get_psk_input_objects_for_collection
+from .properties import PskExportMixin
+from ..builder import (
+    PskBuildOptions,
+    build_psk,
+    get_materials_for_mesh_objects,
+    get_psk_input_objects_for_collection,
+    get_psk_input_objects_for_context,
+)
 from ..writer import write_psk
 from ...shared.helpers import populate_bone_collection_list
 from ...shared.ui import draw_bone_filter_mode
 
 
-def get_materials_for_mesh_objects(depsgraph: Depsgraph, mesh_objects: Iterable[Object]):
-    materials = []
-    for mesh_object in mesh_objects:
-        evaluated_mesh_object = mesh_object.evaluated_get(depsgraph)
-        for i, material_slot in enumerate(evaluated_mesh_object.material_slots):
-            material = material_slot.material
-            if material is None:
-                raise RuntimeError('Material slot cannot be empty (index ' + str(i) + ')')
-            if material not in materials:
-                materials.append(material)
-    return materials
+def populate_material_name_list(depsgraph: Depsgraph, mesh_objects: Iterable[Object], material_list):
+    materials = list(get_materials_for_mesh_objects(depsgraph, mesh_objects))
 
+    # Order the mesh object materials by the order any existing entries in the material list.
+    # This way, if the user has already set up the material list, we don't change the order.
+    material_names = [x.material_name for x in material_list]
+    materials = get_sorted_materials_by_names(materials, material_names)
 
-def populate_material_name_list(depsgraph: Depsgraph, mesh_objects, material_list):
-    materials = get_materials_for_mesh_objects(depsgraph, mesh_objects)
     material_list.clear()
     for index, material in enumerate(materials):
         m = material_list.add()
@@ -40,10 +39,10 @@ def get_collection_from_context(context: Context) -> Optional[Collection]:
     if context.space_data.type != 'PROPERTIES':
         return None
 
-    space_data = cast(SpaceProperties, context.space_data)
+    space_data = typing_cast(SpaceProperties, context.space_data)
 
     if space_data.use_pin_id:
-        return cast(Collection, space_data.pin_id)
+        return typing_cast(Collection, space_data.pin_id)
     else:
         return context.collection
 
@@ -59,8 +58,8 @@ def get_collection_export_operator_from_context(context: Context) -> Optional[ob
     return exporter.export_properties
 
 
-class PSK_OT_populate_bone_collection_list(Operator):
-    bl_idname = 'psk_export.populate_bone_collection_list'
+class PSK_OT_bone_collection_list_populate(Operator):
+    bl_idname = 'psk.bone_collection_list_populate'
     bl_label = 'Populate Bone Collection List'
     bl_description = 'Populate the bone collection list from the armature that will be used in this collection export'
     bl_options = {'INTERNAL'}
@@ -70,16 +69,38 @@ class PSK_OT_populate_bone_collection_list(Operator):
         if export_operator is None:
             self.report({'ERROR_INVALID_CONTEXT'}, 'No valid export operator found in context')
             return {'CANCELLED'}
-        input_objects = get_psk_input_objects_for_collection(context.collection)
-        if input_objects.armature_object is None:
-            self.report({'ERROR_INVALID_CONTEXT'}, 'No armature found in collection')
+        try:
+            input_objects = get_psk_input_objects_for_collection(context.collection)
+        except RuntimeError as e:
+            self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
-        populate_bone_collection_list(input_objects.armature_object, export_operator.bone_collection_list)
+        if not input_objects.armature_objects:
+            self.report({'ERROR_INVALID_CONTEXT'}, 'No armature modifiers found on mesh objects')
+            return {'CANCELLED'}
+        populate_bone_collection_list(input_objects.armature_objects, export_operator.bone_collection_list)
+        return {'FINISHED'}
+
+
+class PSK_OT_bone_collection_list_select_all(Operator):
+    bl_idname = 'psk.bone_collection_list_select_all'
+    bl_label = 'Select All'
+    bl_description = 'Select all bone collections'
+    bl_options = {'INTERNAL'}
+
+    is_selected: BoolProperty(default=True)
+
+    def execute(self, context):
+        export_operator = get_collection_export_operator_from_context(context)
+        if export_operator is None:
+            self.report({'ERROR_INVALID_CONTEXT'}, 'No valid export operator found in context')
+            return {'CANCELLED'}
+        for item in export_operator.bone_collection_list:
+            item.is_selected = self.is_selected
         return {'FINISHED'}
 
 
 class PSK_OT_populate_material_name_list(Operator):
-    bl_idname = 'psk_export.populate_material_name_list'
+    bl_idname = 'psk.export_populate_material_name_list'
     bl_label = 'Populate Material Name List'
     bl_description = 'Populate the material name list from the objects that will be used in this export'
     bl_options = {'INTERNAL'}
@@ -92,15 +113,44 @@ class PSK_OT_populate_material_name_list(Operator):
         depsgraph = context.evaluated_depsgraph_get()
         input_objects = get_psk_input_objects_for_collection(context.collection)
         try:
-            populate_material_name_list(depsgraph, [x.obj for x in input_objects.mesh_objects], export_operator.material_name_list)
+            populate_material_name_list(depsgraph, [x.obj for x in input_objects.mesh_dfs_objects], export_operator.material_name_list)
         except RuntimeError as e:
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
         return {'FINISHED'}
 
 
+
+def material_list_names_search_cb(self, context: Context, edit_text: str):
+    for material in bpy.data.materials:
+        yield material.name
+
+
+class PSK_OT_material_list_name_add(Operator):
+    bl_idname = 'psk.export_material_name_list_item_add'
+    bl_label = 'Add Material'
+    bl_description = 'Add a material to the material name list (useful if you want to add a material slot that is not actually used in the mesh)'
+    bl_options = {'INTERNAL'}
+
+    name: StringProperty(search=material_list_names_search_cb, name='Material Name', default='None')
+
+    def invoke(self, context, event):
+        return context.window_manager.invoke_props_dialog(self)
+
+    def execute(self, context):
+        export_operator = get_collection_export_operator_from_context(context)
+        if export_operator is None:
+            self.report({'ERROR_INVALID_CONTEXT'}, 'No valid export operator found in context')
+            return {'CANCELLED'}
+        m = export_operator.material_name_list.add()
+        m.material_name = self.name
+        m.index = len(export_operator.material_name_list) - 1
+        return {'FINISHED'}
+
+
+
 class PSK_OT_material_list_move_up(Operator):
-    bl_idname = 'psk_export.material_list_item_move_up'
+    bl_idname = 'psk.export_material_list_item_move_up'
     bl_label = 'Move Up'
     bl_options = {'INTERNAL'}
     bl_description = 'Move the selected material up one slot'
@@ -118,7 +168,7 @@ class PSK_OT_material_list_move_up(Operator):
 
 
 class PSK_OT_material_list_move_down(Operator):
-    bl_idname = 'psk_export.material_list_item_move_down'
+    bl_idname = 'psk.export_material_list_item_move_down'
     bl_label = 'Move Down'
     bl_options = {'INTERNAL'}
     bl_description = 'Move the selected material down one slot'
@@ -136,7 +186,7 @@ class PSK_OT_material_list_move_down(Operator):
 
 
 class PSK_OT_material_list_name_move_up(Operator):
-    bl_idname = 'psk_export.material_name_list_item_move_up'
+    bl_idname = 'psk.export_material_name_list_item_move_up'
     bl_label = 'Move Up'
     bl_options = {'INTERNAL'}
     bl_description = 'Move the selected material name up one slot'
@@ -159,7 +209,7 @@ class PSK_OT_material_list_name_move_up(Operator):
 
 
 class PSK_OT_material_list_name_move_down(Operator):
-    bl_idname = 'psk_export.material_name_list_item_move_down'
+    bl_idname = 'psk.export_material_name_list_item_move_down'
     bl_label = 'Move Down'
     bl_options = {'INTERNAL'}
     bl_description = 'Move the selected material name down one slot'
@@ -181,13 +231,11 @@ class PSK_OT_material_list_name_move_down(Operator):
         return {'FINISHED'}
 
 
-empty_set = set()
-
-
 def get_sorted_materials_by_names(materials: Iterable[Material], material_names: List[str]) -> List[Material]:
     """
     Sorts the materials by the order of the material names list. Any materials not in the list will be appended to the
     end of the list in the order they are found.
+
     @param materials: A list of materials to sort
     @param material_names: A list of material names to sort by
     @return: A sorted list of materials
@@ -198,28 +246,23 @@ def get_sorted_materials_by_names(materials: Iterable[Material], material_names:
     return materials_in_collection + materials_not_in_collection
 
 
-def get_psk_build_options_from_property_group(mesh_objects: Iterable[Object],  pg: 'PSK_PG_export', depsgraph: Optional[Depsgraph] = None) -> PskBuildOptions:
-    if depsgraph is None:
-        depsgraph = bpy.context.evaluated_depsgraph_get()
-
+def get_psk_build_options_from_property_group(pg: PskExportMixin) -> PskBuildOptions:
     options = PskBuildOptions()
     options.object_eval_state = pg.object_eval_state
     options.export_space = pg.export_space
     options.bone_filter_mode = pg.bone_filter_mode
-    options.bone_collection_indices = [x.index for x in pg.bone_collection_list if x.is_selected]
+    options.bone_collection_indices = [(x.armature_object_name, x.index) for x in pg.bone_collection_list if x.is_selected]
     options.scale = pg.scale
     options.forward_axis = pg.forward_axis
     options.up_axis = pg.up_axis
-
-    # TODO: perhaps move this into the build function and replace the materials list with a material names list.
-    materials = get_materials_for_mesh_objects(depsgraph, mesh_objects)
-    options.materials = get_sorted_materials_by_names(materials, [m.material_name for m in pg.material_name_list])
-
+    options.root_bone_name = pg.root_bone_name
+    options.material_order_mode = pg.material_order_mode
+    options.material_name_list = pg.material_name_list
     return options
 
 
-class PSK_OT_export_collection(Operator, ExportHelper):
-    bl_idname = 'export.psk_collection'
+class PSK_OT_export_collection(Operator, ExportHelper, PskExportMixin):
+    bl_idname = 'psk.export_collection'
     bl_label = 'Export'
     bl_options = {'INTERNAL'}
     filename_ext = '.psk'
@@ -241,13 +284,14 @@ class PSK_OT_export_collection(Operator, ExportHelper):
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
 
-        options = get_psk_build_options_from_property_group([x.obj for x in input_objects.mesh_objects], self)
+        options = get_psk_build_options_from_property_group(self)
+        filepath = str(Path(self.filepath).resolve())
 
         try:
             result = build_psk(context, input_objects, options)
             for warning in result.warnings:
                 self.report({'WARNING'}, warning)
-            write_psk(result.psk, self.filepath)
+            write_psk(result.psk, filepath)
             if len(result.warnings) > 0:
                 self.report({'WARNING'}, f'PSK export successful with {len(result.warnings)} warnings')
             else:
@@ -265,7 +309,7 @@ class PSK_OT_export_collection(Operator, ExportHelper):
         flow.use_property_split = True
         flow.use_property_decorate = False
 
-        # MESH
+        # Mesh
         mesh_header, mesh_panel = layout.panel('Mesh', default_closed=False)
         mesh_header.label(text='Mesh', icon='MESH_DATA')
         if mesh_panel:
@@ -275,30 +319,55 @@ class PSK_OT_export_collection(Operator, ExportHelper):
             flow.prop(self, 'object_eval_state', text='Data')
             flow.prop(self, 'should_exclude_hidden_meshes')
 
-        # BONES
+        # Bones
         bones_header, bones_panel = layout.panel('Bones', default_closed=False)
         bones_header.label(text='Bones', icon='BONE_DATA')
         if bones_panel:
             draw_bone_filter_mode(bones_panel, self, True)
-            if self.bone_filter_mode == 'BONE_COLLECTIONS':
-                bones_panel.operator(PSK_OT_populate_bone_collection_list.bl_idname, icon='FILE_REFRESH')
-                rows = max(3, min(len(self.bone_collection_list), 10))
-                bones_panel.template_list('PSX_UL_bone_collection_list', '', self, 'bone_collection_list', self, 'bone_collection_list_index', rows=rows)
 
-        # MATERIALS
+            if self.bone_filter_mode == 'BONE_COLLECTIONS':
+                row = bones_panel.row()
+                rows = max(3, min(len(self.bone_collection_list), 10))
+                row.template_list('PSX_UL_bone_collection_list', '', self, 'bone_collection_list', self, 'bone_collection_list_index', rows=rows)
+                col = row.column(align=True)
+                col.operator(PSK_OT_bone_collection_list_populate.bl_idname, text='', icon='FILE_REFRESH')
+                col.separator()
+                op = col.operator(PSK_OT_bone_collection_list_select_all.bl_idname, text='', icon='CHECKBOX_HLT')
+                op.is_selected = True
+                op = col.operator(PSK_OT_bone_collection_list_select_all.bl_idname, text='', icon='CHECKBOX_DEHLT')
+                op.is_selected = False
+
+            advanced_bones_header, advanced_bones_panel = bones_panel.panel('Advanced', default_closed=True)
+            advanced_bones_header.label(text='Advanced')
+            if advanced_bones_panel:
+                flow = advanced_bones_panel.grid_flow(row_major=True)
+                flow.use_property_split = True
+                flow.use_property_decorate = False
+                flow.prop(self, 'root_bone_name')
+
+        # Materials
         materials_header, materials_panel = layout.panel('Materials', default_closed=False)
         materials_header.label(text='Materials', icon='MATERIAL')
 
         if materials_panel:
-            materials_panel.operator(PSK_OT_populate_material_name_list.bl_idname, icon='FILE_REFRESH')
-            rows = max(3, min(len(self.material_name_list), 10))
-            row = materials_panel.row()
-            row.template_list('PSK_UL_material_names', '', self, 'material_name_list', self, 'material_name_list_index', rows=rows)
-            col = row.column(align=True)
-            col.operator(PSK_OT_material_list_name_move_up.bl_idname, text='', icon='TRIA_UP')
-            col.operator(PSK_OT_material_list_name_move_down.bl_idname, text='', icon='TRIA_DOWN')
+            flow = materials_panel.grid_flow(row_major=True)
+            flow.use_property_split = True
+            flow.use_property_decorate = False
+            flow.prop(self, 'material_order_mode', text='Material Order')
 
-        # TRANSFORM
+            if self.material_order_mode == 'MANUAL':
+                rows = max(3, min(len(self.material_name_list), 10))
+                row = materials_panel.row()
+                row.template_list('PSK_UL_material_names', '', self, 'material_name_list', self, 'material_name_list_index', rows=rows)
+                col = row.column(align=True)
+                col.operator(PSK_OT_populate_material_name_list.bl_idname, text='', icon='FILE_REFRESH')
+                col.separator()
+                col.operator(PSK_OT_material_list_name_move_up.bl_idname, text='', icon='TRIA_UP')
+                col.operator(PSK_OT_material_list_name_move_down.bl_idname, text='', icon='TRIA_DOWN')
+                col.separator()
+                col.operator(PSK_OT_material_list_name_add.bl_idname, text='', icon='ADD')
+
+        # Transform
         transform_header, transform_panel = layout.panel('Transform', default_closed=False)
         transform_header.label(text='Transform')
         if transform_panel:
@@ -312,15 +381,11 @@ class PSK_OT_export_collection(Operator, ExportHelper):
 
 
 
-add_psk_export_properties(PSK_OT_export_collection)
-
-
-
 class PSK_OT_export(Operator, ExportHelper):
-    bl_idname = 'export.psk'
+    bl_idname = 'psk.export'
     bl_label = 'Export'
     bl_options = {'INTERNAL', 'UNDO'}
-    bl_description = 'Export mesh and armature to PSK'
+    bl_description = 'Export selected meshes to PSK'
     filename_ext = '.psk'
     filter_glob: StringProperty(default='*.psk', options={'HIDDEN'})
     filepath: StringProperty(
@@ -336,18 +401,14 @@ class PSK_OT_export(Operator, ExportHelper):
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
 
-        if len(input_objects.mesh_objects) == 0:
-            self.report({'ERROR_INVALID_CONTEXT'}, 'No mesh objects selected')
-            return {'CANCELLED'}
-
         pg = getattr(context.scene, 'psk_export')
 
-        populate_bone_collection_list(input_objects.armature_object, pg.bone_collection_list)
+        populate_bone_collection_list(input_objects.armature_objects, pg.bone_collection_list)
 
         depsgraph = context.evaluated_depsgraph_get()
 
         try:
-            populate_material_name_list(depsgraph, [x.obj for x in input_objects.mesh_objects], pg.material_name_list)
+            populate_material_name_list(depsgraph, [x.obj for x in input_objects.mesh_dfs_objects], pg.material_name_list)
         except RuntimeError as e:
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
@@ -361,7 +422,7 @@ class PSK_OT_export(Operator, ExportHelper):
 
         pg = getattr(context.scene, 'psk_export')
 
-        # MESH
+        # Mesh
         mesh_header, mesh_panel = layout.panel('Mesh', default_closed=False)
         mesh_header.label(text='Mesh', icon='MESH_DATA')
         if mesh_panel:
@@ -370,7 +431,7 @@ class PSK_OT_export(Operator, ExportHelper):
             flow.use_property_decorate = False
             flow.prop(pg, 'object_eval_state', text='Data')
 
-        # BONES
+        # Bones
         bones_header, bones_panel = layout.panel('Bones', default_closed=False)
         bones_header.label(text='Bones', icon='BONE_DATA')
         if bones_panel:
@@ -379,23 +440,48 @@ class PSK_OT_export(Operator, ExportHelper):
                 row = bones_panel.row()
                 rows = max(3, min(len(pg.bone_collection_list), 10))
                 row.template_list('PSX_UL_bone_collection_list', '', pg, 'bone_collection_list', pg, 'bone_collection_list_index', rows=rows)
+            bones_advanced_header, bones_advanced_panel = bones_panel.panel('Advanced', default_closed=True)
+            bones_advanced_header.label(text='Advanced')
+            if bones_advanced_panel:
+                flow = bones_advanced_panel.grid_flow(row_major=True)
+                flow.use_property_split = True
+                flow.use_property_decorate = False
+                flow.prop(pg, 'root_bone_name')
 
-        # MATERIALS
+        # Materials
         materials_header, materials_panel = layout.panel('Materials', default_closed=False)
         materials_header.label(text='Materials', icon='MATERIAL')
         if materials_panel:
-            row = materials_panel.row()
-            rows = max(3, min(len(pg.bone_collection_list), 10))
-            row.template_list('PSK_UL_material_names', '', pg, 'material_name_list', pg, 'material_name_list_index', rows=rows)
-            col = row.column(align=True)
-            col.operator(PSK_OT_material_list_move_up.bl_idname, text='', icon='TRIA_UP')
-            col.operator(PSK_OT_material_list_move_down.bl_idname, text='', icon='TRIA_DOWN')
+            flow = materials_panel.grid_flow(row_major=True)
+            flow.use_property_split = True
+            flow.use_property_decorate = False
+            flow.prop(pg, 'material_order_mode', text='Material Order')
+
+            if pg.material_order_mode == 'MANUAL':
+                row = materials_panel.row()
+                rows = max(3, min(len(pg.bone_collection_list), 10))
+                row.template_list('PSK_UL_material_names', '', pg, 'material_name_list', pg, 'material_name_list_index', rows=rows)
+                col = row.column(align=True)
+                col.operator(PSK_OT_material_list_move_up.bl_idname, text='', icon='TRIA_UP')
+                col.operator(PSK_OT_material_list_move_down.bl_idname, text='', icon='TRIA_DOWN')
+
+        # Transform
+        transform_header, transform_panel = layout.panel('Transform', default_closed=False)
+        transform_header.label(text='Transform')
+        if transform_panel:
+            flow = transform_panel.grid_flow(row_major=True)
+            flow.use_property_split = True
+            flow.use_property_decorate = False
+            flow.prop(pg, 'export_space')
+            flow.prop(pg, 'scale')
+            flow.prop(pg, 'forward_axis')
+            flow.prop(pg, 'up_axis')
 
     def execute(self, context):
         pg = getattr(context.scene, 'psk_export')
 
         input_objects = get_psk_input_objects_for_context(context)
-        options = get_psk_build_options_from_property_group([x.obj for x in input_objects.mesh_objects], pg)
+        options = get_psk_build_options_from_property_group(pg)
 
         try:
             result = build_psk(context, input_objects, options)
@@ -418,8 +504,10 @@ classes = (
     PSK_OT_material_list_move_down,
     PSK_OT_export,
     PSK_OT_export_collection,
-    PSK_OT_populate_bone_collection_list,
+    PSK_OT_bone_collection_list_populate,
+    PSK_OT_bone_collection_list_select_all,
     PSK_OT_populate_material_name_list,
     PSK_OT_material_list_name_move_up,
     PSK_OT_material_list_name_move_down,
+    PSK_OT_material_list_name_add,
 )

io_scene_psk_psa/psk/export/properties.py

@@ -1,40 +1,23 @@
-from bpy.props import EnumProperty, CollectionProperty, IntProperty, PointerProperty, FloatProperty, StringProperty, \
-    BoolProperty
-from bpy.types import PropertyGroup, Material
-
-from ...shared.data import bone_filter_mode_items
-from ...shared.types import PSX_PG_bone_collection_list_item
-
-empty_set = set()
+from bpy.props import (
+    BoolProperty,
+    CollectionProperty,
+    EnumProperty,
+    FloatProperty,
+    IntProperty,
+    PointerProperty,
+    StringProperty,
+)
+from bpy.types import Material, PropertyGroup
+from ...shared.types import ExportSpaceMixin, ForwardUpAxisMixin, PsxBoneExportMixin
 
 object_eval_state_items = (
     ('EVALUATED', 'Evaluated', 'Use data from fully evaluated object'),
     ('ORIGINAL', 'Original', 'Use data from original object with no modifiers applied'),
 )
 
-export_space_items = [
-    ('WORLD', 'World', 'Export in world space'),
-    ('ARMATURE', 'Armature', 'Export in armature space'),
-]
-
-
-axis_identifiers = ('X', 'Y', 'Z', '-X', '-Y', '-Z')
-forward_items = (
-    ('X', 'X Forward', ''),
-    ('Y', 'Y Forward', ''),
-    ('Z', 'Z Forward', ''),
-    ('-X', '-X Forward', ''),
-    ('-Y', '-Y Forward', ''),
-    ('-Z', '-Z Forward', ''),
-)
-
-up_items = (
-    ('X', 'X Up', ''),
-    ('Y', 'Y Up', ''),
-    ('Z', 'Z Up', ''),
-    ('-X', '-X Up', ''),
-    ('-Y', '-Y Up', ''),
-    ('-Z', '-Z Up', ''),
+material_order_mode_items = (
+    ('AUTOMATIC', 'Automatic', 'Automatically order the materials'),
+    ('MANUAL', 'Manual', 'Manually arrange the materials'),
 )
 
 class PSK_PG_material_list_item(PropertyGroup):
@@ -46,79 +29,38 @@ class PSK_PG_material_name_list_item(PropertyGroup):
     index: IntProperty()
 
 
+class PskExportMixin(ExportSpaceMixin, ForwardUpAxisMixin, PsxBoneExportMixin):
+    object_eval_state: EnumProperty(
+        items=object_eval_state_items,
+        name='Object Evaluation State',
+        default='EVALUATED'
+    )
+    should_exclude_hidden_meshes: BoolProperty(
+        default=False,
+        name='Visible Only',
+        description='Export only visible meshes'
+    )
+    scale: FloatProperty(
+        name='Scale',
+        default=1.0,
+        description='Scale factor to apply to the exported mesh and armature',
+        min=0.0001,
+        soft_max=100.0
+    )
+    material_order_mode: EnumProperty(
+        name='Material Order',
+        description='The order in which to export the materials',
+        items=material_order_mode_items,
+        default='AUTOMATIC'
+    )
+    material_name_list: CollectionProperty(type=PSK_PG_material_name_list_item)
+    material_name_list_index: IntProperty(default=0)
 
 
-def forward_axis_update(self, _context):
-    if self.forward_axis == self.up_axis:
-        # Automatically set the up axis to the next available axis
-        self.up_axis = next((axis for axis in axis_identifiers if axis != self.forward_axis), 'Z')
-
-
-def up_axis_update(self, _context):
-    if self.up_axis == self.forward_axis:
-        # Automatically set the forward axis to the next available axis
-        self.forward_axis = next((axis for axis in axis_identifiers if axis != self.up_axis), 'X')
-
-
-
-# In order to share the same properties between the PSA and PSK export properties, we need to define the properties in a
-# separate function and then apply them to the classes. This is because the collection exporter cannot have
-# PointerProperties, so we must effectively duplicate the storage of the properties.
-def add_psk_export_properties(cls):
-        cls.__annotations__['object_eval_state'] = EnumProperty(
-            items=object_eval_state_items,
-            name='Object Evaluation State',
-            default='EVALUATED'
-        )
-        cls.__annotations__['should_exclude_hidden_meshes'] = BoolProperty(
-            default=False,
-            name='Visible Only',
-            description='Export only visible meshes'
-        )
-        cls.__annotations__['scale'] = FloatProperty(
-            name='Scale',
-            default=1.0,
-            description='Scale factor to apply to the exported mesh and armature',
-            min=0.0001,
-            soft_max=100.0
-        )
-        cls.__annotations__['export_space'] = EnumProperty(
-            name='Export Space',
-            description='Space to export the mesh in',
-            items=export_space_items,
-            default='WORLD'
-        )
-        cls.__annotations__['bone_filter_mode'] = EnumProperty(
-            name='Bone Filter',
-            options=empty_set,
-            description='',
-            items=bone_filter_mode_items,
-        )
-        cls.__annotations__['bone_collection_list'] = CollectionProperty(type=PSX_PG_bone_collection_list_item)
-        cls.__annotations__['bone_collection_list_index'] = IntProperty(default=0)
-        cls.__annotations__['forward_axis'] = EnumProperty(
-            name='Forward',
-            items=forward_items,
-            default='X',
-            update=forward_axis_update
-        )
-        cls.__annotations__['up_axis'] = EnumProperty(
-            name='Up',
-            items=up_items,
-            default='Z',
-            update=up_axis_update
-        )
-        cls.__annotations__['material_name_list'] = CollectionProperty(type=PSK_PG_material_name_list_item)
-        cls.__annotations__['material_name_list_index'] = IntProperty(default=0)
-
-
-class PSK_PG_export(PropertyGroup):
+class PSK_PG_export(PropertyGroup, PskExportMixin):
     pass
 
 
-add_psk_export_properties(PSK_PG_export)
-
-
 classes = (
     PSK_PG_material_list_item,
     PSK_PG_material_name_list_item,

io_scene_psk_psa/psk/export/ui.py

@@ -6,7 +6,8 @@ class PSK_UL_material_names(UIList):
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
         row = layout.row()
         material = bpy.data.materials.get(item.material_name, None)
-        row.prop(item, 'material_name', text='', emboss=False, icon_value=layout.icon(material) if material else 0)
+        icon_value = layout.icon(material) if material else 0
+        row.prop(item, 'material_name', text='', emboss=False, icon_value=icon_value, icon='BLANK1' if icon_value == 0 else 'NONE')
 
 
 classes = (

io_scene_psk_psa/psk/import_/operators.py

@@ -1,30 +1,82 @@
 import os
-import sys
+from pathlib import Path
 
-from bpy.props import StringProperty, BoolProperty, EnumProperty, FloatProperty
-from bpy.types import Operator, FileHandler, Context
+from bpy.props import CollectionProperty, StringProperty
+from bpy.types import Context, FileHandler, Operator, OperatorFileListElement, UILayout
 from bpy_extras.io_utils import ImportHelper
 
 from ..importer import PskImportOptions, import_psk
+from ..properties import PskImportMixin
 from ..reader import read_psk
 
-empty_set = set()
+def get_psk_import_options_from_properties(property_group: PskImportMixin):
+    options = PskImportOptions()
+    options.should_import_mesh = property_group.should_import_mesh
+    options.should_import_extra_uvs = property_group.should_import_extra_uvs
+    options.should_import_vertex_colors = property_group.should_import_vertex_colors
+    options.should_import_vertex_normals = property_group.should_import_vertex_normals
+    options.vertex_color_space = property_group.vertex_color_space
+    options.should_import_armature = property_group.should_import_armature
+    options.bone_length = property_group.bone_length
+    options.should_import_materials = property_group.should_import_materials
+    options.should_import_shape_keys = property_group.should_import_shape_keys
+    options.scale = property_group.scale
+
+    if property_group.bdk_repository_id:
+        options.bdk_repository_id = property_group.bdk_repository_id
+
+    return options
 
 
-class PSK_FH_import(FileHandler):
-    bl_idname = 'PSK_FH_import'
-    bl_label = 'Unreal PSK'
-    bl_import_operator = 'import_scene.psk'
-    bl_export_operator = 'export.psk_collection'
-    bl_file_extensions = '.psk;.pskx'
+def psk_import_draw(layout: UILayout, props: PskImportMixin):
+    row = layout.row()
 
-    @classmethod
-    def poll_drop(cls, context: Context):
-        return context.area and context.area.type == 'VIEW_3D'
+    col = row.column()
+    col.use_property_split = True
+    col.use_property_decorate = False
+    col.prop(props, 'components')
+
+    if props.should_import_mesh:
+        mesh_header, mesh_panel = layout.panel('mesh_panel_id', default_closed=False)
+        mesh_header.label(text='Mesh', icon='MESH_DATA')
+
+        if mesh_panel:
+            row = mesh_panel.row()
+            col = row.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(props, 'should_import_extra_uvs', text='Extra UVs')
+            col.prop(props, 'should_import_materials', text='Materials')
+            col.prop(props, 'should_import_vertex_colors', text='Vertex Colors')
+            if props.should_import_vertex_colors:
+                col.prop(props, 'vertex_color_space')
+            col.separator()
+            col.prop(props, 'should_import_vertex_normals', text='Vertex Normals')
+            col.prop(props, 'should_import_shape_keys', text='Shape Keys')
+
+    if props.should_import_armature:
+        armature_header, armature_panel = layout.panel('armature_panel_id', default_closed=False)
+        armature_header.label(text='Armature', icon='OUTLINER_DATA_ARMATURE')
+
+        if armature_panel:
+            row = armature_panel.row()
+            col = row.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(props, 'bone_length')
+
+    transform_header, transform_panel = layout.panel('transform_panel_id', default_closed=False)
+    transform_header.label(text='Transform')
+    if transform_panel:
+        row = transform_panel.row()
+        col = row.column()
+        col.use_property_split = True
+        col.use_property_decorate = False
+        col.prop(props, 'scale')
 
 
-class PSK_OT_import(Operator, ImportHelper):
-    bl_idname = 'import_scene.psk'
+class PSK_OT_import(Operator, ImportHelper, PskImportMixin):
+    bl_idname = 'psk.import_file'
     bl_label = 'Import'
     bl_options = {'INTERNAL', 'UNDO', 'PRESET'}
     bl_description = 'Import a PSK file'
@@ -36,152 +88,91 @@ class PSK_OT_import(Operator, ImportHelper):
         maxlen=1024,
         default='')
 
-    should_import_vertex_colors: BoolProperty(
-        default=True,
-        options=empty_set,
-        name='Import Vertex Colors',
-        description='Import vertex colors, if available'
-    )
-    vertex_color_space: EnumProperty(
-        name='Vertex Color Space',
-        options=empty_set,
-        description='The source vertex color space',
-        default='SRGBA',
-        items=(
-            ('LINEAR', 'Linear', ''),
-            ('SRGBA', 'sRGBA', ''),
-        )
-    )
-    should_import_vertex_normals: BoolProperty(
-        default=True,
-        name='Import Vertex Normals',
-        options=empty_set,
-        description='Import vertex normals, if available'
-    )
-    should_import_extra_uvs: BoolProperty(
-        default=True,
-        name='Import Extra UVs',
-        options=empty_set,
-        description='Import extra UV maps, if available'
-    )
-    should_import_mesh: BoolProperty(
-        default=True,
-        name='Import Mesh',
-        options=empty_set,
-        description='Import mesh'
-    )
-    should_import_materials: BoolProperty(
-        default=True,
-        name='Import Materials',
-        options=empty_set,
-    )
-    should_import_skeleton: BoolProperty(
-        default=True,
-        name='Import Skeleton',
-        options=empty_set,
-        description='Import skeleton'
-    )
-    bone_length: FloatProperty(
-        default=1.0,
-        min=sys.float_info.epsilon,
-        step=100,
-        soft_min=1.0,
-        name='Bone Length',
-        options=empty_set,
-        subtype='DISTANCE',
-        description='Length of the bones'
-    )
-    should_import_shape_keys: BoolProperty(
-        default=True,
-        name='Import Shape Keys',
-        options=empty_set,
-        description='Import shape keys, if available'
-    )
-    scale: FloatProperty(
-        name='Scale',
-        default=1.0,
-        soft_min=0.0,
-    )
-    bdk_repository_id: StringProperty(
-        name='BDK Repository ID',
-        default='',
-        options=empty_set,
-        description='The ID of the BDK repository to use for loading materials'
-    )
-
     def execute(self, context):
-        psk = read_psk(self.filepath)
-
-        options = PskImportOptions()
-        options.name = os.path.splitext(os.path.basename(self.filepath))[0]
-        options.should_import_mesh = self.should_import_mesh
-        options.should_import_extra_uvs = self.should_import_extra_uvs
-        options.should_import_vertex_colors = self.should_import_vertex_colors
-        options.should_import_vertex_normals = self.should_import_vertex_normals
-        options.vertex_color_space = self.vertex_color_space
-        options.should_import_skeleton = self.should_import_skeleton
-        options.bone_length = self.bone_length
-        options.should_import_materials = self.should_import_materials
-        options.should_import_shape_keys = self.should_import_shape_keys
-        options.scale = self.scale
-
-        if self.bdk_repository_id:
-            options.bdk_repository_id = self.bdk_repository_id
-
-        if not options.should_import_mesh and not options.should_import_skeleton:
-            self.report({'ERROR'}, 'Nothing to import')
+        try:
+            psk = read_psk(self.filepath)
+        except OSError as e:
+            self.report({'ERROR'}, f'Failed to read "{self.filepath}". The file may be corrupted or not a valid PSK file: {e}')
             return {'CANCELLED'}
 
-        result = import_psk(psk, context, options)
+        name = os.path.splitext(os.path.basename(self.filepath))[0]
+        options = get_psk_import_options_from_properties(self)
+        result = import_psk(psk, context, name, options)
 
         if len(result.warnings):
-            message = f'PSK imported with {len(result.warnings)} warning(s)\n'
+            message = f'PSK imported as "{result.root_object.name}" with {len(result.warnings)} warning(s)\n'
             message += '\n'.join(result.warnings)
             self.report({'WARNING'}, message)
         else:
-            self.report({'INFO'}, f'PSK imported ({options.name})')
+            self.report({'INFO'}, f'PSK imported as "{result.root_object.name}"')
 
         return {'FINISHED'}
 
     def draw(self, context):
-        layout = self.layout
+        psk_import_draw(self.layout, self)
 
-        row = layout.row()
 
-        col = row.column()
-        col.use_property_split = True
-        col.use_property_decorate = False
-        col.prop(self, 'scale')
-        col.prop(self, 'export_space')
+class PSK_OT_import_drag_and_drop(Operator, PskImportMixin):
+    bl_idname = 'psk.import_drag_and_drop'
+    bl_label = 'Import PSK'
+    bl_options = {'INTERNAL', 'UNDO', 'PRESET'}
+    bl_description = 'Import PSK files by dragging and dropping them onto the 3D view'
 
-        mesh_header, mesh_panel = layout.panel('mesh_panel_id', default_closed=False)
-        mesh_header.prop(self, 'should_import_mesh')
+    directory: StringProperty(subtype='FILE_PATH', options={'SKIP_SAVE', 'HIDDEN'})
+    files: CollectionProperty(type=OperatorFileListElement, options={'SKIP_SAVE', 'HIDDEN'})
 
-        if mesh_panel and self.should_import_mesh:
-            row = mesh_panel.row()
-            col = row.column()
-            col.use_property_split = True
-            col.use_property_decorate = False
-            col.prop(self, 'should_import_materials', text='Materials')
-            col.prop(self, 'should_import_vertex_normals', text='Vertex Normals')
-            col.prop(self, 'should_import_extra_uvs', text='Extra UVs')
-            col.prop(self, 'should_import_vertex_colors', text='Vertex Colors')
-            if self.should_import_vertex_colors:
-                col.prop(self, 'vertex_color_space')
-            col.prop(self, 'should_import_shape_keys', text='Shape Keys')
+    @classmethod
+    def poll(cls, context):
+        return context.area and context.area.type == 'VIEW_3D'
 
-        skeleton_header, skeleton_panel = layout.panel('skeleton_panel_id', default_closed=False)
-        skeleton_header.prop(self, 'should_import_skeleton')
+    def draw(self, context):
+        psk_import_draw(self.layout, self)
 
-        if skeleton_panel and self.should_import_skeleton:
-            row = skeleton_panel.row()
-            col = row.column()
-            col.use_property_split = True
-            col.use_property_decorate = False
-            col.prop(self, 'bone_length')
+    def invoke(self, context, event):
+        context.window_manager.invoke_props_dialog(self)
+        return {'RUNNING_MODAL'}
+
+    def execute(self, context):
+        warning_count = 0
+
+        options = get_psk_import_options_from_properties(self)
+
+        for file in self.files:
+            filepath = Path(self.directory) / file.name
+            try:
+                psk = read_psk(filepath)
+            except OSError as e:
+                self.report({'ERROR'}, f'Failed to read "{filepath}". The file may be corrupted or not a valid PSK file: {e}')
+                return {'CANCELLED'}
+
+            name = os.path.splitext(file.name)[0]
+            result = import_psk(psk, context, name, options)
+            if result.warnings:
+                warning_count += len(result.warnings)
+
+        if warning_count > 0:
+            self.report({'WARNING'}, f'Imported {len(self.files)} PSK file(s) with {warning_count} warning(s)')
+        else:
+            self.report({'INFO'}, f'Imported {len(self.files)} PSK file(s)')
+
+        return {'FINISHED'}
+
+
+# TODO: move to another file
+class PSK_FH_import(FileHandler):
+    bl_idname = 'PSK_FH_import'
+    bl_label = 'Unreal PSK'
+    bl_import_operator = PSK_OT_import_drag_and_drop.bl_idname
+    bl_export_operator = 'psk.export_collection'
+    bl_file_extensions = '.psk;.pskx'
+
+    @classmethod
+    def poll_drop(cls, context: Context):
+        return context.area and context.area.type == 'VIEW_3D'
 
 
 classes = (
     PSK_OT_import,
+    PSK_OT_import_drag_and_drop,
     PSK_FH_import,
 )

io_scene_psk_psa/psk/importer.py

@@ -1,26 +1,26 @@
-from typing import Optional, List
-
 import bmesh
 import bpy
 import numpy as np
-from bpy.types import VertexGroup
-from mathutils import Quaternion, Vector, Matrix
+
+from bpy.types import Context, Object, VertexGroup
+from mathutils import Matrix, Quaternion, Vector
+from typing import List, Optional
 
 from .data import Psk
 from .properties import poly_flags_to_triangle_type_and_bit_flags
-from ..shared.helpers import rgb_to_srgb, is_bdk_addon_loaded
+from ..shared.data import PsxBone
+from ..shared.helpers import is_bdk_addon_loaded, rgb_to_srgb
 
 
 class PskImportOptions:
     def __init__(self):
-        self.name = ''
         self.should_import_mesh = True
         self.should_reuse_materials = True
         self.should_import_vertex_colors = True
         self.vertex_color_space = 'SRGB'
         self.should_import_vertex_normals = True
         self.should_import_extra_uvs = True
-        self.should_import_skeleton = True
+        self.should_import_armature = True
         self.should_import_shape_keys = True
         self.bone_length = 1.0
         self.should_import_materials = True
@@ -29,12 +29,12 @@ class PskImportOptions:
 
 
 class ImportBone:
-    '''
+    """
     Intermediate bone type for the purpose of construction.
-    '''
-    def __init__(self, index: int, psk_bone: Psk.Bone):
+    """
+    def __init__(self, index: int, psk_bone: PsxBone):
         self.index: int = index
-        self.psk_bone: Psk.Bone = psk_bone
+        self.psk_bone: PsxBone = psk_bone
         self.parent: Optional[ImportBone] = None
         self.local_rotation: Quaternion = Quaternion()
         self.local_translation: Vector = Vector()
@@ -49,17 +49,23 @@ class ImportBone:
 class PskImportResult:
     def __init__(self):
         self.warnings: List[str] = []
+        self.armature_object: Optional[Object] = None
+        self.mesh_object: Optional[Object] = None
+
+    @property
+    def root_object(self) -> Object:
+        return self.armature_object if self.armature_object is not None else self.mesh_object
 
 
-def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
+def import_psk(psk: Psk, context: Context, name: str, options: PskImportOptions) -> PskImportResult:
     result = PskImportResult()
     armature_object = None
     mesh_object = None
 
-    if options.should_import_skeleton:
-        # ARMATURE
-        armature_data = bpy.data.armatures.new(options.name)
-        armature_object = bpy.data.objects.new(options.name, armature_data)
+    if options.should_import_armature:
+        # Armature
+        armature_data = bpy.data.armatures.new(name)
+        armature_object = bpy.data.objects.new(name, armature_data)
         armature_object.show_in_front = True
 
         context.scene.collection.objects.link(armature_object)
@@ -114,16 +120,17 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             edit_bone_matrix.translation = import_bone.world_matrix.translation
             edit_bone.matrix = edit_bone_matrix
 
-    # MESH
+    # Mesh
     if options.should_import_mesh:
-        mesh_data = bpy.data.meshes.new(options.name)
-        mesh_object = bpy.data.objects.new(options.name, mesh_data)
+        mesh_data = bpy.data.meshes.new(name)
+        mesh_object = bpy.data.objects.new(name, mesh_data)
 
-        # MATERIALS
+        # Materials
         if options.should_import_materials:
             for material_index, psk_material in enumerate(psk.materials):
                 material_name = psk_material.name.decode('utf-8')
                 material = None
+
                 if options.should_reuse_materials and material_name in bpy.data.materials:
                     # Material already exists, just re-use it.
                     material = bpy.data.materials[material_name]
@@ -134,24 +141,26 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
                     repository_id = options.bdk_repository_id if options.bdk_repository_id is not None else ''
                     if material_reference and bpy.ops.bdk.link_material(reference=material_reference, repository_id=repository_id) == {'FINISHED'}:
                         material = bpy.data.materials[material_name]
-                else:
-                    # Just create a blank material.
+                
+                if material is None:
+                    # Material was unable to be loaded, so just create a blank material.
                     material = bpy.data.materials.new(material_name)
                     mesh_triangle_type, mesh_triangle_bit_flags = poly_flags_to_triangle_type_and_bit_flags(psk_material.poly_flags)
                     material.psk.mesh_triangle_type = mesh_triangle_type
                     material.psk.mesh_triangle_bit_flags = mesh_triangle_bit_flags
                     material.use_nodes = True
+                
                 mesh_data.materials.append(material)
 
         bm = bmesh.new()
 
-        # VERTICES
+        # Vertices
         for point in psk.points:
             bm.verts.new(tuple(point))
 
         bm.verts.ensure_lookup_table()
 
-        # FACES
+        # Faces
         invalid_face_indices = set()
         for face_index, face in enumerate(psk.faces):
             point_indices = map(lambda i: psk.wedges[i].point_index, reversed(face.wedge_indices))
@@ -171,7 +180,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
 
         bm.to_mesh(mesh_data)
 
-        # TEXTURE COORDINATES
+        # Texture Coordinates
         uv_layer_data_index = 0
         uv_layer = mesh_data.uv_layers.new(name='UVMap')
         for face_index, face in enumerate(psk.faces):
@@ -182,7 +191,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
                 uv_layer.data[uv_layer_data_index].uv = wedge.u, 1.0 - wedge.v
                 uv_layer_data_index += 1
 
-        # EXTRA UVS
+        # Extra UVs
         if psk.has_extra_uvs and options.should_import_extra_uvs:
             extra_uv_channel_count = int(len(psk.extra_uvs) / len(psk.wedges))
             wedge_index_offset = 0
@@ -198,18 +207,15 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
                         uv_layer_data_index += 1
                 wedge_index_offset += len(psk.wedges)
 
-        # VERTEX COLORS
+        # Vertex Colors
         if psk.has_vertex_colors and options.should_import_vertex_colors:
             # Convert vertex colors to sRGB if necessary.
             psk_vertex_colors = np.zeros((len(psk.vertex_colors), 4))
             for vertex_color_index in range(len(psk.vertex_colors)):
                 psk_vertex_colors[vertex_color_index,:] = psk.vertex_colors[vertex_color_index].normalized()
-            match options.vertex_color_space:
-                case 'SRGBA':
-                    for i in range(psk_vertex_colors.shape[0]):
-                        psk_vertex_colors[i, :3] = tuple(map(lambda x: rgb_to_srgb(x), psk_vertex_colors[i, :3]))
-                case _:
-                    pass
+            if options.vertex_color_space == 'SRGBA':
+                for i in range(psk_vertex_colors.shape[0]):
+                    psk_vertex_colors[i, :3] = tuple(map(lambda x: rgb_to_srgb(x), psk_vertex_colors[i, :3]))
 
             # Map the PSK vertex colors to the face corners.
             face_count = len(psk.faces) - len(invalid_face_indices)
@@ -226,7 +232,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             face_corner_color_attribute = mesh_data.attributes.new(name='VERTEXCOLOR', type='FLOAT_COLOR', domain='CORNER')
             face_corner_color_attribute.data.foreach_set('color', face_corner_colors.flatten())
 
-        # VERTEX NORMALS
+        # Vertex Normals
         if psk.has_vertex_normals and options.should_import_vertex_normals:
             mesh_data.polygons.foreach_set('use_smooth', [True] * len(mesh_data.polygons))
             normals = []
@@ -239,7 +245,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
         bm.normal_update()
         bm.free()
 
-        # WEIGHTS
+        # Weights
         # Get a list of all bones that have weights associated with them.
         vertex_group_bone_indices = set(map(lambda weight: weight.bone_index, psk.weights))
         vertex_groups: List[Optional[VertexGroup]] = [None] * len(psk.bones)
@@ -249,7 +255,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
         for weight in psk.weights:
             vertex_groups[weight.bone_index].add((weight.point_index,), weight.weight, 'ADD')
 
-        # MORPHS (SHAPE KEYS)
+        # Morphs (Shape Keys)
         if options.should_import_shape_keys:
             morph_data_iterator = iter(psk.morph_data)
 
@@ -267,12 +273,12 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
         context.scene.collection.objects.link(mesh_object)
 
         # Add armature modifier to our mesh object.
-        if options.should_import_skeleton:
+        if options.should_import_armature:
             armature_modifier = mesh_object.modifiers.new(name='Armature', type='ARMATURE')
             armature_modifier.object = armature_object
             mesh_object.parent = armature_object
 
-    root_object = armature_object if options.should_import_skeleton else mesh_object
+    root_object = armature_object if options.should_import_armature else mesh_object
     root_object.scale = (options.scale, options.scale, options.scale)
 
     try:
@@ -280,4 +286,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
     except:
         pass
 
+    result.armature_object = armature_object
+    result.mesh_object = mesh_object
+
     return result

io_scene_psk_psa/psk/properties.py

@@ -1,4 +1,6 @@
-from bpy.props import EnumProperty
+import sys
+
+from bpy.props import BoolProperty, EnumProperty, FloatProperty, StringProperty
 from bpy.types import PropertyGroup
 
 mesh_triangle_types_items = (
@@ -43,6 +45,96 @@ def poly_flags_to_triangle_type_and_bit_flags(poly_flags: int) -> (str, set[str]
     return triangle_type, triangle_bit_flags
 
 
+def should_import_mesh_get(self):
+    return self.components in {'ALL', 'MESH'}
+
+
+def should_import_skleton_get(self):
+    return self.components in {'ALL', 'ARMATURE'}
+
+
+class PskImportMixin:
+    should_import_vertex_colors: BoolProperty(
+        default=True,
+        options=set(),
+        name='Import Vertex Colors',
+        description='Import vertex colors, if available'
+    )
+    vertex_color_space: EnumProperty(
+        name='Vertex Color Space',
+        options=set(),
+        description='The source vertex color space',
+        default='SRGBA',
+        items=(
+            ('LINEAR', 'Linear', ''),
+            ('SRGBA', 'sRGBA', ''),
+        )
+    )
+    should_import_vertex_normals: BoolProperty(
+        default=True,
+        name='Import Vertex Normals',
+        options=set(),
+        description='Import vertex normals, if available.\n\nThis is only supported for PSKX files'
+    )
+    should_import_extra_uvs: BoolProperty(
+        default=True,
+        name='Import Extra UVs',
+        options=set(),
+        description='Import extra UV maps, if available'
+    )
+    components: EnumProperty(
+        name='Components',
+        options=set(),
+        description='Which components to import',
+        items=(
+            ('ALL', 'Mesh & Armature', 'Import mesh and armature'),
+            ('MESH', 'Mesh Only', 'Import mesh only'),
+            ('ARMATURE', 'Armature Only', 'Import armature only'),
+        ),
+        default='ALL'
+    )
+    should_import_mesh: BoolProperty(
+        name='Import Mesh',
+        get=should_import_mesh_get,
+    )
+    should_import_materials: BoolProperty(
+        default=True,
+        name='Import Materials',
+        options=set(),
+    )
+    should_import_armature: BoolProperty(
+        name='Import Skeleton',
+        get=should_import_skleton_get,
+    )
+    bone_length: FloatProperty(
+        default=1.0,
+        min=sys.float_info.epsilon,
+        step=100,
+        soft_min=1.0,
+        name='Bone Length',
+        options=set(),
+        subtype='DISTANCE',
+        description='Length of the bones'
+    )
+    should_import_shape_keys: BoolProperty(
+        default=True,
+        name='Import Shape Keys',
+        options=set(),
+        description='Import shape keys, if available.\n\nThis is only supported for PSKX files'
+    )
+    scale: FloatProperty(
+        name='Scale',
+        default=1.0,
+        soft_min=0.0,
+    )
+    bdk_repository_id: StringProperty(
+        name='BDK Repository ID',
+        default='',
+        options=set(),
+        description='The ID of the BDK repository to use for loading materials'
+    )
+
+
 classes = (
     PSX_PG_material,
 )

io_scene_psk_psa/psk/reader.py

@@ -3,8 +3,9 @@ import os
 import re
 import warnings
 from pathlib import Path
-
-from .data import *
+from typing import List
+from ..shared.data import Section
+from .data import Color, Psk, PsxBone, Vector2, Vector3
 
 
 def _read_types(fp, data_class, section: Section, data):
@@ -28,7 +29,6 @@ def _read_material_references(path: str) -> List[str]:
 
 
 def read_psk(path: str) -> Psk:
-
     psk = Psk()
 
     # Read the PSK file sections.
@@ -53,7 +53,7 @@ def read_psk(path: str) -> Psk:
                 case b'MATT0000':
                     _read_types(fp, Psk.Material, section, psk.materials)
                 case b'REFSKELT':
-                    _read_types(fp, Psk.Bone, section, psk.bones)
+                    _read_types(fp, PsxBone, section, psk.bones)
                 case b'RAWWEIGHTS':
                     _read_types(fp, Psk.Weight, section, psk.weights)
                 case b'FACE3200':
@@ -74,20 +74,20 @@ def read_psk(path: str) -> Psk:
                         fp.seek(section.data_size * section.data_count, os.SEEK_CUR)
                         warnings.warn(f'Unrecognized section "{section.name} at position {fp.tell():15}"')
 
-    '''
+    """
     UEViewer exports a sidecar file (*.props.txt) with fully-qualified reference paths for each material
     (e.g., Texture'Package.Group.Object').
-    '''
+    """
     psk.material_references = _read_material_references(path)
 
-    '''
+    """
     Tools like UEViewer and CUE4Parse write the point index as a 32-bit integer, exploiting the fact that due to struct
     alignment, there were 16-bits of padding following the original 16-bit point index in the wedge struct.
     However, this breaks compatibility with PSK files that were created with older tools that treated the
     point index as a 16-bit integer and might have junk data written to the padding bits.
     To work around this, we check if each point is still addressable using a 16-bit index, and if it is, assume the
     point index is a 16-bit integer and truncate the high bits.
-    '''
+    """
     if len(psk.points) <= 65536:
         for wedge in psk.wedges:
             wedge.point_index &= 0xFFFF

io_scene_psk_psa/psk/writer.py

@@ -3,7 +3,7 @@ from ctypes import Structure, sizeof
 from typing import Type
 
 from .data import Psk
-from ..shared.data import Section, Vector3
+from ..shared.data import PsxBone, Section, Vector3
 
 MAX_WEDGE_COUNT = 65536
 MAX_POINT_COUNT = 4294967296
@@ -32,27 +32,30 @@ def write_psk(psk: Psk, path: str):
         raise RuntimeError(f'Number of materials ({len(psk.materials)}) exceeds limit of {MAX_MATERIAL_COUNT}')
     if len(psk.bones) > MAX_BONE_COUNT:
         raise RuntimeError(f'Number of bones ({len(psk.bones)}) exceeds limit of {MAX_BONE_COUNT}')
-    elif len(psk.bones) == 0:
+    if len(psk.bones) == 0:
         raise RuntimeError(f'At least one bone must be marked for export')
 
     # Make the directory for the file if it doesn't exist.
     os.makedirs(os.path.dirname(path), exist_ok=True)
 
-    with open(path, 'wb') as fp:
-        _write_section(fp, b'ACTRHEAD')
-        _write_section(fp, b'PNTS0000', Vector3, psk.points)
+    try:
+        with open(path, 'wb') as fp:
+            _write_section(fp, b'ACTRHEAD')
+            _write_section(fp, b'PNTS0000', Vector3, psk.points)
 
-        wedges = []
-        for index, w in enumerate(psk.wedges):
-            wedge = Psk.Wedge16()
-            wedge.material_index = w.material_index
-            wedge.u = w.u
-            wedge.v = w.v
-            wedge.point_index = w.point_index
-            wedges.append(wedge)
+            wedges = []
+            for index, w in enumerate(psk.wedges):
+                wedge = Psk.Wedge16()
+                wedge.material_index = w.material_index
+                wedge.u = w.u
+                wedge.v = w.v
+                wedge.point_index = w.point_index
+                wedges.append(wedge)
 
-        _write_section(fp, b'VTXW0000', Psk.Wedge16, wedges)
-        _write_section(fp, b'FACE0000', Psk.Face, psk.faces)
-        _write_section(fp, b'MATT0000', Psk.Material, psk.materials)
-        _write_section(fp, b'REFSKELT', Psk.Bone, psk.bones)
-        _write_section(fp, b'RAWWEIGHTS', Psk.Weight, psk.weights)
+            _write_section(fp, b'VTXW0000', Psk.Wedge16, wedges)
+            _write_section(fp, b'FACE0000', Psk.Face, psk.faces)
+            _write_section(fp, b'MATT0000', Psk.Material, psk.materials)
+            _write_section(fp, b'REFSKELT', PsxBone, psk.bones)
+            _write_section(fp, b'RAWWEIGHTS', Psk.Weight, psk.weights)
+    except PermissionError as e:
+        raise RuntimeError(f'The current user "{os.getlogin()}" does not have permission to write to "{path}"') from e

io_scene_psk_psa/shared/data.py

@@ -1,4 +1,4 @@
-from ctypes import *
+from ctypes import Structure, c_char, c_int32, c_float, c_ubyte
 from typing import Tuple
 
 
@@ -82,6 +82,19 @@ class Quaternion(Structure):
         return Quaternion(0, 0, 0, 1)
 
 
+class PsxBone(Structure):
+    _fields_ = [
+        ('name', c_char * 64),
+        ('flags', c_int32),
+        ('children_count', c_int32),
+        ('parent_index', c_int32),
+        ('rotation', Quaternion),
+        ('location', Vector3),
+        ('length', c_float),
+        ('size', Vector3)
+    ]
+
+
 class Section(Structure):
     _fields_ = [
         ('name', c_char * 20),
@@ -93,9 +106,3 @@ class Section(Structure):
     def __init__(self, *args, **kw):
         super().__init__(*args, **kw)
         self.type_flags = 1999801
-
-
-bone_filter_mode_items = (
-    ('ALL', 'All', 'All bones will be exported'),
-    ('BONE_COLLECTIONS', 'Bone Collections', 'Only bones belonging to the selected bone collections and their ancestors will be exported')
-)

io_scene_psk_psa/shared/dfs.py

@@ -1,9 +1,9 @@
-'''
+"""
 Depth-first object iterator functions for Blender collections and view layers.
 
 These functions are used to iterate over objects in a collection or view layer in a depth-first manner, including
 instances. This is useful for exporters that need to traverse the object hierarchy in a predictable order.
-'''
+"""
 
 from typing import Optional, Set, Iterable, List
 
@@ -12,9 +12,9 @@ from mathutils import Matrix
 
 
 class DfsObject:
-    '''
+    """
     Represents an object in a depth-first search.
-    '''
+    """
     def __init__(self, obj: Object, instance_objects: List[Object], matrix_world: Matrix):
         self.obj = obj
         self.instance_objects = instance_objects
@@ -22,34 +22,35 @@ class DfsObject:
 
     @property
     def is_visible(self) -> bool:
-        '''
+        """
         Check if the object is visible.
+
         @return: True if the object is visible, False otherwise.
-        '''
+        """
         if self.instance_objects:
             return self.instance_objects[-1].visible_get()
         return self.obj.visible_get()
 
     @property
     def is_selected(self) -> bool:
-        '''
+        """
         Check if the object is selected.
         @return: True if the object is selected, False otherwise.
-        '''
+        """
         if self.instance_objects:
             return self.instance_objects[-1].select_get()
         return self.obj.select_get()
 
 
-
 def _dfs_object_children(obj: Object, collection: Collection) -> Iterable[Object]:
-    '''
+    """
     Construct a list of objects in hierarchy order from `collection.objects`, only keeping those that are in the
     collection.
+
     @param obj: The object to start the search from.
     @param collection:  The collection to search in.
     @return: An iterable of objects in hierarchy order.
-    '''
+    """
     yield obj
     for child in obj.children:
         if child.name in collection.objects:
@@ -57,12 +58,13 @@ def _dfs_object_children(obj: Object, collection: Collection) -> Iterable[Object
 
 
 def dfs_objects_in_collection(collection: Collection) -> Iterable[Object]:
-    '''
+    """
     Returns a depth-first iterator over all objects in a collection, only keeping those that are directly in the
     collection.
+
     @param collection: The collection to search in.
     @return: An iterable of objects in hierarchy order.
-    '''
+    """
     objects_hierarchy = []
     for obj in collection.objects:
         if obj.parent is None or obj.parent not in set(collection.objects):
@@ -72,11 +74,12 @@ def dfs_objects_in_collection(collection: Collection) -> Iterable[Object]:
 
 
 def dfs_collection_objects(collection: Collection, visible_only: bool = False) -> Iterable[DfsObject]:
-    '''
+    """
     Depth-first search of objects in a collection, including recursing into instances.
+
     @param collection: The collection to search in.
     @return: An iterable of tuples containing the object, the instance objects, and the world matrix.
-    '''
+    """
     yield from _dfs_collection_objects_recursive(collection)
 
 
@@ -86,15 +89,16 @@ def _dfs_collection_objects_recursive(
         matrix_world: Matrix = Matrix.Identity(4),
         visited: Optional[Set[Object]]=None
 ) -> Iterable[DfsObject]:
-    '''
+    """
     Depth-first search of objects in a collection, including recursing into instances.
     This is a recursive function.
+
     @param collection: The collection to search in.
     @param instance_objects: The running hierarchy of instance objects.
     @param matrix_world: The world matrix of the current object.
     @param visited: A set of visited object-instance pairs.
     @return: An iterable of tuples containing the object, the instance objects, and the world matrix.
-    '''
+    """
 
     # We want to also yield the top-level instance object so that callers can inspect the selection status etc.
     if visited is None:
@@ -128,11 +132,12 @@ def _dfs_collection_objects_recursive(
 
 
 def dfs_view_layer_objects(view_layer: ViewLayer) -> Iterable[DfsObject]:
-    '''
+    """
     Depth-first iterator over all objects in a view layer, including recursing into instances.
+
     @param view_layer: The view layer to inspect.
     @return: An iterable of tuples containing the object, the instance objects, and the world matrix.
-    '''
+    """
     visited = set()
     def layer_collection_objects_recursive(layer_collection: LayerCollection):
         for child in layer_collection.children:
@@ -144,12 +149,13 @@ def dfs_view_layer_objects(view_layer: ViewLayer) -> Iterable[DfsObject]:
 
 
 def _is_dfs_object_visible(obj: Object, instance_objects: List[Object]) -> bool:
-    '''
+    """
     Check if a DFS object is visible.
+
     @param obj: The object.
     @param instance_objects: The instance objects.
     @return: True if the object is visible, False otherwise.
-    '''
+    """
     if instance_objects:
         return instance_objects[-1].visible_get()
     return obj.visible_get()

io_scene_psk_psa/shared/helpers.py

@@ -1,9 +1,11 @@
-from typing import List, Iterable, cast, Tuple
-
 import bpy
+from collections import Counter
+from typing import List, Iterable, Optional, Dict, Tuple, cast as typing_cast
 from bpy.props import CollectionProperty
-from bpy.types import AnimData, Object
-from bpy.types import Armature
+from bpy.types import Armature, AnimData, Object
+from mathutils import Matrix, Vector, Quaternion as BpyQuaternion
+from .data import Vector3, Quaternion
+from ..shared.data import PsxBone
 
 
 def rgb_to_srgb(c: float):
@@ -26,7 +28,7 @@ def get_nla_strips_in_frame_range(animation_data: AnimData, frame_min: float, fr
                 yield strip
 
 
-def populate_bone_collection_list(armature_object: Object, bone_collection_list: CollectionProperty) -> None:
+def populate_bone_collection_list(armature_objects: Iterable[Object], bone_collection_list: CollectionProperty) -> None:
     """
     Updates the bone collections collection.
 
@@ -36,7 +38,7 @@ def populate_bone_collection_list(armature_object: Object, bone_collection_list:
     has_selected_collections = any([g.is_selected for g in bone_collection_list])
     unassigned_collection_is_selected, selected_assigned_collection_names = True, []
 
-    if armature_object is None:
+    if not armature_objects:
         return
 
     if has_selected_collections:
@@ -51,24 +53,27 @@ def populate_bone_collection_list(armature_object: Object, bone_collection_list:
 
     bone_collection_list.clear()
 
-    armature = cast(Armature, armature_object.data)
+    for armature_object in armature_objects:
+        armature = typing_cast(Armature, armature_object.data)
 
-    if armature is None:
-        return
+        if armature is None:
+            return
 
-    item = bone_collection_list.add()
-    item.name = 'Unassigned'
-    item.index = -1
-    # Count the number of bones without an assigned bone collection
-    item.count = sum(map(lambda bone: 1 if len(bone.collections) == 0 else 0, armature.bones))
-    item.is_selected = unassigned_collection_is_selected
-
-    for bone_collection_index, bone_collection in enumerate(armature.collections_all):
         item = bone_collection_list.add()
-        item.name = bone_collection.name
-        item.index = bone_collection_index
-        item.count = len(bone_collection.bones)
-        item.is_selected = bone_collection.name in selected_assigned_collection_names if has_selected_collections else True
+        item.armature_object_name = armature_object.name
+        item.name = 'Unassigned' # TODO: localize
+        item.index = -1
+        # Count the number of bones without an assigned bone collection
+        item.count = sum(map(lambda bone: 1 if len(bone.collections) == 0 else 0, armature.bones))
+        item.is_selected = unassigned_collection_is_selected
+
+        for bone_collection_index, bone_collection in enumerate(armature.collections_all):
+            item = bone_collection_list.add()
+            item.armature_object_name = armature_object.name
+            item.name = bone_collection.name
+            item.index = bone_collection_index
+            item.count = len(bone_collection.bones)
+            item.is_selected = bone_collection.name in selected_assigned_collection_names if has_selected_collections else True
 
 
 def get_export_bone_names(armature_object: Object, bone_filter_mode: str, bone_collection_indices: Iterable[int]) -> List[str]:
@@ -77,15 +82,15 @@ def get_export_bone_names(armature_object: Object, bone_filter_mode: str, bone_c
 
     Note that the ancestors of bones within the bone collections will also be present in the returned list.
 
-    :param armature_object: Blender object with type 'ARMATURE'
-    :param bone_filter_mode: One of ['ALL', 'BONE_COLLECTIONS']
+    :param armature_object: Blender object with type `'ARMATURE'`
+    :param bone_filter_mode: One of `['ALL', 'BONE_COLLECTIONS']`
     :param bone_collection_indices: A list of bone collection indices to export.
     :return: A sorted list of bone indices that should be exported.
     """
     if armature_object is None or armature_object.type != 'ARMATURE':
         raise ValueError('An armature object must be supplied')
 
-    armature_data = cast(Armature, armature_object.data)
+    armature_data = typing_cast(Armature, armature_object.data)
     bones = armature_data.bones
     bone_names = [x.name for x in bones]
 
@@ -128,6 +133,7 @@ def get_export_bone_names(armature_object: Object, bone_filter_mode: str, bone_c
     bone_names = [bones[x[0]].name for x in bone_indices]
 
     # Ensure that the hierarchy we are sending back has a single root bone.
+    # TODO: This is only relevant if we are exporting a single armature; how should we reorganize this call?
     bone_indices = [x[0] for x in bone_indices]
     root_bones = [bones[bone_index] for bone_index in bone_indices if bones[bone_index].parent is None]
     if len(root_bones) > 1:
@@ -156,55 +162,270 @@ def is_bdk_addon_loaded() -> bool:
     return 'bdk' in dir(bpy.ops)
 
 
-class SemanticVersion(object):
-    def __init__(self, version: Tuple[int, int, int]):
-        self.major, self.minor, self.patch = version
+def convert_string_to_cp1252_bytes(string: str) -> bytes:
+    try:
+        return bytes(string, encoding='windows-1252')
+    except UnicodeEncodeError as e:
+        raise RuntimeError(f'The string "{string}" contains characters that cannot be encoded in the Windows-1252 codepage') from e
 
-    def __iter__(self):
-        yield self.major
-        yield self.minor
-        yield self.patch
 
-    @staticmethod
-    def compare(lhs: 'SemanticVersion', rhs: 'SemanticVersion') -> int:
-        """
-        Compares two semantic versions.
+# TODO: Perhaps export space should just be a transform matrix, since the below is not actually used unless we're using WORLD space.
+def create_psx_bones_from_blender_bones(
+        bones: List[bpy.types.Bone],
+        export_space: str = 'WORLD',
+        armature_object_matrix_world: Matrix = Matrix.Identity(4),
+        scale = 1.0,
+        forward_axis: str = 'X',
+        up_axis: str = 'Z',
+        root_bone: Optional = None,
+) -> List[PsxBone]:
 
-        Returns:
-            -1 if lhs < rhs
-             0 if lhs == rhs
-             1 if lhs > rhs
-        """
-        for l, r in zip(lhs, rhs):
-            if l < r:
-                return -1
-            if l > r:
-                return 1
-        return 0
+    scale_matrix = Matrix.Scale(scale, 4)
 
-    def __str__(self):
-        return f'{self.major}.{self.minor}.{self.patch}'
+    coordinate_system_transform = get_coordinate_system_transform(forward_axis, up_axis)
+    coordinate_system_default_rotation = coordinate_system_transform.to_quaternion()
 
-    def __repr__(self):
-        return str(self)
+    psx_bones = []
+    for bone in bones:
+        psx_bone = PsxBone()
+        psx_bone.name = convert_string_to_cp1252_bytes(bone.name)
 
-    def __eq__(self, other):
-        return self.compare(self, other) == 0
+        try:
+            parent_index = bones.index(bone.parent)
+            psx_bone.parent_index = parent_index
+            psx_bones[parent_index].children_count += 1
+        except ValueError:
+            psx_bone.parent_index = 0
 
-    def __ne__(self, other):
-        return not self == other
+        if bone.parent is not None:
+            rotation = bone.matrix.to_quaternion().conjugated()
+            inverse_parent_rotation = bone.parent.matrix.to_quaternion().inverted()
+            parent_head = inverse_parent_rotation @ bone.parent.head
+            parent_tail = inverse_parent_rotation @ bone.parent.tail
+            location = (parent_tail - parent_head) + bone.head
+        elif bone.parent is None and root_bone is not None:
+            # This is a special case for the root bone when export
+            # Because the root bone and child bones are in different spaces, we need to treat the root bone of this
+            # armature as though it were a child bone.
+            bone_rotation = bone.matrix.to_quaternion().conjugated()
+            local_rotation = armature_object_matrix_world.to_3x3().to_quaternion().conjugated()
+            rotation = bone_rotation @ local_rotation
+            translation, _, scale = armature_object_matrix_world.decompose()
+            # Invert the scale of the armature object matrix.
+            inverse_scale_matrix = Matrix.Identity(4)
+            inverse_scale_matrix[0][0] = 1.0 / scale.x
+            inverse_scale_matrix[1][1] = 1.0 / scale.y
+            inverse_scale_matrix[2][2] = 1.0 / scale.z
 
-    def __lt__(self, other):
-        return self.compare(self, other) == -1
+            translation = translation @ inverse_scale_matrix
+            location = translation + bone.head
+        else:
+            def get_armature_local_matrix():
+                match export_space:
+                    case 'WORLD':
+                        return armature_object_matrix_world
+                    case 'ARMATURE':
+                        return Matrix.Identity(4)
+                    case 'ROOT':
+                        return bone.matrix.inverted()
+                    case _:
+                        assert False, f'Invalid export space: {export_space}'
 
-    def __le__(self, other):
-        return self.compare(self, other) <= 0
+            armature_local_matrix = get_armature_local_matrix()
+            location = armature_local_matrix @ bone.head
+            location = coordinate_system_transform @ location
+            bone_rotation = bone.matrix.to_quaternion().conjugated()
+            local_rotation = armature_local_matrix.to_3x3().to_quaternion().conjugated()
+            rotation = bone_rotation @ local_rotation
+            rotation.conjugate()
+            rotation = coordinate_system_default_rotation @ rotation
 
-    def __gt__(self, other):
-        return self.compare(self, other) == 1
+        location = scale_matrix @ location
 
-    def __ge__(self, other):
-        return self.compare(self, other) >= 0
+        # If the armature object has been scaled, we need to scale the bone's location to match.
+        _, _, armature_object_scale = armature_object_matrix_world.decompose()
+        location.x *= armature_object_scale.x
+        location.y *= armature_object_scale.y
+        location.z *= armature_object_scale.z
 
-    def __hash__(self):
-        return hash((self.major, self.minor, self.patch))
+        psx_bone.location.x = location.x
+        psx_bone.location.y = location.y
+        psx_bone.location.z = location.z
+
+        psx_bone.rotation.w = rotation.w
+        psx_bone.rotation.x = rotation.x
+        psx_bone.rotation.y = rotation.y
+        psx_bone.rotation.z = rotation.z
+
+        psx_bones.append(psx_bone)
+
+    return psx_bones
+
+
+class PsxBoneCreateResult:
+    def __init__(self,
+                 bones: List[Tuple[PsxBone, Optional[Object]]],  # List of tuples of (psx_bone, armature_object)
+                 armature_object_root_bone_indices: Dict[Object, int],
+                 armature_object_bone_names: Dict[Object, List[str]],
+                 ):
+        self.bones = bones
+        self.armature_object_root_bone_indices = armature_object_root_bone_indices
+        self.armature_object_bone_names = armature_object_bone_names
+    
+    @property
+    def has_false_root_bone(self) -> bool:
+        return len(self.bones) > 0 and self.bones[0][1] is None
+
+
+def convert_bpy_quaternion_to_psx_quaternion(other: BpyQuaternion) -> Quaternion:
+    quaternion = Quaternion()
+    quaternion.x = other.x
+    quaternion.y = other.y
+    quaternion.z = other.z
+    quaternion.w = other.w
+    return quaternion
+
+
+def create_psx_bones(
+        armature_objects: List[Object],
+        export_space: str = 'WORLD',
+        root_bone_name: str = 'ROOT',
+        forward_axis: str = 'X',
+        up_axis: str = 'Z',
+        scale: float = 1.0,
+        bone_filter_mode: str = 'ALL',
+        bone_collection_indices: Optional[List[Tuple[str, int]]] = None,
+) -> PsxBoneCreateResult:
+    """
+    Creates a list of PSX bones from the given armature objects and options.
+    This function will throw a RuntimeError if multiple armature objects are passed in and the export space is not WORLD.
+    It will also throw a RuntimeError if the bone names are not unique when compared case-insensitively.
+    """
+    if bone_collection_indices is None:
+        bone_collection_indices = []
+
+    bones: List[Tuple[PsxBone, Optional[Object]]] = []
+
+    if export_space != 'WORLD' and len(armature_objects) > 1:
+        armature_object_names = [armature_object.name for armature_object in armature_objects]
+        raise RuntimeError(f'When exporting multiple armatures, the Export Space must be World. The following armatures are attempting to be exported: {armature_object_names}')
+
+    coordinate_system_matrix = get_coordinate_system_transform(forward_axis, up_axis)
+    coordinate_system_default_rotation = coordinate_system_matrix.to_quaternion()
+
+    total_bone_count = sum(len(armature_object.data.bones) for armature_object in armature_objects)
+
+
+    # Store the bone names to be exported for each armature object.
+    armature_object_bone_names: Dict[Object, List[str]] = dict()
+    for armature_object in  armature_objects:
+        armature_bone_collection_indices = [x[1] for x in bone_collection_indices if x[0] == armature_object.name]
+        bone_names = get_export_bone_names(armature_object, bone_filter_mode, armature_bone_collection_indices)
+        armature_object_bone_names[armature_object] = bone_names
+
+    # Store the index of the root bone for each armature object.
+    # We will need this later to correctly assign vertex weights.
+    armature_object_root_bone_indices: Dict[Optional[Object], int] = dict()
+
+    if len(armature_objects) == 0 or total_bone_count == 0:
+        # If the mesh has no armature object or no bones, simply assign it a dummy bone at the root to satisfy the
+        # requirement that a PSK file must have at least one bone.
+        psx_bone = PsxBone()
+        psx_bone.name = convert_string_to_cp1252_bytes(root_bone_name)
+        psx_bone.flags = 0
+        psx_bone.children_count = 0
+        psx_bone.parent_index = 0
+        psx_bone.location = Vector3.zero()
+        psx_bone.rotation = convert_bpy_quaternion_to_psx_quaternion(coordinate_system_default_rotation)
+        bones.append((psx_bone, None))
+
+        armature_object_root_bone_indices[None] = 0
+    else:
+        # If we have multiple armature objects, create a root bone at the world origin.
+        if len(armature_objects) > 1:
+            psx_bone = PsxBone()
+            psx_bone.name = convert_string_to_cp1252_bytes(root_bone_name)
+            psx_bone.flags = 0
+            psx_bone.children_count = total_bone_count
+            psx_bone.parent_index = 0
+            psx_bone.location = Vector3.zero()
+            psx_bone.rotation = convert_bpy_quaternion_to_psx_quaternion(coordinate_system_default_rotation)
+            bones.append((psx_bone, None))
+
+            armature_object_root_bone_indices[None] = 0
+
+        root_bone = bones[0][0] if len(bones) > 0 else None
+
+        for armature_object in armature_objects:
+            bone_names = armature_object_bone_names[armature_object]
+            armature_data = typing_cast(Armature, armature_object.data)
+            armature_bones = [armature_data.bones[bone_name] for bone_name in bone_names]
+
+            armature_psx_bones = create_psx_bones_from_blender_bones(
+                bones=armature_bones,
+                export_space=export_space,
+                armature_object_matrix_world=armature_object.matrix_world,
+                scale=scale,
+                forward_axis=forward_axis,
+                up_axis=up_axis,
+                root_bone=root_bone,
+            )
+
+            # If we are appending these bones to an existing list of bones, we need to adjust the parent indices for
+            # all the non-root bones.
+            if len(bones) > 0:
+                parent_index_offset = len(bones)
+                for bone in armature_psx_bones[1:]:
+                    bone.parent_index += parent_index_offset
+
+            armature_object_root_bone_indices[armature_object] = len(bones)
+
+            bones.extend((psx_bone, armature_object) for psx_bone in armature_psx_bones)
+
+    # Check if there are bone name conflicts between armatures.
+    bone_name_counts = Counter(bone[0].name.decode('windows-1252').upper() for bone in bones)
+    for bone_name, count in bone_name_counts.items():
+        if count > 1:
+            error_message = f'Found {count} bones with the name "{bone_name}". '
+            f'Bone names must be unique when compared case-insensitively.'
+
+            if len(armature_objects) > 1 and bone_name == root_bone_name.upper():
+                error_message += f' This is the name of the automatically generated root bone. Consider changing this '
+                f''
+                raise RuntimeError(error_message)
+
+    return PsxBoneCreateResult(
+        bones=bones,
+        armature_object_root_bone_indices=armature_object_root_bone_indices,
+        armature_object_bone_names=armature_object_bone_names,
+    )
+
+
+def get_vector_from_axis_identifier(axis_identifier: str) -> Vector:
+    match axis_identifier:
+        case 'X':
+            return Vector((1.0, 0.0, 0.0))
+        case 'Y':
+            return Vector((0.0, 1.0, 0.0))
+        case 'Z':
+            return Vector((0.0, 0.0, 1.0))
+        case '-X':
+            return Vector((-1.0, 0.0, 0.0))
+        case '-Y':
+            return Vector((0.0, -1.0, 0.0))
+        case '-Z':
+            return Vector((0.0, 0.0, -1.0))
+        case _:
+            assert False, f'Invalid axis identifier: {axis_identifier}'
+
+
+def get_coordinate_system_transform(forward_axis: str = 'X', up_axis: str = 'Z') -> Matrix:
+    forward = get_vector_from_axis_identifier(forward_axis)
+    up = get_vector_from_axis_identifier(up_axis)
+    left = up.cross(forward)
+    return Matrix((
+        (forward.x, forward.y, forward.z, 0.0),
+        (left.x, left.y, left.z, 0.0),
+        (up.x, up.y, up.z, 0.0),
+        (0.0, 0.0, 0.0, 1.0)
+    ))

io_scene_psk_psa/shared/semver.py

@@ -0,0 +1,54 @@
+from typing import Tuple
+
+class SemanticVersion(object):
+    def __init__(self, version: Tuple[int, int, int]):
+        self.major, self.minor, self.patch = version
+
+    def __iter__(self):
+        yield self.major
+        yield self.minor
+        yield self.patch
+
+    @staticmethod
+    def compare(lhs: 'SemanticVersion', rhs: 'SemanticVersion') -> int:
+        """
+        Compares two semantic versions.
+
+        Returns:
+            -1 if lhs < rhs
+             0 if lhs == rhs
+             1 if lhs > rhs
+        """
+        for l, r in zip(lhs, rhs):
+            if l < r:
+                return -1
+            if l > r:
+                return 1
+        return 0
+
+    def __str__(self):
+        return f'{self.major}.{self.minor}.{self.patch}'
+
+    def __repr__(self):
+        return str(self)
+
+    def __eq__(self, other):
+        return self.compare(self, other) == 0
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __lt__(self, other):
+        return self.compare(self, other) == -1
+
+    def __le__(self, other):
+        return self.compare(self, other) <= 0
+
+    def __gt__(self, other):
+        return self.compare(self, other) == 1
+
+    def __ge__(self, other):
+        return self.compare(self, other) >= 0
+
+    def __hash__(self):
+        return hash((self.major, self.minor, self.patch))

io_scene_psk_psa/shared/types.py

@@ -1,17 +1,26 @@
-from bpy.props import StringProperty, IntProperty, BoolProperty, FloatProperty
+import bpy
+from bpy.props import CollectionProperty, EnumProperty, StringProperty, IntProperty, BoolProperty, FloatProperty
 from bpy.types import PropertyGroup, UIList, UILayout, Context, AnyType, Panel
 
 
 class PSX_UL_bone_collection_list(UIList):
 
-    def draw_item(self, context: Context, layout: UILayout, data: AnyType, item: AnyType, icon: int,
-                  active_data: AnyType, active_property: str, index: int = 0, flt_flag: int = 0):
+    def draw_item(self, _context: Context, layout: UILayout, _data: AnyType, item: AnyType, _icon: int,
+                  _active_data: AnyType, _active_property: str, _index: int = 0, _flt_flag: int = 0):
         row = layout.row()
+
         row.prop(item, 'is_selected', text=getattr(item, 'name'))
         row.label(text=str(getattr(item, 'count')), icon='BONE_DATA')
 
+        armature_object = bpy.data.objects.get(item.armature_object_name, None)
+        if armature_object is None:
+            row.label(icon='ERROR')
+        else:
+            row.label(text=armature_object.name, icon='ARMATURE_DATA')
+
 
 class PSX_PG_bone_collection_list_item(PropertyGroup):
+    armature_object_name: StringProperty()
     name: StringProperty()
     index: IntProperty()
     count: IntProperty()
@@ -47,6 +56,89 @@ class PSX_PT_action(Panel):
         flow.prop(action.psa_export, 'fps')
 
 
+bone_filter_mode_items = (
+    ('ALL', 'All', 'All bones will be exported'),
+    ('BONE_COLLECTIONS', 'Bone Collections', 'Only bones belonging to the selected bone collections and their ancestors will be exported')
+)
+
+axis_identifiers = ('X', 'Y', 'Z', '-X', '-Y', '-Z')
+forward_items = (
+    ('X', 'X Forward', ''),
+    ('Y', 'Y Forward', ''),
+    ('Z', 'Z Forward', ''),
+    ('-X', '-X Forward', ''),
+    ('-Y', '-Y Forward', ''),
+    ('-Z', '-Z Forward', ''),
+)
+
+up_items = (
+    ('X', 'X Up', ''),
+    ('Y', 'Y Up', ''),
+    ('Z', 'Z Up', ''),
+    ('-X', '-X Up', ''),
+    ('-Y', '-Y Up', ''),
+    ('-Z', '-Z Up', ''),
+)
+
+
+def forward_axis_update(self, __context):
+    if self.forward_axis == self.up_axis:
+        # Automatically set the up axis to the next available axis
+        self.up_axis = next((axis for axis in axis_identifiers if axis != self.forward_axis), 'Z')
+
+
+def up_axis_update(self, __context):
+    if self.up_axis == self.forward_axis:
+        # Automatically set the forward axis to the next available axis
+        self.forward_axis = next((axis for axis in axis_identifiers if axis != self.up_axis), 'X')
+
+
+class ForwardUpAxisMixin:
+    forward_axis: EnumProperty(
+        name='Forward',
+        items=forward_items,
+        default='X',
+        update=forward_axis_update
+    )
+    up_axis: EnumProperty(
+        name='Up',
+        items=up_items,
+        default='Z',
+        update=up_axis_update
+    )
+
+
+export_space_items = [
+    ('WORLD', 'World', 'Export in world space'),
+    ('ARMATURE', 'Armature', 'Export the local space of the armature object'),
+    ('ROOT', 'Root', 'Export in the space of the root bone')
+]
+
+
+class ExportSpaceMixin:
+    export_space: EnumProperty(
+        name='Export Space',
+        items=export_space_items,
+        default='WORLD'
+    )
+ 
+ 
+class PsxBoneExportMixin:
+    bone_filter_mode: EnumProperty(
+        name='Bone Filter',
+        options=set(),
+        description='',
+        items=bone_filter_mode_items,
+    )
+    bone_collection_list: CollectionProperty(type=PSX_PG_bone_collection_list_item)
+    bone_collection_list_index: IntProperty(default=0, name='', description='')
+    root_bone_name: StringProperty(
+        name='Root Bone Name',
+        description='The name of the root bone when exporting a PSK with either no armature or multiple armatures',
+        default='ROOT',
+    )
+
+
 classes = (
     PSX_PG_action_export,
     PSX_PG_bone_collection_list_item,

io_scene_psk_psa/shared/ui.py

@@ -1,6 +1,6 @@
 from bpy.types import UILayout
 
-from .data import bone_filter_mode_items
+from .types import bone_filter_mode_items
 
 
 def is_bone_filter_mode_item_available(pg, identifier):

pyproject.toml

@@ -0,0 +1,12 @@
+[project]
+name = "io_scene_psk_psa"
+
+[pytest]
+blender-addons-dirs = "io_scene_psk_psa"
+testpaths = "../tests"
+
+[tool.coverage.run]
+branch = true
+
+[tool.coverage.report]
+ignore_errors = true

test.sh

@@ -0,0 +1,2 @@
+# usr/bin/env bash
+docker run -it --volume ${PWD}:/io_scene_psk_psa --volume ${PWD}/io_scene_psk_psa:/addons/io_scene_psk_psa --volume ${PWD}/tests:/tests  $(docker build -q .)

tests/psa_import_test.py

@@ -0,0 +1,39 @@
+import bpy
+import pytest
+
+SHREK_PSK_FILEPATH = 'tests/data/Shrek.psk'
+SHREK_PSA_FILEPATH = 'tests/data/Shrek.psa'
+
+
+@pytest.fixture(autouse=True)
+def run_before_and_after_Tests(tmpdir):
+    # Setup: Run before the tests
+    bpy.ops.wm.read_homefile(app_template='')
+    yield
+    # Teardown: Run after the tests
+    pass
+
+
+def test_psa_import_all():
+    assert bpy.ops.psk.import_file(
+        filepath=SHREK_PSK_FILEPATH,
+        components='ALL',
+        ) == {'FINISHED'}, "PSK import failed."
+
+    armature_object = bpy.data.objects.get('Shrek', None)
+    assert armature_object is not None, "Armature object not found in the scene."
+    assert armature_object.type == 'ARMATURE', "Object is not of type ARMATURE."
+
+    # Select the armature object
+    bpy.context.view_layer.objects.active = armature_object
+    armature_object.select_set(True)
+
+    # Import the associated PSA file with import_all operator.
+    assert bpy.ops.psa.import_all(
+        filepath=SHREK_PSA_FILEPATH
+        ) == {'FINISHED'}, "PSA import failed."
+    
+    # TODO: More thorough tests on the imported data for the animations.
+    EXPECTED_ACTION_COUNT = 135
+    assert len(bpy.data.actions) == EXPECTED_ACTION_COUNT, \
+        f"Expected {EXPECTED_ACTION_COUNT} actions, but found {len(bpy.data.actions)}."

tests/psk_import_test.py

@@ -0,0 +1,282 @@
+import bpy
+import pytest
+
+SUZANNE_FILEPATH = 'tests/data/Suzanne.psk'
+SARGE_FILEPATH = 'tests/data/CS_Sarge_S0_Skelmesh.pskx'
+SLURP_MONSTER_AXE_FILEPATH = 'tests/data/Slurp_Monster_Axe_LOD0.psk'
+
+
+@pytest.fixture(autouse=True)
+def run_before_and_after_Tests(tmpdir):
+    # Setup: Run before the tests
+    bpy.ops.wm.read_homefile(app_template='')
+    yield
+    # Teardown: Run after the tests
+    pass
+
+
+def test_psk_import_all():
+    assert bpy.ops.psk.import_file(
+        filepath=SUZANNE_FILEPATH,
+        components='ALL',
+        ) == {'FINISHED'}
+
+    armature_object = bpy.data.objects.get('Suzanne', None)
+
+    assert armature_object is not None, "Armature object not found in the scene"
+    assert armature_object.type == 'ARMATURE', "Armature object type should be ARMATURE"
+    assert armature_object is not None, "Armature object not found in the scene"
+    assert len(armature_object.children) == 1, "Armature object should have one child"
+
+    armature_data = armature_object.data
+
+    assert len(armature_data.bones) == 1, "Armature should have one bone"
+
+    mesh_object = bpy.data.objects.get('Suzanne.001', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+
+    mesh_data = mesh_object.data
+
+    assert len(mesh_data.vertices) == 507
+    assert len(mesh_data.polygons) == 968
+
+
+def test_psk_import_armature_only():
+    assert bpy.ops.psk.import_file(
+        filepath=SUZANNE_FILEPATH,
+        components='ARMATURE',
+        ) == {'FINISHED'}
+
+    armature_object = bpy.data.objects.get('Suzanne', None)
+
+    assert armature_object.type == 'ARMATURE', "Armature object type should be ARMATURE"
+    assert armature_object is not None, "Armature object not found in the scene"
+    assert len(armature_object.children) == 0, "Armature object should have no children"
+
+    armature_data = armature_object.data
+
+    assert len(armature_data.bones) == 1, "Armature should have one bone"
+
+
+def test_psk_import_mesh_only():
+    assert bpy.ops.psk.import_file(
+        filepath=SUZANNE_FILEPATH,
+        components='MESH',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('Suzanne', None)
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+    assert mesh_object is not None, "Mesh object not found in the scene"
+
+    mesh_data = mesh_object.data
+
+    assert len(mesh_data.vertices) == 507
+    assert len(mesh_data.polygons) == 968
+
+
+def test_psk_import_scale():
+    """
+    Test the import of a PSK file with a scale factor of 2.0.
+    The scale factor is applied to the armature object.
+    """
+    assert bpy.ops.psk.import_file(
+        filepath=SUZANNE_FILEPATH,
+        components='ALL',
+        scale=2.0,
+        ) == {'FINISHED'}
+
+    armature_object = bpy.data.objects.get('Suzanne', None)
+    assert armature_object is not None, "Armature object not found in the scene"
+    assert armature_object.type == 'ARMATURE', "Armature object type should be ARMATURE"
+    assert tuple(armature_object.scale) == (2.0, 2.0, 2.0), "Armature object scale should be (2.0, 2.0, 2.0)"
+
+
+def test_psk_import_bone_length():
+    bone_length = 1.25
+
+    assert bpy.ops.psk.import_file(
+        filepath=SUZANNE_FILEPATH,
+        components='ARMATURE',
+        bone_length=bone_length,
+        ) == {'FINISHED'}
+    
+    armature_object = bpy.data.objects.get('Suzanne', None)
+    assert armature_object is not None, "Armature object not found in the scene"
+    assert armature_object.type == 'ARMATURE', "Armature object type should be ARMATURE"
+
+    armature_data = armature_object.data
+    assert armature_data is not None, "Armature data not found in the scene"
+    assert len(armature_data.bones) == 1, "Armature should have one bone"
+    assert 'ROOT' in armature_data.bones, "Armature should have a bone named 'ROOT'"
+
+    root_bone = armature_data.bones['ROOT']
+    assert tuple(root_bone.head) == (0.0, 0.0, 0.0), "Bone head should be (0.0, 0.0, 0.0)"
+    assert tuple(root_bone.tail) == (0.0, bone_length, 0.0), f"Bone tail should be (0.0, {bone_length}, 0.0)"
+
+
+def test_psk_import_with_vertex_normals():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_normals=True,
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert mesh_data.has_custom_normals, "Mesh should have custom normals"
+
+
+def test_psk_import_without_vertex_normals():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_normals=False,
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert not mesh_data.has_custom_normals, "Mesh should not have custom normals"
+
+
+def test_psk_import_with_vertex_colors_srgba():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_colors=True,
+        vertex_color_space='SRGBA',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert len(mesh_data.color_attributes) == 1, "Mesh should have one vertex color layer"
+    assert mesh_data.color_attributes[0].name == 'VERTEXCOLOR', "Vertex color layer should be named 'VERTEXCOLOR'"
+    assert tuple(mesh_data.color_attributes[0].data[3303].color) == (0.34586891531944275, 0.0, 0.0, 1.0), "Unexpected vertex color value"
+
+
+def test_psk_import_vertex_colors_linear():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_colors=True,
+        vertex_color_space='LINEAR',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert len(mesh_data.color_attributes) == 1, "Mesh should have one vertex color layer"
+    assert mesh_data.color_attributes[0].name == 'VERTEXCOLOR', "Vertex color layer should be named 'VERTEXCOLOR'"
+    assert tuple(mesh_data.color_attributes[0].data[3303].color) == (0.09803921729326248, 0.0, 0.0, 1.0), "Unexpected vertex color value"
+
+
+def test_psk_import_without_vertex_colors():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_colors=False,
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert len(mesh_data.color_attributes) == 0, "Mesh should not have any vertex color layers"
+
+
+def test_psk_import_extra_uvs():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        should_import_vertex_colors=True,
+        vertex_color_space='LINEAR',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert len(mesh_data.uv_layers) == 2, "Mesh should have two UV layers"
+
+    assert mesh_data.uv_layers[0].name == 'UVMap', "First UV layer should be named 'UVMap'"
+    assert mesh_data.uv_layers[1].name == 'EXTRAUV0', "Second UV layer should be named 'EXTRAUV0'"
+
+
+def test_psk_import_materials():
+    assert bpy.ops.psk.import_file(
+        filepath=SARGE_FILEPATH,
+        components='MESH',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('CS_Sarge_S0_Skelmesh', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+
+    mesh_data = mesh_object.data
+
+    assert mesh_data is not None, "Mesh data not found in the scene"
+    assert len(mesh_data.materials) == 4, "Mesh should have four materials"
+    material_names = (
+        'CS_Sarge_S0_MI',
+        'TP_Core_Eye_MI',
+        'AB_Sarge_S0_E_StimPack_MI1',
+        'CS_Sarge_S0_MI'
+    )
+    for i, material in enumerate(mesh_data.materials):
+        assert material.name == material_names[i], f"Material {i} name should be {material_names[i]}"
+
+
+def test_psk_import_shape_keys():
+    assert bpy.ops.psk.import_file(
+        filepath=SLURP_MONSTER_AXE_FILEPATH,
+        components='MESH',
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('Slurp_Monster_Axe_LOD0', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+    assert mesh_object.data.shape_keys is not None, "Mesh object should have shape keys"
+
+    shape_key_names = (
+        'MORPH_BASE',
+        'pickaxe',
+        'axe',
+        'Blob_03',
+        'Blob02',
+        'Blob01',
+    )
+    shape_keys = mesh_object.data.shape_keys.key_blocks
+    assert len(shape_keys) == 6, "Mesh object should have 6 shape keys"
+    for i, shape_key in enumerate(shape_keys):
+        assert shape_key.name == shape_key_names[i], f"Shape key {i} name should be {shape_key_names[i]}"
+
+def test_psk_import_without_shape_keys():
+    assert bpy.ops.psk.import_file(
+        filepath=SLURP_MONSTER_AXE_FILEPATH,
+        components='MESH',
+        should_import_shape_keys=False,
+        ) == {'FINISHED'}
+
+    mesh_object = bpy.data.objects.get('Slurp_Monster_Axe_LOD0', None)
+    assert mesh_object is not None, "Mesh object not found in the scene"
+    assert mesh_object.type == 'MESH', "Mesh object type should be MESH"
+    assert mesh_object.data.shape_keys is None, "Mesh object should not have shape keys"
+    

tests/requirements.txt

@@ -0,0 +1 @@
+pytest

tests/test.sh

@@ -0,0 +1,8 @@
+# usr/bin/env bash
+# This file is meant to be executed from inside a Docker container.
+# To run tests on the host system, use the `test.sh` script in the root directory.
+export BLENDER_EXECUTABLE=$(cat /blender_executable_path)
+pytest --cov-report xml --cov=/root/.config/blender -svv tests --blender-executable $BLENDER_EXECUTABLE --blender-addons-dirs ../addons
+# Fixes the paths in the coverage report to be relative to the current directory.
+sed -i 's|/root/.config/blender||g' coverage.xml
+sed -i 's|4.4/scripts/addons/io_scene_psk_psa/||g' coverage.xml