Updated the README to better reflect the capabilities of the addon

* Fixed a typo in the PSA reader
* Added the ability to define the bone length of imported PSK armatures
* The PSK import options (extra UVs, vertex colors etc.) are now actually respected if turned off
* Ran automated formatting on all the code to quell the PEP8 gods
* Incremented version to 3.0.0

.github/FUNDING.yml

@@ -0,0 +1 @@
+ko_fi: cmbasnett

README.md

@@ -1,4 +1,13 @@
-This Blender add-on allows you to export meshes and animations to the [PSK and PSA file formats](https://wiki.beyondunreal.com/PSK_%26_PSA_file_formats).
+This Blender add-on allows you to import and export meshes and animations to and from the [PSK and PSA file formats](https://wiki.beyondunreal.com/PSK_%26_PSA_file_formats).
+
+# Features
+* Full PSK/PSA import and export capabilities
+* Non-standard PSKX file format with vertex normals, extra UV channels and vertex colors is supported for import only
+* Fine-grained PSA sequence importing for efficient workflow when working with large PSA files
+* Automatic keyframe reduction on PSA import
+* PSA sequence metadata (e.g., frame rate, sequence name) is preserved on import, allowing this data to be reused on export
+* An armature's [bone groups](https://docs.blender.org/manual/en/latest/animation/armatures/properties/bone_groups.html) 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), allowing use of the [NLA](https://docs.blender.org/manual/en/latest/editors/nla/index.html) when creating sequences 
 
 # Installation
 1. Download the zip file for the latest version from the [releases](https://github.com/DarklightGames/io_export_psk_psa/releases) page.
@@ -7,7 +16,7 @@ This Blender add-on allows you to export meshes and animations to the [PSK and P
 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 Exporter" addon.
+7. Enable the newly added "Import-Export: PSK/PSA Importer/Exporter" addon.
 
 # Usage
 ## Exporting a PSK
@@ -15,11 +24,26 @@ This Blender add-on allows you to export meshes and animations to the [PSK and P
 3. Navigate to File > Export > Unreal PSK (.psk)
 4. Enter the file name and click "Export".
 
+## Importing a PSK/PSKX
+1. Navigate to File > Import > Unreal PSK (.psk/.pskx)
+2. Select the PSK file you want to import and click "Import"
+
 ## Exporting a PSA
 1. Select the armature objects you wish to export.
 2. Navigate to File > Export > Unreal PSA (.psa)
 3. Enter the file name and click "Export".
 
+## Importing a PSA
+1. Select the armature object that you wish you import actions to.
+2. Navigate to the Object Data Properties tab of the Properties editor.
+3. Navigate to the PSA Import panel.
+4. Click "Select PSA File".
+5. Select the PSA file that you want to import animations from and click "Select".
+6. In the Actions box, select which animations you want to import.
+7. Click "Import".
+
 # FAQ
-## Can I use this addon to import PSK and PSA files?
-Currently, no. If you are looking for a PSK/PSA importer, use [this one](https://github.com/Befzz/blender3d_import_psk_psa)!
+## 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.

io_export_psk_psa/__init__.py

@@ -1,73 +0,0 @@
-bl_info = {
-    "name": "PSK/PSA Exporter",
-    "author": "Colin Basnett",
-    "version": ( 1, 1, 0 ),
-    "blender": ( 2, 80, 0 ),
-    "location": "File > Export > PSK Export (.psk)",
-    "description": "PSK/PSA Export (.psk)",
-    "warning": "",
-    "wiki_url": "https://github.com/DarklightGames/io_export_psk_psa",
-    "tracker_url": "https://github.com/DarklightGames/io_export_psk_psa/issues",
-    "category": "Import-Export"
-}
-
-if 'bpy' in locals():
-    import importlib
-    importlib.reload(psk_data)
-    importlib.reload(psk_builder)
-    importlib.reload(psk_exporter)
-    importlib.reload(psk_operator)
-    importlib.reload(psa_data)
-    importlib.reload(psa_builder)
-    importlib.reload(psa_exporter)
-    importlib.reload(psa_operator)
-else:
-    # if i remove this line, it can be enabled just fine
-    from .psk import data as psk_data
-    from .psk import builder as psk_builder
-    from .psk import exporter as psk_exporter
-    from .psk import operator as psk_operator
-    from .psa import data as psa_data
-    from .psa import builder as psa_builder
-    from .psa import exporter as psa_exporter
-    from .psa import operator as psa_operator
-
-import bpy
-from bpy.props import IntProperty, CollectionProperty
-
-classes = [
-    psk_operator.PskExportOperator,
-    psa_operator.PsaExportOperator,
-    psa_operator.PSA_UL_ActionList,
-    psa_operator.ActionListItem
-]
-
-
-def psk_menu_func(self, context):
-    self.layout.operator(psk_operator.PskExportOperator.bl_idname, text ='Unreal PSK (.psk)')
-
-
-def psa_menu_func(self, context):
-    self.layout.operator(psa_operator.PsaExportOperator.bl_idname, text='Unreal PSA (.psa)')
-
-
-def register():
-    for cls in classes:
-        bpy.utils.register_class(cls)
-    bpy.types.TOPBAR_MT_file_export.append(psk_menu_func)
-    bpy.types.TOPBAR_MT_file_export.append(psa_menu_func)
-    bpy.types.Scene.psa_action_list = CollectionProperty(type=psa_operator.ActionListItem)
-    bpy.types.Scene.psa_action_list_index = IntProperty(name='index for list??', default=0)
-
-
-def unregister():
-    del bpy.types.Scene.psa_action_list_index
-    del bpy.types.Scene.psa_action_list
-    bpy.types.TOPBAR_MT_file_export.remove(psa_menu_func)
-    bpy.types.TOPBAR_MT_file_export.remove(psk_menu_func)
-    for cls in reversed(classes):
-        bpy.utils.unregister_class(cls)
-
-
-if __name__ == '__main__':
-    register()

io_export_psk_psa/data.py

@@ -1,31 +0,0 @@
-from ctypes import *
-
-
-class Vector3(Structure):
-    _fields_ = [
-        ('x', c_float),
-        ('y', c_float),
-        ('z', c_float),
-    ]
-
-
-class Quaternion(Structure):
-    _fields_ = [
-        ('x', c_float),
-        ('y', c_float),
-        ('z', c_float),
-        ('w', c_float),
-    ]
-
-
-class Section(Structure):
-    _fields_ = [
-        ('name', c_char * 20),
-        ('type_flags', c_int32),
-        ('data_size', c_int32),
-        ('data_count', c_int32)
-    ]
-
-    def __init__(self, *args, **kw):
-        super().__init__(*args, **kw)
-        self.type_flags = 1999801

io_export_psk_psa/psa/builder.py

@@ -1,130 +0,0 @@
-from .data import *
-
-
-class PsaBuilderOptions(object):
-    def __init__(self):
-        self.actions = []
-
-
-# https://git.cth451.me/cth451/blender-addons/blob/master/io_export_unreal_psk_psa.py
-class PsaBuilder(object):
-    def __init__(self):
-        # TODO: add options in here (selected anims, eg.)
-        pass
-
-    def build(self, context, options) -> Psa:
-        object = context.view_layer.objects.active
-
-        if object.type != 'ARMATURE':
-            raise RuntimeError('Selected object must be an Armature')
-
-        armature = object
-
-        if armature.animation_data is None:
-            raise RuntimeError('No animation data for armature')
-
-        psa = Psa()
-
-        bones = list(armature.data.bones)
-
-        # The order of the armature bones and the pose bones is not guaranteed to be the same.
-        # As 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]
-        pose_bones = [(bone_names.index(bone.name), bone) for bone in armature.pose.bones]
-        pose_bones.sort(key=lambda x: x[0])
-        pose_bones = [x[1] for x in pose_bones]
-
-        for bone in bones:
-            psa_bone = Psa.Bone()
-            psa_bone.name = bytes(bone.name, encoding='utf-8')
-            psa_bone.children_count = len(bone.children)
-
-            try:
-                psa_bone.parent_index = bones.index(bone.parent)
-            except ValueError:
-                psa_bone.parent_index = -1
-
-            if bone.parent is not None:
-                rotation = bone.matrix.to_quaternion()
-                rotation.x = -rotation.x
-                rotation.y = -rotation.y
-                rotation.z = -rotation.z
-                quat_parent = bone.parent.matrix.to_quaternion().inverted()
-                parent_head = quat_parent @ bone.parent.head
-                parent_tail = quat_parent @ bone.parent.tail
-                location = (parent_tail - parent_head) + bone.head
-            else:
-                location = armature.matrix_local @ bone.head
-                rot_matrix = bone.matrix @ armature.matrix_local.to_3x3()
-                rotation = rot_matrix.to_quaternion()
-
-            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)
-
-        frame_start_index = 0
-
-        for action in options.actions:
-            if len(action.fcurves) == 0:
-                continue
-
-            armature.animation_data.action = action
-            context.view_layer.update()
-
-            frame_min, frame_max = [int(x) for x in action.frame_range]
-
-            sequence = Psa.Sequence()
-            sequence.name = bytes(action.name, encoding='utf-8')
-            sequence.frame_count = frame_max - frame_min + 1
-            sequence.frame_start_index = frame_start_index
-            sequence.fps = 30  # TODO: fill in later with r
-
-            frame_count = frame_max - frame_min + 1
-
-            for frame in range(frame_count):
-                context.scene.frame_set(frame)
-
-                for bone in pose_bones:
-                    # TODO: is the cast-to-matrix necessary? (guessing no)
-                    key = Psa.Key()
-                    pose_bone_matrix = bone.matrix
-
-                    if bone.parent is not None:
-                        pose_bone_parent_matrix = bone.parent.matrix
-                        pose_bone_matrix = pose_bone_parent_matrix.inverted() @ pose_bone_matrix
-
-                    location = pose_bone_matrix.to_translation()
-                    rotation = pose_bone_matrix.to_quaternion().normalized()
-
-                    if bone.parent is not None:
-                        rotation.x = -rotation.x
-                        rotation.y = -rotation.y
-                        rotation.z = -rotation.z
-
-                    key.location.x = location.x
-                    key.location.y = location.y
-                    key.location.z = location.z
-                    key.rotation.x = rotation.x
-                    key.rotation.y = rotation.y
-                    key.rotation.z = rotation.z
-                    key.rotation.w = rotation.w
-                    key.time = 1.0 / sequence.fps
-
-                    psa.keys.append(key)
-
-                frame_start_index += 1
-
-                sequence.bone_count = len(pose_bones)
-                sequence.track_time = frame_count
-
-            psa.sequences.append(sequence)
-
-        return psa

io_export_psk_psa/psa/exporter.py

@@ -1,27 +0,0 @@
-from typing import Type
-from .data import *
-
-
-class PsaExporter(object):
-    def __init__(self, psa: Psa):
-        self.psa: Psa = psa
-
-    # This method is shared by both PSA/K file formats, move this?
-    @staticmethod
-    def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
-        section = Section()
-        section.name = name
-        if data_type is not None and data is not None:
-            section.data_size = sizeof(data_type)
-            section.data_count = len(data)
-        fp.write(section)
-        if data is not None:
-            for datum in data:
-                fp.write(datum)
-
-    def export(self, path: str):
-        with open(path, 'wb') as fp:
-            self.write_section(fp, b'ANIMHEAD')
-            self.write_section(fp, b'BONENAMES', Psa.Bone, self.psa.bones)
-            self.write_section(fp, b'ANIMINFO', Psa.Sequence, self.psa.sequences)
-            self.write_section(fp, b'ANIMKEYS', Psa.Key, self.psa.keys)

io_export_psk_psa/psa/operator.py

@@ -1,105 +0,0 @@
-from bpy.types import Operator, Action, UIList, PropertyGroup
-from bpy_extras.io_utils import ExportHelper
-from bpy.props import StringProperty, BoolProperty, CollectionProperty, PointerProperty
-from .builder import PsaBuilder, PsaBuilderOptions
-from .exporter import PsaExporter
-import bpy
-import re
-
-
-class ActionListItem(PropertyGroup):
-    action: PointerProperty(type=Action)
-    is_selected: BoolProperty(default=False)
-
-    @property
-    def name(self):
-        return self.action.name
-
-
-class PSA_UL_ActionList(UIList):
-    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
-        layout.alignment = 'LEFT'
-        layout.prop(item, 'is_selected', icon_only=True)
-        layout.label(text=item.action.name)
-
-    def filter_items(self, context, data, property):
-        # TODO: returns two lists, apparently
-        actions = getattr(data, property)
-        flt_flags = []
-        flt_neworder = []
-        if self.filter_name:
-            flt_flags = bpy.types.UI_UL_list.filter_items_by_name(self.filter_name, self.bitflag_filter_item, actions, 'name', reverse=self.use_filter_invert)
-        return flt_flags, flt_neworder
-
-
-class PsaExportOperator(Operator, ExportHelper):
-    bl_idname = 'export.psa'
-    bl_label = 'Export'
-    __doc__ = 'PSA Exporter (.psa)'
-    filename_ext = '.psa'
-    filter_glob : StringProperty(default='*.psa', options={'HIDDEN'})
-    filepath : StringProperty(
-        name='File Path',
-        description='File path used for exporting the PSA file',
-        maxlen=1024,
-        default='')
-
-    def __init__(self):
-        self.armature = None
-
-    def draw(self, context):
-        layout = self.layout
-        scene = context.scene
-        box = layout.box()
-        box.label(text='Actions', icon='ACTION')
-        row = box.row()
-        row.template_list('PSA_UL_ActionList', 'asd', scene, 'psa_action_list', scene, 'psa_action_list_index', rows=len(context.scene.psa_action_list))
-
-    def is_action_for_armature(self, action):
-        if len(action.fcurves) == 0:
-            return False
-        bone_names = set([x.name for x in self.armature.data.bones])
-        for fcurve in action.fcurves:
-            match = re.match(r'pose\.bones\["(.+)"\].\w+', fcurve.data_path)
-            if not match:
-                continue
-            bone_name = match.group(1)
-            if bone_name in bone_names:
-                return True
-        return False
-
-    def invoke(self, context, event):
-        if context.view_layer.objects.active.type != 'ARMATURE':
-            self.report({'ERROR_INVALID_CONTEXT'}, 'The selected object must be an armature.')
-            return {'CANCELLED'}
-
-        self.armature = context.view_layer.objects.active
-
-        context.scene.psa_action_list.clear()
-        for action in bpy.data.actions:
-            item = context.scene.psa_action_list.add()
-            item.action = action
-            if self.is_action_for_armature(action):
-                item.is_selected = True
-
-        if len(context.scene.psa_action_list) == 0:
-            self.report({'ERROR_INVALID_CONTEXT'}, 'There are no actions to export.')
-            return {'CANCELLED'}
-
-        context.window_manager.fileselect_add(self)
-        return {'RUNNING_MODAL'}
-
-    def execute(self, context):
-        actions = [x.action for x in context.scene.psa_action_list if x.is_selected]
-
-        if len(actions) == 0:
-            self.report({'ERROR_INVALID_CONTEXT'}, 'No actions were selected for export.')
-            return {'CANCELLED'}
-
-        options = PsaBuilderOptions()
-        options.actions = actions
-        builder = PsaBuilder()
-        psk = builder.build(context, options)
-        exporter = PsaExporter(psk)
-        exporter.export(self.filepath)
-        return {'FINISHED'}

io_export_psk_psa/psk/exporter.py

@@ -1,36 +0,0 @@
-from typing import Type
-from .data import *
-
-
-class PskExporter(object):
-    def __init__(self, psk: Psk):
-        self.psk: Psk = psk
-
-    @staticmethod
-    def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
-        section = Section()
-        section.name = name
-        if data_type is not None and data is not None:
-            section.data_size = sizeof(data_type)
-            section.data_count = len(data)
-        fp.write(section)
-        if data is not None:
-            for datum in data:
-                fp.write(datum)
-
-    def export(self, path: str):
-        with open(path, 'wb') as fp:
-            self.write_section(fp, b'ACTRHEAD')
-            self.write_section(fp, b'PNTS0000', Vector3, self.psk.points)
-
-            # WEDGES
-            if len(self.psk.wedges) <= 65536:
-                wedge_type = Psk.Wedge16
-            else:
-                wedge_type = Psk.Wedge32
-
-            self.write_section(fp, b'VTXW0000', wedge_type, self.psk.wedges)
-            self.write_section(fp, b'FACE0000', Psk.Face, self.psk.faces)
-            self.write_section(fp, b'MATT0000', Psk.Material, self.psk.materials)
-            self.write_section(fp, b'REFSKELT', Psk.Bone, self.psk.bones)
-            self.write_section(fp, b'RAWWEIGHTS', Psk.Weight, self.psk.weights)

io_export_psk_psa/psk/operator.py

@@ -1,36 +0,0 @@
-from bpy.types import Operator
-from bpy_extras.io_utils import ExportHelper
-from bpy.props import StringProperty, BoolProperty, FloatProperty
-from .builder import PskBuilder
-from .exporter import PskExporter
-
-
-class PskExportOperator(Operator, ExportHelper):
-    bl_idname = 'export.psk'
-    bl_label = 'Export'
-    __doc__ = 'PSK Exporter (.psk)'
-    filename_ext = '.psk'
-    filter_glob: StringProperty(default='*.psk', options={'HIDDEN'})
-
-    filepath: StringProperty(
-        name='File Path',
-        description='File path used for exporting the PSK file',
-        maxlen=1024,
-        default='')
-
-    def invoke(self, context, event):
-        try:
-            PskBuilder.get_input_objects(context)
-        except RuntimeError as e:
-            self.report({'ERROR_INVALID_CONTEXT'}, str(e))
-            return {'CANCELLED'}
-
-        context.window_manager.fileselect_add(self)
-        return {'RUNNING_MODAL'}
-
-    def execute(self, context):
-        builder = PskBuilder()
-        psk = builder.build(context)
-        exporter = PskExporter(psk)
-        exporter.export(self.filepath)
-        return {'FINISHED'}

io_scene_psk_psa/__init__.py

@@ -0,0 +1,93 @@
+bl_info = {
+    "name": "PSK/PSA Importer/Exporter",
+    "author": "Colin Basnett",
+    "version": (3, 0, 0),
+    "blender": (2, 80, 0),
+    # "location": "File > Export > PSK Export (.psk)",
+    "description": "PSK/PSA Import/Export (.psk/.psa)",
+    "warning": "",
+    "doc_url": "https://github.com/DarklightGames/io_scene_psk_psa",
+    "tracker_url": "https://github.com/DarklightGames/io_scene_psk_psa/issues",
+    "category": "Import-Export"
+}
+
+if 'bpy' in locals():
+    import importlib
+
+    importlib.reload(psx_data)
+    importlib.reload(psx_helpers)
+    importlib.reload(psx_types)
+    importlib.reload(psk_data)
+    importlib.reload(psk_builder)
+    importlib.reload(psk_exporter)
+    importlib.reload(psk_importer)
+    importlib.reload(psk_reader)
+    importlib.reload(psa_data)
+    importlib.reload(psa_builder)
+    importlib.reload(psa_exporter)
+    importlib.reload(psa_reader)
+    importlib.reload(psa_importer)
+else:
+    # if i remove this line, it can be enabled just fine
+    from . import data as psx_data
+    from . import helpers as psx_helpers
+    from . import types as psx_types
+    from .psk import data as psk_data
+    from .psk import builder as psk_builder
+    from .psk import exporter as psk_exporter
+    from .psk import reader as psk_reader
+    from .psk import importer as psk_importer
+    from .psa import data as psa_data
+    from .psa import builder as psa_builder
+    from .psa import exporter as psa_exporter
+    from .psa import reader as psa_reader
+    from .psa import importer as psa_importer
+
+import bpy
+from bpy.props import PointerProperty
+
+classes = (psx_types.classes +
+           psk_importer.classes +
+           psk_exporter.classes +
+           psa_exporter.classes +
+           psa_importer.classes)
+
+
+def psk_export_menu_func(self, context):
+    self.layout.operator(psk_exporter.PskExportOperator.bl_idname, text='Unreal PSK (.psk)')
+
+
+def psk_import_menu_func(self, context):
+    self.layout.operator(psk_importer.PskImportOperator.bl_idname, text='Unreal PSK (.psk/.pskx)')
+
+
+def psa_export_menu_func(self, context):
+    self.layout.operator(psa_exporter.PsaExportOperator.bl_idname, text='Unreal PSA (.psa)')
+
+
+def register():
+    for cls in classes:
+        bpy.utils.register_class(cls)
+    bpy.types.TOPBAR_MT_file_export.append(psk_export_menu_func)
+    bpy.types.TOPBAR_MT_file_import.append(psk_import_menu_func)
+    bpy.types.TOPBAR_MT_file_export.append(psa_export_menu_func)
+    bpy.types.Scene.psa_import = PointerProperty(type=psa_importer.PsaImportPropertyGroup)
+    bpy.types.Scene.psk_import = PointerProperty(type=psk_importer.PskImportPropertyGroup)
+    bpy.types.Scene.psa_export = PointerProperty(type=psa_exporter.PsaExportPropertyGroup)
+    bpy.types.Scene.psk_export = PointerProperty(type=psk_exporter.PskExportPropertyGroup)
+
+
+def unregister():
+    del bpy.types.Scene.psa_import
+    del bpy.types.Scene.psk_import
+    del bpy.types.Scene.psa_export
+    del bpy.types.Scene.psk_export
+    bpy.types.TOPBAR_MT_file_export.remove(psk_export_menu_func)
+    bpy.types.TOPBAR_MT_file_import.remove(psk_import_menu_func)
+    bpy.types.TOPBAR_MT_file_export.remove(psa_export_menu_func)
+    for cls in reversed(classes):
+        bpy.utils.unregister_class(cls)
+
+
+if __name__ == '__main__':
+    register()

io_scene_psk_psa/data.py

@@ -0,0 +1,95 @@
+from ctypes import *
+from typing import Tuple
+
+
+class Color(Structure):
+    _fields_ = [
+        ('r', c_ubyte),
+        ('g', c_ubyte),
+        ('b', c_ubyte),
+        ('a', c_ubyte),
+    ]
+
+    def __iter__(self):
+        yield self.r
+        yield self.g
+        yield self.b
+        yield self.a
+
+    def __eq__(self, other):
+        return all(map(lambda x: x[0] == x[1], zip(self, other)))
+
+    def __repr__(self):
+        return repr(tuple(self))
+
+    def normalized(self) -> Tuple:
+        return tuple(map(lambda x: x / 255.0, iter(self)))
+
+
+class Vector2(Structure):
+    _fields_ = [
+        ('x', c_float),
+        ('y', c_float),
+    ]
+
+    def __iter__(self):
+        yield self.x
+        yield self.y
+
+    def __repr__(self):
+        return repr(tuple(self))
+
+
+class Vector3(Structure):
+    _fields_ = [
+        ('x', c_float),
+        ('y', c_float),
+        ('z', c_float),
+    ]
+
+    def __iter__(self):
+        yield self.x
+        yield self.y
+        yield self.z
+
+    def __repr__(self):
+        return repr(tuple(self))
+
+    @classmethod
+    def zero(cls):
+        return Vector3(0, 0, 0)
+
+
+class Quaternion(Structure):
+    _fields_ = [
+        ('x', c_float),
+        ('y', c_float),
+        ('z', c_float),
+        ('w', c_float),
+    ]
+
+    def __iter__(self):
+        yield self.w
+        yield self.x
+        yield self.y
+        yield self.z
+
+    def __repr__(self):
+        return repr(tuple(self))
+
+    @classmethod
+    def identity(cls):
+        return Quaternion(0, 0, 0, 1)
+
+
+class Section(Structure):
+    _fields_ = [
+        ('name', c_char * 20),
+        ('type_flags', c_int32),
+        ('data_size', c_int32),
+        ('data_count', c_int32)
+    ]
+
+    def __init__(self, *args, **kw):
+        super().__init__(*args, **kw)
+        self.type_flags = 1999801

io_scene_psk_psa/helpers.py

@@ -0,0 +1,158 @@
+import datetime
+from collections import Counter
+from typing import List
+
+from bpy.types import NlaStrip
+
+
+class Timer:
+    def __enter__(self):
+        self.start = datetime.datetime.now()
+        self.interval = None
+        return self
+
+    def __exit__(self, *args):
+        self.end = datetime.datetime.now()
+        self.interval = self.end - self.start
+
+    @property
+    def duration(self):
+        if self.interval is not None:
+            return self.interval
+        else:
+            return datetime.datetime.now() - self.start
+
+
+def rgb_to_srgb(c):
+    if c > 0.0031308:
+        return 1.055 * (pow(c, (1.0 / 2.4))) - 0.055
+    else:
+        return 12.92 * c
+
+
+def get_nla_strips_ending_at_frame(object, frame) -> List[NlaStrip]:
+    if object is None or object.animation_data is None:
+        return []
+    strips = []
+    for nla_track in object.animation_data.nla_tracks:
+        for strip in nla_track.strips:
+            if strip.frame_end == frame:
+                strips.append(strip)
+    return strips
+
+
+def get_nla_strips_in_timeframe(object, frame_min, frame_max) -> List[NlaStrip]:
+    if object is None or object.animation_data is None:
+        return []
+    strips = []
+    for nla_track in object.animation_data.nla_tracks:
+        if nla_track.mute:
+            continue
+        for strip in nla_track.strips:
+            if (strip.frame_start < frame_min and strip.frame_end > frame_max) or \
+                    (frame_min <= strip.frame_start < frame_max) or \
+                    (frame_min < strip.frame_end <= frame_max):
+                strips.append(strip)
+    return strips
+
+
+def populate_bone_group_list(armature_object, bone_group_list):
+    bone_group_list.clear()
+
+    if armature_object and armature_object.pose:
+        bone_group_counts = Counter(map(lambda x: x.bone_group, armature_object.pose.bones))
+
+        item = bone_group_list.add()
+        item.name = 'Unassigned'
+        item.index = -1
+        item.count = 0 if None not in bone_group_counts else bone_group_counts[None]
+        item.is_selected = True
+
+        for bone_group_index, bone_group in enumerate(armature_object.pose.bone_groups):
+            item = bone_group_list.add()
+            item.name = bone_group.name
+            item.index = bone_group_index
+            item.count = 0 if bone_group not in bone_group_counts else bone_group_counts[bone_group]
+            item.is_selected = True
+
+
+def get_psa_sequence_name(action, should_use_original_sequence_name):
+    if should_use_original_sequence_name and 'psa_sequence_name' in action:
+        return action['psa_sequence_name']
+    else:
+        return action.name
+
+
+def get_export_bone_names(armature_object, bone_filter_mode, bone_group_indices: List[int]) -> List[str]:
+    """
+    Returns a sorted list of bone indices that should be exported for the given bone filter mode and bone groups.
+
+    Note that the ancestors of bones within the bone groups will also be present in the returned list.
+
+    :param armature_object: Blender object with type 'ARMATURE'
+    :param bone_filter_mode: One of ['ALL', 'BONE_GROUPS']
+    :param bone_group_indices: List of bone group indices to be exported.
+    :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')
+
+    bones = armature_object.data.bones
+    pose_bones = armature_object.pose.bones
+    bone_names = [x.name for x in bones]
+
+    # Get a list of the bone indices that we are explicitly including.
+    bone_index_stack = []
+    is_exporting_none_bone_groups = -1 in bone_group_indices
+    for bone_index, pose_bone in enumerate(pose_bones):
+        if bone_filter_mode == 'ALL' or \
+                (pose_bone.bone_group is None and is_exporting_none_bone_groups) or \
+                (pose_bone.bone_group is not None and pose_bone.bone_group_index in bone_group_indices):
+            bone_index_stack.append((bone_index, None))
+
+    # For each bone that is explicitly being added, recursively walk up the hierarchy and ensure that all of
+    # those ancestor bone indices are also in the list.
+    bone_indices = dict()
+    while len(bone_index_stack) > 0:
+        bone_index, instigator_bone_index = bone_index_stack.pop()
+        bone = bones[bone_index]
+        if bone.parent is not None:
+            parent_bone_index = bone_names.index(bone.parent.name)
+            if parent_bone_index not in bone_indices:
+                bone_index_stack.append((parent_bone_index, bone_index))
+        bone_indices[bone_index] = instigator_bone_index
+
+    # Sort the bone index list in-place.
+    bone_indices = [(x[0], x[1]) for x in bone_indices.items()]
+    bone_indices.sort(key=lambda x: x[0])
+
+    # Split out the bone indices and the instigator bone names into separate lists.
+    # We use the bone names for the return values because the bone name is a more universal way of referencing them.
+    # For example, users of this function may modify bone lists, which would invalidate the indices and require a
+    # index mapping scheme to resolve it. Using strings is more comfy and results in less code downstream.
+    instigator_bone_names = [bones[x[1]].name if x[1] is not None else None for x in bone_indices]
+    bone_names = [bones[x[0]].name for x in bone_indices]
+
+    # Ensure that the hierarchy we are sending back has a single root bone.
+    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:
+        # There is more than one root bone.
+        # Print out why each root bone was included by linking it to one of the explicitly included bones.
+        root_bone_names = [bone.name for bone in root_bones]
+        for root_bone_name in root_bone_names:
+            bone_name = root_bone_name
+            while True:
+                # Traverse the instigator chain until the end to find the true instigator bone.
+                # TODO: in future, it would be preferential to have a readout of *all* instigator bones.
+                instigator_bone_name = instigator_bone_names[bone_names.index(bone_name)]
+                if instigator_bone_name is None:
+                    print(f'Root bone "{root_bone_name}" was included because {bone_name} was marked for export')
+                    break
+                bone_name = instigator_bone_name
+
+        raise RuntimeError('Exported bone hierarchy must have a single root bone.\n'
+                           f'The bone hierarchy marked for export has {len(root_bones)} root bones: {root_bone_names}.\n'
+                           f'Additional debugging information has been written to the console.')
+
+    return bone_names

io_scene_psk_psa/psa/builder.py

@@ -0,0 +1,283 @@
+from typing import Dict, Iterable
+
+from bpy.types import Action
+
+from .data import *
+from ..helpers import *
+
+
+class PsaBuilderOptions(object):
+    def __init__(self):
+        self.fps_source = 'SCENE'
+        self.fps_custom = 30.0
+        self.sequence_source = 'ACTIONS'
+        self.actions = []
+        self.marker_names = []
+        self.bone_filter_mode = 'ALL'
+        self.bone_group_indices = []
+        self.should_use_original_sequence_names = False
+        self.should_trim_timeline_marker_sequences = True
+        self.sequence_name_prefix = ''
+        self.sequence_name_suffix = ''
+
+
+class PsaBuilderPerformance:
+    def __init__(self):
+        self.frame_set_duration = datetime.timedelta()
+        self.key_build_duration = datetime.timedelta()
+        self.key_add_duration = datetime.timedelta()
+
+
+class PsaBuilder(object):
+    def __init__(self):
+        pass
+
+    def get_sequence_fps(self, context, options: PsaBuilderOptions, actions: Iterable[Action]) -> float:
+        if options.fps_source == 'SCENE':
+            return context.scene.render.fps
+        if options.fps_source == 'CUSTOM':
+            return options.fps_custom
+        elif options.fps_source == 'ACTION_METADATA':
+            # Get the minimum value of action metadata FPS values.
+            fps_list = []
+            for action in filter(lambda x: 'psa_sequence_fps' in x, actions):
+                fps = action['psa_sequence_fps']
+                if type(fps) == int or type(fps) == float:
+                    fps_list.append(fps)
+            if len(fps_list) > 0:
+                return min(fps_list)
+            else:
+                # No valid action metadata to use, fallback to scene FPS
+                return context.scene.render.fps
+        else:
+            raise RuntimeError(f'Invalid FPS source "{options.fps_source}"')
+
+    def build(self, context, options: PsaBuilderOptions) -> Psa:
+        performance = PsaBuilderPerformance()
+        active_object = context.view_layer.objects.active
+
+        if active_object.type != 'ARMATURE':
+            raise RuntimeError('Selected object must be an Armature')
+
+        armature = active_object
+
+        if armature.animation_data is None:
+            raise RuntimeError('No animation data for armature')
+
+        # Ensure that we actually have items that we are going to be exporting.
+        if options.sequence_source == 'ACTIONS' and len(options.actions) == 0:
+            raise RuntimeError('No actions were selected for export')
+        elif options.sequence_source == 'TIMELINE_MARKERS' and len(options.marker_names) == 0:
+            raise RuntimeError('No timeline markers were selected for export')
+
+        psa = Psa()
+
+        bones = list(armature.data.bones)
+
+        # The order of the armature bones and the pose bones is not guaranteed to be the same.
+        # As 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]
+        pose_bones = [(bone_names.index(bone.name), bone) for bone in armature.pose.bones]
+        pose_bones.sort(key=lambda x: x[0])
+        pose_bones = [x[1] for x in pose_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, options.bone_filter_mode, options.bone_group_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]
+        pose_bones = [pose_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')
+
+        # Build list of PSA bones.
+        for bone in bones:
+            psa_bone = Psa.Bone()
+            psa_bone.name = bytes(bone.name, encoding='utf-8')
+
+            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 = -1
+
+            if bone.parent is not None:
+                rotation = bone.matrix.to_quaternion()
+                rotation.x = -rotation.x
+                rotation.y = -rotation.y
+                rotation.z = -rotation.z
+                quat_parent = bone.parent.matrix.to_quaternion().inverted()
+                parent_head = quat_parent @ bone.parent.head
+                parent_tail = quat_parent @ bone.parent.tail
+                location = (parent_tail - parent_head) + bone.head
+            else:
+                location = armature.matrix_local @ bone.head
+                rot_matrix = bone.matrix @ armature.matrix_local.to_3x3()
+                rotation = rot_matrix.to_quaternion()
+
+            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)
+
+        # Populate the export sequence list.
+        class NlaState:
+            def __init__(self):
+                self.frame_min = 0
+                self.frame_max = 0
+                self.action = None
+
+        class ExportSequence:
+            def __init__(self):
+                self.name = ''
+                self.nla_state = NlaState()
+                self.fps = 30.0
+
+        export_sequences = []
+
+        if options.sequence_source == 'ACTIONS':
+            for action in options.actions:
+                if len(action.fcurves) == 0:
+                    continue
+                export_sequence = ExportSequence()
+                export_sequence.nla_state.action = action
+                export_sequence.name = get_psa_sequence_name(action, options.should_use_original_sequence_names)
+                frame_min, frame_max = [int(x) for x in action.frame_range]
+                export_sequence.nla_state.frame_min = frame_min
+                export_sequence.nla_state.frame_max = frame_max
+                export_sequence.fps = self.get_sequence_fps(context, options, [action])
+                export_sequences.append(export_sequence)
+            pass
+        elif options.sequence_source == 'TIMELINE_MARKERS':
+            sequence_frame_ranges = self.get_timeline_marker_sequence_frame_ranges(armature, context, options)
+
+            for name, (frame_min, frame_max) in sequence_frame_ranges.items():
+                export_sequence = ExportSequence()
+                export_sequence.name = name
+                export_sequence.nla_state.action = None
+                export_sequence.nla_state.frame_min = frame_min
+                export_sequence.nla_state.frame_max = frame_max
+                nla_strips_actions = set(
+                    map(lambda x: x.action, get_nla_strips_in_timeframe(active_object, frame_min, frame_max)))
+                export_sequence.fps = self.get_sequence_fps(context, options, nla_strips_actions)
+                export_sequences.append(export_sequence)
+        else:
+            raise ValueError(f'Unhandled sequence source: {options.sequence_source}')
+
+        # Add prefixes and suffices to the names of the export sequences and strip whitespace.
+        for export_sequence in export_sequences:
+            export_sequence.name = f'{options.sequence_name_prefix}{export_sequence.name}{options.sequence_name_suffix}'.strip()
+
+        # Now build the PSA sequences.
+        # We actually alter the timeline frame and simply record the resultant pose bone matrices.
+        frame_start_index = 0
+
+        for export_sequence in export_sequences:
+            armature.animation_data.action = export_sequence.nla_state.action
+            context.view_layer.update()
+
+            psa_sequence = Psa.Sequence()
+
+            frame_min = export_sequence.nla_state.frame_min
+            frame_max = export_sequence.nla_state.frame_max
+            frame_count = frame_max - frame_min + 1
+
+            psa_sequence.name = bytes(export_sequence.name, encoding='windows-1252')
+            psa_sequence.frame_count = frame_count
+            psa_sequence.frame_start_index = frame_start_index
+            psa_sequence.fps = export_sequence.fps
+
+            frame_count = frame_max - frame_min + 1
+
+            for frame in range(frame_count):
+                with Timer() as t:
+                    context.scene.frame_set(frame_min + frame)
+                performance.frame_set_duration += t.duration
+
+                for pose_bone in pose_bones:
+                    with Timer() as t:
+                        key = Psa.Key()
+                        pose_bone_matrix = pose_bone.matrix
+
+                        if pose_bone.parent is not None:
+                            pose_bone_parent_matrix = pose_bone.parent.matrix
+                            pose_bone_matrix = pose_bone_parent_matrix.inverted() @ pose_bone_matrix
+
+                        location = pose_bone_matrix.to_translation()
+                        rotation = pose_bone_matrix.to_quaternion().normalized()
+
+                        if pose_bone.parent is not None:
+                            rotation.x = -rotation.x
+                            rotation.y = -rotation.y
+                            rotation.z = -rotation.z
+
+                        key.location.x = location.x
+                        key.location.y = location.y
+                        key.location.z = location.z
+                        key.rotation.x = rotation.x
+                        key.rotation.y = rotation.y
+                        key.rotation.z = rotation.z
+                        key.rotation.w = rotation.w
+                        key.time = 1.0 / psa_sequence.fps
+                    performance.key_build_duration += t.duration
+
+                    with Timer() as t:
+                        psa.keys.append(key)
+                    performance.key_add_duration += t.duration
+
+                psa_sequence.bone_count = len(pose_bones)
+                psa_sequence.track_time = frame_count
+
+            frame_start_index += frame_count
+
+            psa.sequences[export_sequence.name] = psa_sequence
+
+        return psa
+
+    def get_timeline_marker_sequence_frame_ranges(self, object, context, options: PsaBuilderOptions) -> 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))
+        sorted_timeline_marker_names = list(map(lambda x: x.name, sorted_timeline_markers))
+
+        for marker_name in options.marker_names:
+            marker = context.scene.timeline_markers[marker_name]
+            frame_min = marker.frame
+            # Determine the final frame of the sequence based on the next marker.
+            # If no subsequent marker exists, use the maximum frame_end from all NLA strips.
+            marker_index = sorted_timeline_marker_names.index(marker_name)
+            next_marker_index = marker_index + 1
+            frame_max = 0
+            if next_marker_index < len(sorted_timeline_markers):
+                # There is a next marker. Use that next marker's frame position as the last frame of this sequence.
+                frame_max = sorted_timeline_markers[next_marker_index].frame
+                if options.should_trim_timeline_marker_sequences:
+                    nla_strips = get_nla_strips_in_timeframe(object, marker.frame, frame_max)
+                    frame_max = min(frame_max, max(map(lambda nla_strip: nla_strip.frame_end, nla_strips)))
+                    frame_min = max(frame_min, min(map(lambda nla_strip: nla_strip.frame_start, nla_strips)))
+            else:
+                # There is no next marker.
+                # Find the final frame of all the NLA strips and use that as the last frame of this sequence.
+                for nla_track in object.animation_data.nla_tracks:
+                    if nla_track.mute:
+                        continue
+                    for strip in nla_track.strips:
+                        frame_max = max(frame_max, strip.frame_end)
+
+            if frame_min == frame_max:
+                continue
+
+            sequence_frame_ranges[marker_name] = int(frame_min), int(frame_max)
+
+        return sequence_frame_ranges

io_scene_psk_psa/psa/data.py

@@ -1,9 +1,16 @@
+import typing
+from collections import OrderedDict
 from typing import List
+
 from ..data import *
 
+"""
+Note that keys are not stored within the Psa object.
+Use the PsaReader::get_sequence_keys to get a the keys for a sequence.
+"""
+
 
 class Psa(object):
-
     class Bone(Structure):
         _fields_ = [
             ('name', c_char * 64),
@@ -22,7 +29,7 @@ class Psa(object):
             ('bone_count', c_int32),
             ('root_include', c_int32),
             ('compression_style', c_int32),
-            ('key_quotum', c_int32),  # what the fuck is a quotum
+            ('key_quotum', c_int32),
             ('key_reduction', c_float),
             ('track_time', c_float),
             ('fps', c_float),
@@ -38,7 +45,20 @@ class Psa(object):
             ('time', c_float)
         ]
 
+        @property
+        def data(self):
+            yield self.rotation.w
+            yield self.rotation.x
+            yield self.rotation.y
+            yield self.rotation.z
+            yield self.location.x
+            yield self.location.y
+            yield self.location.z
+
+        def __repr__(self) -> str:
+            return repr((self.location, self.rotation, self.time))
+
     def __init__(self):
         self.bones: List[Psa.Bone] = []
-        self.sequences: List[Psa.Sequence] = []
+        self.sequences: typing.OrderedDict[Psa.Sequence] = OrderedDict()
         self.keys: List[Psa.Key] = []

io_scene_psk_psa/psa/exporter.py

@@ -0,0 +1,499 @@
+import fnmatch
+import re
+import sys
+from collections import Counter
+from typing import Type
+
+import bpy
+from bpy.props import BoolProperty, CollectionProperty, EnumProperty, FloatProperty, IntProperty, PointerProperty, \
+    StringProperty
+from bpy.types import Action, Operator, PropertyGroup, UIList
+from bpy_extras.io_utils import ExportHelper
+
+from .builder import PsaBuilder, PsaBuilderOptions
+from .data import *
+from ..helpers import *
+from ..types import BoneGroupListItem
+
+
+class PsaExporter(object):
+    def __init__(self, psa: Psa):
+        self.psa: Psa = psa
+
+    # This method is shared by both PSA/K file formats, move this?
+    @staticmethod
+    def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
+        section = Section()
+        section.name = name
+        if data_type is not None and data is not None:
+            section.data_size = sizeof(data_type)
+            section.data_count = len(data)
+        fp.write(section)
+        if data is not None:
+            for datum in data:
+                fp.write(datum)
+
+    def export(self, path: str):
+        with open(path, 'wb') as fp:
+            self.write_section(fp, b'ANIMHEAD')
+            self.write_section(fp, b'BONENAMES', Psa.Bone, self.psa.bones)
+            self.write_section(fp, b'ANIMINFO', Psa.Sequence, list(self.psa.sequences.values()))
+            self.write_section(fp, b'ANIMKEYS', Psa.Key, self.psa.keys)
+
+
+class PsaExportActionListItem(PropertyGroup):
+    action: PointerProperty(type=Action)
+    name: StringProperty()
+    is_selected: BoolProperty(default=False)
+
+
+class PsaExportTimelineMarkerListItem(PropertyGroup):
+    marker_index: IntProperty()
+    name: StringProperty()
+    is_selected: BoolProperty(default=True)
+
+
+def update_action_names(context):
+    pg = context.scene.psa_export
+    for item in pg.action_list:
+        action = item.action
+        item.action_name = get_psa_sequence_name(action, pg.should_use_original_sequence_names)
+
+
+def should_use_original_sequence_names_updated(_, context):
+    update_action_names(context)
+
+
+class PsaExportPropertyGroup(PropertyGroup):
+    sequence_source: EnumProperty(
+        name='Source',
+        options=set(),
+        description='',
+        items=(
+            ('ACTIONS', 'Actions', 'Sequences will be exported using actions', 'ACTION', 0),
+            ('TIMELINE_MARKERS', 'Timeline Markers', 'Sequences will be exported using timeline markers', 'MARKER_HLT',
+             1),
+        )
+    )
+    fps_source: EnumProperty(
+        name='FPS Source',
+        options=set(),
+        description='',
+        items=(
+            ('SCENE', 'Scene', '', 'SCENE_DATA', 0),
+            ('ACTION_METADATA', 'Action Metadata',
+             'The frame rate will be determined by action\'s "psa_sequence_fps" custom property, if it exists. If the Sequence Source is Timeline Markers, the lowest value of all contributing actions will be used. If no metadata is available, the scene\'s frame rate will be used.',
+             'PROPERTIES', 1),
+            ('CUSTOM', 'Custom', '', 2)
+        )
+    )
+    fps_custom: FloatProperty(default=30.0, min=sys.float_info.epsilon, soft_min=1.0, options=set(), step=100,
+                              soft_max=60.0)
+    action_list: CollectionProperty(type=PsaExportActionListItem)
+    action_list_index: IntProperty(default=0)
+    marker_list: CollectionProperty(type=PsaExportTimelineMarkerListItem)
+    marker_list_index: IntProperty(default=0)
+    bone_filter_mode: EnumProperty(
+        name='Bone Filter',
+        options=set(),
+        description='',
+        items=(
+            ('ALL', 'All', 'All bones will be exported.'),
+            ('BONE_GROUPS', 'Bone Groups', 'Only bones belonging to the selected bone groups and their ancestors will '
+                                           'be exported.'),
+        )
+    )
+    bone_group_list: CollectionProperty(type=BoneGroupListItem)
+    bone_group_list_index: IntProperty(default=0, name='', description='')
+    should_use_original_sequence_names: BoolProperty(
+        default=False,
+        name='Original Names',
+        options=set(),
+        update=should_use_original_sequence_names_updated,
+        description='If the action was imported from the PSA Import panel, the original name of the sequence will be '
+                    'used instead of the Blender action name',
+    )
+    should_trim_timeline_marker_sequences: BoolProperty(
+        default=True,
+        name='Trim Sequences',
+        options=set(),
+        description='Frames without NLA track information at the boundaries of timeline markers will be excluded from '
+                    'the exported sequences '
+    )
+    sequence_name_prefix: StringProperty(name='Prefix', options=set())
+    sequence_name_suffix: StringProperty(name='Suffix', options=set())
+    sequence_filter_name: StringProperty(default='', options={'TEXTEDIT_UPDATE'})
+    sequence_use_filter_invert: BoolProperty(default=False, options=set())
+    sequence_filter_asset: BoolProperty(default=False, name='Show assets',
+                                        description='Show actions that belong to an asset library', options=set())
+    sequence_use_filter_sort_reverse: BoolProperty(default=True, options=set())
+
+
+def is_bone_filter_mode_item_available(context, identifier):
+    if identifier == 'BONE_GROUPS':
+        obj = context.active_object
+        if not obj.pose or not obj.pose.bone_groups:
+            return False
+    return True
+
+
+class PsaExportOperator(Operator, ExportHelper):
+    bl_idname = 'psa_export.operator'
+    bl_label = 'Export'
+    bl_options = {'INTERNAL', 'UNDO'}
+    __doc__ = 'Export actions to PSA'
+    filename_ext = '.psa'
+    filter_glob: StringProperty(default='*.psa', options={'HIDDEN'})
+    filepath: StringProperty(
+        name='File Path',
+        description='File path used for exporting the PSA file',
+        maxlen=1024,
+        default='')
+
+    def __init__(self):
+        self.armature = None
+
+    def draw(self, context):
+        layout = self.layout
+        pg = context.scene.psa_export
+
+        # FPS
+        layout.prop(pg, 'fps_source', text='FPS')
+        if pg.fps_source == 'CUSTOM':
+            layout.prop(pg, 'fps_custom', text='Custom')
+
+        # SOURCE
+        layout.prop(pg, 'sequence_source', text='Source')
+
+        # SELECT ALL/NONE
+        row = layout.row(align=True)
+        row.label(text='Select')
+        row.operator(PsaExportActionsSelectAll.bl_idname, text='All', icon='CHECKBOX_HLT')
+        row.operator(PsaExportActionsDeselectAll.bl_idname, text='None', icon='CHECKBOX_DEHLT')
+
+        # ACTIONS
+        if pg.sequence_source == 'ACTIONS':
+            rows = max(3, min(len(pg.action_list), 10))
+
+            layout.template_list('PSA_UL_ExportActionList', '', pg, 'action_list', pg, 'action_list_index', rows=rows)
+
+            col = layout.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(pg, 'should_use_original_sequence_names')
+            col.prop(pg, 'sequence_name_prefix')
+            col.prop(pg, 'sequence_name_suffix')
+
+        elif pg.sequence_source == 'TIMELINE_MARKERS':
+            rows = max(3, min(len(pg.marker_list), 10))
+            layout.template_list('PSA_UL_ExportTimelineMarkerList', '', pg, 'marker_list', pg, 'marker_list_index',
+                                 rows=rows)
+
+            col = layout.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(pg, 'should_trim_timeline_marker_sequences')
+            col.prop(pg, 'sequence_name_prefix')
+            col.prop(pg, 'sequence_name_suffix')
+
+        # Determine if there is going to be a naming conflict and display an error, if so.
+        selected_items = [x for x in pg.action_list if x.is_selected]
+        action_names = [x.name for x in selected_items]
+        action_name_counts = Counter(action_names)
+        for action_name, count in action_name_counts.items():
+            if count > 1:
+                layout.label(text=f'Duplicate action: {action_name}', icon='ERROR')
+                break
+
+        layout.separator()
+
+        # BONES
+        row = layout.row(align=True)
+        row.prop(pg, 'bone_filter_mode', text='Bones')
+
+        if pg.bone_filter_mode == 'BONE_GROUPS':
+            row = layout.row(align=True)
+            row.label(text='Select')
+            row.operator(PsaExportBoneGroupsSelectAll.bl_idname, text='All', icon='CHECKBOX_HLT')
+            row.operator(PsaExportBoneGroupsDeselectAll.bl_idname, text='None', icon='CHECKBOX_DEHLT')
+            rows = max(3, min(len(pg.bone_group_list), 10))
+            layout.template_list('PSX_UL_BoneGroupList', '', pg, 'bone_group_list', pg, 'bone_group_list_index',
+                                 rows=rows)
+
+    def should_action_be_selected_by_default(self, action):
+        return action is not None and action.asset_data is None
+
+    def is_action_for_armature(self, action):
+        if len(action.fcurves) == 0:
+            return False
+        bone_names = set([x.name for x in self.armature.data.bones])
+        for fcurve in action.fcurves:
+            match = re.match(r'pose\.bones\["(.+)"\].\w+', fcurve.data_path)
+            if not match:
+                continue
+            bone_name = match.group(1)
+            if bone_name in bone_names:
+                return True
+        return False
+
+    def invoke(self, context, event):
+        pg = context.scene.psa_export
+
+        if context.view_layer.objects.active is None:
+            self.report({'ERROR_INVALID_CONTEXT'}, 'An armature must be selected')
+            return {'CANCELLED'}
+
+        if context.view_layer.objects.active.type != 'ARMATURE':
+            self.report({'ERROR_INVALID_CONTEXT'}, 'The selected object must be an armature.')
+            return {'CANCELLED'}
+
+        self.armature = context.view_layer.objects.active
+
+        # Populate actions list.
+        pg.action_list.clear()
+        for action in bpy.data.actions:
+            if not self.is_action_for_armature(action):
+                continue
+            item = pg.action_list.add()
+            item.action = action
+            item.name = action.name
+            item.is_selected = self.should_action_be_selected_by_default(action)
+
+        update_action_names(context)
+
+        # Populate timeline markers list.
+        pg.marker_list.clear()
+        for marker in context.scene.timeline_markers:
+            item = pg.marker_list.add()
+            item.name = marker.name
+
+        if len(pg.action_list) == 0 and len(pg.marker_list) == 0:
+            # If there are no actions at all, we have nothing to export, so just cancel the operation.
+            self.report({'ERROR_INVALID_CONTEXT'}, 'There are no actions or timeline markers to export.')
+            return {'CANCELLED'}
+
+        # Populate bone groups list.
+        populate_bone_group_list(self.armature, pg.bone_group_list)
+
+        context.window_manager.fileselect_add(self)
+
+        return {'RUNNING_MODAL'}
+
+    def execute(self, context):
+        pg = context.scene.psa_export
+
+        actions = [x.action for x in pg.action_list if x.is_selected]
+        marker_names = [x.name for x in pg.marker_list if x.is_selected]
+
+        options = PsaBuilderOptions()
+        options.fps_source = pg.fps_source
+        options.fps_custom = pg.fps_custom
+        options.sequence_source = pg.sequence_source
+        options.actions = actions
+        options.marker_names = marker_names
+        options.bone_filter_mode = pg.bone_filter_mode
+        options.bone_group_indices = [x.index for x in pg.bone_group_list if x.is_selected]
+        options.should_use_original_sequence_names = pg.should_use_original_sequence_names
+        options.should_trim_timeline_marker_sequences = pg.should_trim_timeline_marker_sequences
+        options.sequence_name_prefix = pg.sequence_name_prefix
+        options.sequence_name_suffix = pg.sequence_name_suffix
+
+        builder = PsaBuilder()
+
+        try:
+            psa = builder.build(context, options)
+        except RuntimeError as e:
+            self.report({'ERROR_INVALID_CONTEXT'}, str(e))
+            return {'CANCELLED'}
+
+        exporter = PsaExporter(psa)
+        exporter.export(self.filepath)
+        return {'FINISHED'}
+
+
+class PSA_UL_ExportTimelineMarkerList(UIList):
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+        layout.prop(item, 'is_selected', icon_only=True, text=item.name)
+
+    def filter_items(self, context, data, property):
+        pg = context.scene.psa_export
+        sequences = getattr(data, property)
+        flt_flags = filter_sequences(pg, sequences)
+        flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(sequences, 'name')
+        return flt_flags, flt_neworder
+
+
+def filter_sequences(pg: PsaExportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[int]:
+    bitflag_filter_item = 1 << 30
+    flt_flags = [bitflag_filter_item] * len(sequences)
+
+    if pg.sequence_filter_name is not None:
+        # Filter name is non-empty.
+        for i, sequence in enumerate(sequences):
+            if not fnmatch.fnmatch(sequence.name, f'*{pg.sequence_filter_name}*'):
+                flt_flags[i] &= ~bitflag_filter_item
+
+    if not pg.sequence_filter_asset:
+        for i, sequence in enumerate(sequences):
+            if hasattr(sequence, 'action') and sequence.action.asset_data is not None:
+                flt_flags[i] &= ~bitflag_filter_item
+
+    if pg.sequence_use_filter_invert:
+        # Invert filter flags for all items.
+        for i, sequence in enumerate(sequences):
+            flt_flags[i] ^= bitflag_filter_item
+
+    return flt_flags
+
+
+def get_visible_sequences(pg: PsaExportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[
+    PsaExportActionListItem]:
+    visible_sequences = []
+    for i, flag in enumerate(filter_sequences(pg, sequences)):
+        if bool(flag & (1 << 30)):
+            visible_sequences.append(sequences[i])
+    return visible_sequences
+
+
+class PSA_UL_ExportActionList(UIList):
+
+    def __init__(self):
+        super(PSA_UL_ExportActionList, self).__init__()
+        # Show the filtering options by default.
+        self.use_filter_show = True
+
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+        layout.prop(item, 'is_selected', icon_only=True, text=item.name)
+        if item.action.asset_data is not None:
+            layout.label(text='', icon='ASSET_MANAGER')
+
+    def draw_filter(self, context, layout):
+        pg = context.scene.psa_export
+        row = layout.row()
+        subrow = row.row(align=True)
+        subrow.prop(pg, 'sequence_filter_name', text="")
+        subrow.prop(pg, 'sequence_use_filter_invert', text="", icon='ARROW_LEFTRIGHT')
+        subrow = row.row(align=True)
+        subrow.prop(pg, 'sequence_filter_asset', icon_only=True, icon='ASSET_MANAGER')
+        # subrow.prop(pg, 'sequence_use_filter_sort_reverse', text='', icon='SORT_ASC')
+
+    def filter_items(self, context, data, property):
+        pg = context.scene.psa_export
+        actions = getattr(data, property)
+        flt_flags = filter_sequences(pg, actions)
+        flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(actions, 'name')
+        return flt_flags, flt_neworder
+
+
+class PsaExportActionsSelectAll(Operator):
+    bl_idname = 'psa_export.sequences_select_all'
+    bl_label = 'Select All'
+    bl_description = 'Select all visible sequences'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def get_item_list(cls, context):
+        pg = context.scene.psa_export
+        if pg.sequence_source == 'ACTIONS':
+            return pg.action_list
+        elif pg.sequence_source == 'TIMELINE_MARKERS':
+            return pg.marker_list
+        return None
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_export
+        item_list = cls.get_item_list(context)
+        visible_sequences = get_visible_sequences(pg, item_list)
+        has_unselected_sequences = any(map(lambda item: not item.is_selected, visible_sequences))
+        return has_unselected_sequences
+
+    def execute(self, context):
+        pg = context.scene.psa_export
+        sequences = self.get_item_list(context)
+        for sequence in get_visible_sequences(pg, sequences):
+            sequence.is_selected = True
+        return {'FINISHED'}
+
+
+class PsaExportActionsDeselectAll(Operator):
+    bl_idname = 'psa_export.sequences_deselect_all'
+    bl_label = 'Deselect All'
+    bl_description = 'Deselect all visible sequences'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def get_item_list(cls, context):
+        pg = context.scene.psa_export
+        if pg.sequence_source == 'ACTIONS':
+            return pg.action_list
+        elif pg.sequence_source == 'TIMELINE_MARKERS':
+            return pg.marker_list
+        return None
+
+    @classmethod
+    def poll(cls, context):
+        item_list = cls.get_item_list(context)
+        has_selected_items = any(map(lambda item: item.is_selected, item_list))
+        return len(item_list) > 0 and has_selected_items
+
+    def execute(self, context):
+        pg = context.scene.psa_export
+        item_list = self.get_item_list(context)
+        for sequence in get_visible_sequences(pg, item_list):
+            sequence.is_selected = False
+        return {'FINISHED'}
+
+
+class PsaExportBoneGroupsSelectAll(Operator):
+    bl_idname = 'psa_export.bone_groups_select_all'
+    bl_label = 'Select All'
+    bl_description = 'Select all bone groups'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_export
+        item_list = pg.bone_group_list
+        has_unselected_items = any(map(lambda action: not action.is_selected, item_list))
+        return len(item_list) > 0 and has_unselected_items
+
+    def execute(self, context):
+        pg = context.scene.psa_export
+        for item in pg.bone_group_list:
+            item.is_selected = True
+        return {'FINISHED'}
+
+
+class PsaExportBoneGroupsDeselectAll(Operator):
+    bl_idname = 'psa_export.bone_groups_deselect_all'
+    bl_label = 'Deselect All'
+    bl_description = 'Deselect all bone groups'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_export
+        item_list = pg.bone_group_list
+        has_selected_actions = any(map(lambda action: action.is_selected, item_list))
+        return len(item_list) > 0 and has_selected_actions
+
+    def execute(self, context):
+        pg = context.scene.psa_export
+        for action in pg.bone_group_list:
+            action.is_selected = False
+        return {'FINISHED'}
+
+
+classes = (
+    PsaExportActionListItem,
+    PsaExportTimelineMarkerListItem,
+    PsaExportPropertyGroup,
+    PsaExportOperator,
+    PSA_UL_ExportActionList,
+    PSA_UL_ExportTimelineMarkerList,
+    PsaExportActionsSelectAll,
+    PsaExportActionsDeselectAll,
+    PsaExportBoneGroupsSelectAll,
+    PsaExportBoneGroupsDeselectAll,
+)

io_scene_psk_psa/psa/importer.py

@@ -0,0 +1,638 @@
+import fnmatch
+import os
+import re
+from typing import List, Optional
+
+import bpy
+import numpy as np
+from bpy.props import StringProperty, BoolProperty, CollectionProperty, PointerProperty, IntProperty
+from bpy.types import Operator, UIList, PropertyGroup, Panel
+from bpy_extras.io_utils import ImportHelper
+from mathutils import Vector, Quaternion
+
+from .data import Psa
+from .reader import PsaReader
+
+
+class PsaImportOptions(object):
+    def __init__(self):
+        self.should_clean_keys = True
+        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 = ''
+
+
+class PsaImporter(object):
+    def __init__(self):
+        pass
+
+    def import_psa(self, psa_reader: PsaReader, armature_object, options: PsaImportOptions):
+        sequences = map(lambda x: psa_reader.sequences[x], options.sequence_names)
+        armature_data = armature_object.data
+
+        class ImportBone(object):
+            def __init__(self, psa_bone: Psa.Bone):
+                self.psa_bone: Psa.Bone = psa_bone
+                self.parent: Optional[ImportBone] = None
+                self.armature_bone = None
+                self.pose_bone = None
+                self.orig_loc: Vector = Vector()
+                self.orig_quat: Quaternion = Quaternion()
+                self.post_quat: Quaternion = Quaternion()
+                self.fcurves = []
+
+        def calculate_fcurve_data(import_bone: ImportBone, key_data: []):
+            # Convert world-space transforms to local-space transforms.
+            key_rotation = Quaternion(key_data[0:4])
+            key_location = Vector(key_data[4:])
+            q = import_bone.post_quat.copy()
+            q.rotate(import_bone.orig_quat)
+            quat = q
+            q = import_bone.post_quat.copy()
+            if import_bone.parent is None:
+                q.rotate(key_rotation.conjugated())
+            else:
+                q.rotate(key_rotation)
+            quat.rotate(q.conjugated())
+            loc = key_location - import_bone.orig_loc
+            loc.rotate(import_bone.post_quat.conjugated())
+            return quat.w, quat.x, quat.y, quat.z, loc.x, loc.y, loc.z
+
+        # Create an index mapping from bones in the PSA to bones in the target armature.
+        psa_to_armature_bone_indices = {}
+        armature_bone_names = [x.name for x in armature_data.bones]
+        psa_bone_names = []
+        for psa_bone_index, psa_bone in enumerate(psa_reader.bones):
+            psa_bone_name = psa_bone.name.decode('windows-1252')
+            psa_bone_names.append(psa_bone_name)
+            try:
+                psa_to_armature_bone_indices[psa_bone_index] = armature_bone_names.index(psa_bone_name)
+            except ValueError:
+                pass
+
+        # Report if there are missing bones in the target armature.
+        missing_bone_names = set(psa_bone_names).difference(set(armature_bone_names))
+        if len(missing_bone_names) > 0:
+            print(
+                f'The armature object \'{armature_object.name}\' is missing the following bones that exist in the PSA:')
+            print(list(sorted(missing_bone_names)))
+        del armature_bone_names
+
+        # Create intermediate bone data for import operations.
+        import_bones = []
+        import_bones_dict = dict()
+
+        for psa_bone_index, psa_bone in enumerate(psa_reader.bones):
+            bone_name = psa_bone.name.decode('windows-1252')
+            if psa_bone_index not in psa_to_armature_bone_indices:  # TODO: replace with bone_name in armature_data.bones
+                # PSA bone does not map to armature bone, skip it and leave an empty bone in its place.
+                import_bones.append(None)
+                continue
+            import_bone = ImportBone(psa_bone)
+            import_bone.armature_bone = armature_data.bones[bone_name]
+            import_bone.pose_bone = armature_object.pose.bones[bone_name]
+            import_bones_dict[bone_name] = import_bone
+            import_bones.append(import_bone)
+
+        for import_bone in filter(lambda x: x is not None, import_bones):
+            armature_bone = import_bone.armature_bone
+            if armature_bone.parent is not None and armature_bone.parent.name in psa_bone_names:
+                import_bone.parent = import_bones_dict[armature_bone.parent.name]
+            # Calculate the original location & rotation of each bone (in world-space maybe?)
+            if armature_bone.get('orig_quat') is not None:
+                # TODO: ideally we don't rely on bone auxiliary data like this, the non-aux data path is incorrect (animations are flipped 180 around Z)
+                import_bone.orig_quat = Quaternion(armature_bone['orig_quat'])
+                import_bone.orig_loc = Vector(armature_bone['orig_loc'])
+                import_bone.post_quat = Quaternion(armature_bone['post_quat'])
+            else:
+                if import_bone.parent is not None:
+                    import_bone.orig_loc = armature_bone.matrix_local.translation - armature_bone.parent.matrix_local.translation
+                    import_bone.orig_loc.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
+                    import_bone.orig_quat = armature_bone.matrix_local.to_quaternion()
+                    import_bone.orig_quat.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
+                    import_bone.orig_quat.conjugate()
+                else:
+                    import_bone.orig_loc = armature_bone.matrix_local.translation.copy()
+                    import_bone.orig_quat = armature_bone.matrix_local.to_quaternion()
+                import_bone.post_quat = import_bone.orig_quat.conjugated()
+
+        # Create and populate the data for new sequences.
+        actions = []
+        for sequence in sequences:
+            # Add the action.
+            sequence_name = sequence.name.decode('windows-1252')
+            action_name = options.action_name_prefix + sequence_name
+
+            if options.should_overwrite and action_name in bpy.data.actions:
+                action = bpy.data.actions[action_name]
+            else:
+                action = bpy.data.actions.new(name=action_name)
+
+            if options.should_write_keyframes:
+                # Remove existing f-curves (replace with action.fcurves.clear() in Blender 3.2)
+                while len(action.fcurves) > 0:
+                    action.fcurves.remove(action.fcurves[-1])
+
+                # Create f-curves for the rotation and location of each bone.
+                for psa_bone_index, armature_bone_index in psa_to_armature_bone_indices.items():
+                    import_bone = import_bones[psa_bone_index]
+                    pose_bone = import_bone.pose_bone
+                    rotation_data_path = pose_bone.path_from_id('rotation_quaternion')
+                    location_data_path = pose_bone.path_from_id('location')
+                    import_bone.fcurves = [
+                        action.fcurves.new(rotation_data_path, index=0, action_group=pose_bone.name),  # Qw
+                        action.fcurves.new(rotation_data_path, index=1, action_group=pose_bone.name),  # Qx
+                        action.fcurves.new(rotation_data_path, index=2, action_group=pose_bone.name),  # Qy
+                        action.fcurves.new(rotation_data_path, index=3, action_group=pose_bone.name),  # Qz
+                        action.fcurves.new(location_data_path, index=0, action_group=pose_bone.name),  # Lx
+                        action.fcurves.new(location_data_path, index=1, action_group=pose_bone.name),  # Ly
+                        action.fcurves.new(location_data_path, index=2, action_group=pose_bone.name),  # Lz
+                    ]
+
+                # Read the sequence data matrix from the PSA.
+                sequence_data_matrix = psa_reader.read_sequence_data_matrix(sequence_name)
+                keyframe_write_matrix = np.ones(sequence_data_matrix.shape, dtype=np.int8)
+
+                # Convert the sequence's data from world-space to local-space.
+                for bone_index, import_bone in enumerate(import_bones):
+                    if import_bone is None:
+                        continue
+                    for frame_index in range(sequence.frame_count):
+                        # This bone has writeable keyframes for this frame.
+                        key_data = sequence_data_matrix[frame_index, bone_index]
+                        # Calculate the local-space key data for the bone.
+                        sequence_data_matrix[frame_index, bone_index] = calculate_fcurve_data(import_bone, key_data)
+
+                # Clean the keyframe data. This is accomplished by writing zeroes to the write matrix when there is an
+                # insufficiently large change in the data from the last written frame.
+                if options.should_clean_keys:
+                    threshold = 0.001
+                    for bone_index, import_bone in enumerate(import_bones):
+                        if import_bone is None:
+                            continue
+                        for fcurve_index in range(len(import_bone.fcurves)):
+                            # Get all the keyframe data for the bone's f-curve data from the sequence data matrix.
+                            fcurve_frame_data = sequence_data_matrix[:, bone_index, fcurve_index]
+                            last_written_datum = 0
+                            for frame_index, datum in enumerate(fcurve_frame_data):
+                                # If the f-curve data is not different enough to the last written frame, un-mark this data for writing.
+                                if frame_index > 0 and abs(datum - last_written_datum) < threshold:
+                                    keyframe_write_matrix[frame_index, bone_index, fcurve_index] = 0
+                                else:
+                                    last_written_datum = datum
+
+                # Write the keyframes out!
+                for frame_index in range(sequence.frame_count):
+                    for bone_index, import_bone in enumerate(import_bones):
+                        if import_bone is None:
+                            continue
+                        bone_has_writeable_keyframes = any(keyframe_write_matrix[frame_index, bone_index])
+                        if bone_has_writeable_keyframes:
+                            # This bone has writeable keyframes for this frame.
+                            key_data = sequence_data_matrix[frame_index, bone_index]
+                            for fcurve, should_write, datum in zip(import_bone.fcurves,
+                                                                   keyframe_write_matrix[frame_index, bone_index],
+                                                                   key_data):
+                                if should_write:
+                                    fcurve.keyframe_points.insert(frame_index, datum, options={'FAST'})
+
+            # Write
+            if options.should_write_metadata:
+                action['psa_sequence_name'] = sequence_name
+                action['psa_sequence_fps'] = sequence.fps
+
+            action.use_fake_user = options.should_use_fake_user
+
+            actions.append(action)
+
+        # If the user specifies, store the new animations as strips on a non-contributing NLA track.
+        if options.should_stash:
+            if armature_object.animation_data is None:
+                armature_object.animation_data_create()
+            for action in actions:
+                nla_track = armature_object.animation_data.nla_tracks.new()
+                nla_track.name = action.name
+                nla_track.mute = True
+                nla_track.strips.new(name=action.name, start=0, action=action)
+
+
+class PsaImportActionListItem(PropertyGroup):
+    action_name: StringProperty(options=set())
+    is_selected: BoolProperty(default=False, options=set())
+
+
+def load_psa_file(context):
+    pg = context.scene.psa_import
+    pg.sequence_list.clear()
+    pg.psa.bones.clear()
+    pg.psa_error = ''
+    try:
+        # Read the file and populate the action list.
+        p = os.path.abspath(pg.psa_file_path)
+        psa_reader = PsaReader(p)
+        for sequence in psa_reader.sequences.values():
+            item = pg.sequence_list.add()
+            item.action_name = sequence.name.decode('windows-1252')
+        for psa_bone in psa_reader.bones:
+            item = pg.psa.bones.add()
+            item.bone_name = psa_bone.name.decode('windows-1252')
+    except Exception as e:
+        pg.psa_error = str(e)
+
+
+def on_psa_file_path_updated(property, context):
+    load_psa_file(context)
+
+
+class PsaBonePropertyGroup(PropertyGroup):
+    bone_name: StringProperty(options=set())
+
+
+class PsaDataPropertyGroup(PropertyGroup):
+    bones: CollectionProperty(type=PsaBonePropertyGroup)
+    sequence_count: IntProperty(default=0)
+
+
+class PsaImportPropertyGroup(PropertyGroup):
+    psa_file_path: StringProperty(default='', options=set(), update=on_psa_file_path_updated, name='PSA File Path')
+    psa_error: StringProperty(default='')
+    psa: PointerProperty(type=PsaDataPropertyGroup)
+    sequence_list: CollectionProperty(type=PsaImportActionListItem)
+    sequence_list_index: IntProperty(name='', default=0)
+    should_clean_keys: BoolProperty(default=True, name='Clean Keyframes',
+                                    description='Exclude unnecessary keyframes from being written to the actions',
+                                    options=set())
+    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=set())
+    should_stash: BoolProperty(default=False, name='Stash',
+                               description='Stash each imported action as a strip on a new non-contributing NLA track',
+                               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='Reuse Existing Actions', 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=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=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=bpy.types.Text)
+
+
+def filter_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[int]:
+    bitflag_filter_item = 1 << 30
+    flt_flags = [bitflag_filter_item] * len(sequences)
+
+    if pg.sequence_filter_name is not None:
+        # Filter name is non-empty.
+        if pg.sequence_use_filter_regex:
+            # Use regular expression. If regex pattern doesn't compile, just ignore it.
+            try:
+                regex = re.compile(pg.sequence_filter_name)
+                for i, sequence in enumerate(sequences):
+                    if not regex.match(sequence.action_name):
+                        flt_flags[i] &= ~bitflag_filter_item
+            except re.error:
+                pass
+        else:
+            # User regular text matching.
+            for i, sequence in enumerate(sequences):
+                if not fnmatch.fnmatch(sequence.action_name, f'*{pg.sequence_filter_name}*'):
+                    flt_flags[i] &= ~bitflag_filter_item
+
+    if pg.sequence_filter_is_selected:
+        for i, sequence in enumerate(sequences):
+            if not sequence.is_selected:
+                flt_flags[i] &= ~bitflag_filter_item
+
+    if pg.sequence_use_filter_invert:
+        # Invert filter flags for all items.
+        for i, sequence in enumerate(sequences):
+            flt_flags[i] ^= bitflag_filter_item
+
+    return flt_flags
+
+
+def get_visible_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[
+    PsaImportActionListItem]:
+    bitflag_filter_item = 1 << 30
+    visible_sequences = []
+    for i, flag in enumerate(filter_sequences(pg, sequences)):
+        if bool(flag & bitflag_filter_item):
+            visible_sequences.append(sequences[i])
+    return visible_sequences
+
+
+class PSA_UL_SequenceList(UIList):
+
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+        row = layout.row(align=True)
+        split = row.split(align=True, factor=0.75)
+        column = split.row(align=True)
+        column.alignment = 'LEFT'
+        column.prop(item, 'is_selected', icon_only=True)
+        column.label(text=item.action_name)
+
+    def draw_filter(self, context, layout):
+        pg = context.scene.psa_import
+        row = layout.row()
+        subrow = row.row(align=True)
+        subrow.prop(pg, 'sequence_filter_name', text="")
+        subrow.prop(pg, 'sequence_use_filter_invert', text="", icon='ARROW_LEFTRIGHT')
+        subrow.prop(pg, 'sequence_use_filter_regex', text="", icon='SORTBYEXT')
+        subrow.prop(pg, 'sequence_filter_is_selected', text="", icon='CHECKBOX_HLT')
+
+    def filter_items(self, context, data, property):
+        pg = context.scene.psa_import
+        sequences = getattr(data, property)
+        flt_flags = filter_sequences(pg, sequences)
+        flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(sequences, 'action_name')
+        return flt_flags, flt_neworder
+
+
+class PSA_UL_ImportSequenceList(PSA_UL_SequenceList, UIList):
+    pass
+
+
+class PSA_UL_ImportActionList(PSA_UL_SequenceList, UIList):
+    pass
+
+
+class PsaImportSequencesFromText(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'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_import
+        return len(pg.sequence_list) > 0
+
+    def invoke(self, context, event):
+        return context.window_manager.invoke_props_dialog(self, width=256)
+
+    def draw(self, context):
+        layout = self.layout
+        pg = context.scene.psa_import
+        layout.label(icon='INFO', text='Each sequence name should be on a new line.')
+        layout.prop(pg, 'select_text', text='')
+
+    def execute(self, context):
+        pg = context.scene.psa_import
+        contents = pg.select_text.as_string()
+        count = 0
+        for line in contents.split('\n'):
+            for sequence in pg.sequence_list:
+                if sequence.action_name == line:
+                    sequence.is_selected = True
+                    count += 1
+        self.report({'INFO'}, f'Selected {count} sequence(s)')
+        return {'FINISHED'}
+
+
+class PsaImportSequencesSelectAll(Operator):
+    bl_idname = 'psa_import.sequences_select_all'
+    bl_label = 'All'
+    bl_description = 'Select all visible sequences'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_import
+        visible_sequences = get_visible_sequences(pg, pg.sequence_list)
+        has_unselected_actions = any(map(lambda action: not action.is_selected, visible_sequences))
+        return len(visible_sequences) > 0 and has_unselected_actions
+
+    def execute(self, context):
+        pg = context.scene.psa_import
+        visible_sequences = get_visible_sequences(pg, pg.sequence_list)
+        for sequence in visible_sequences:
+            sequence.is_selected = True
+        return {'FINISHED'}
+
+
+class PsaImportSequencesDeselectAll(Operator):
+    bl_idname = 'psa_import.sequences_deselect_all'
+    bl_label = 'None'
+    bl_description = 'Deselect all visible sequences'
+    bl_options = {'INTERNAL'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_import
+        visible_sequences = get_visible_sequences(pg, pg.sequence_list)
+        has_selected_sequences = any(map(lambda sequence: sequence.is_selected, visible_sequences))
+        return len(visible_sequences) > 0 and has_selected_sequences
+
+    def execute(self, context):
+        pg = context.scene.psa_import
+        visible_sequences = get_visible_sequences(pg, pg.sequence_list)
+        for sequence in visible_sequences:
+            sequence.is_selected = False
+        return {'FINISHED'}
+
+
+class PSA_PT_ImportPanel_Advanced(Panel):
+    bl_space_type = 'PROPERTIES'
+    bl_region_type = 'WINDOW'
+    bl_label = 'Advanced'
+    bl_options = {'DEFAULT_CLOSED'}
+    bl_parent_id = 'PSA_PT_ImportPanel'
+
+    def draw(self, context):
+        layout = self.layout
+        pg = context.scene.psa_import
+
+        col = layout.column(heading="Options")
+        col.use_property_split = True
+        col.use_property_decorate = False
+        col.prop(pg, 'should_clean_keys')
+        col.separator()
+        col.prop(pg, 'should_use_fake_user')
+        col.prop(pg, 'should_stash')
+        col.prop(pg, 'should_use_action_name_prefix')
+
+        if pg.should_use_action_name_prefix:
+            col.prop(pg, 'action_name_prefix')
+
+
+class PSA_PT_ImportPanel(Panel):
+    bl_space_type = 'PROPERTIES'
+    bl_region_type = 'WINDOW'
+    bl_label = 'PSA Import'
+    bl_context = 'data'
+    bl_category = 'PSA Import'
+    bl_options = {'DEFAULT_CLOSED'}
+
+    @classmethod
+    def poll(cls, context):
+        return context.object.type == 'ARMATURE'
+
+    def draw(self, context):
+        layout = self.layout
+        pg = context.scene.psa_import
+
+        row = layout.row(align=True)
+        row.operator(PsaImportSelectFile.bl_idname, text='', icon='FILEBROWSER')
+        row.prop(pg, 'psa_file_path', text='')
+        row.operator(PsaImportFileReload.bl_idname, text='', icon='FILE_REFRESH')
+
+        if pg.psa_error != '':
+            row = layout.row()
+            row.label(text='File could not be read', icon='ERROR')
+
+        box = layout.box()
+
+        box.label(text=f'Sequences ({len(pg.sequence_list)})', icon='ARMATURE_DATA')
+
+        # select
+        rows = max(3, min(len(pg.sequence_list), 10))
+
+        row = box.row()
+        col = row.column()
+
+        row2 = col.row(align=True)
+        row2.label(text='Select')
+        row2.operator(PsaImportSequencesFromText.bl_idname, text='', icon='TEXT')
+        row2.operator(PsaImportSequencesSelectAll.bl_idname, text='All', icon='CHECKBOX_HLT')
+        row2.operator(PsaImportSequencesDeselectAll.bl_idname, text='None', icon='CHECKBOX_DEHLT')
+
+        col = col.row()
+        col.template_list('PSA_UL_ImportSequenceList', '', pg, 'sequence_list', pg, 'sequence_list_index', rows=rows)
+
+        col = layout.column(heading='')
+        col.use_property_split = True
+        col.use_property_decorate = False
+        col.prop(pg, 'should_overwrite')
+
+        col = layout.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')
+
+        selected_sequence_count = sum(map(lambda x: x.is_selected, pg.sequence_list))
+
+        row = layout.row()
+
+        import_button_text = 'Import'
+        if selected_sequence_count > 0:
+            import_button_text = f'Import ({selected_sequence_count})'
+
+        row.operator(PsaImportOperator.bl_idname, text=import_button_text)
+
+
+class PsaImportFileReload(Operator):
+    bl_idname = 'psa_import.file_reload'
+    bl_label = 'Refresh'
+    bl_options = {'INTERNAL'}
+    bl_description = 'Refresh the PSA file'
+
+    def execute(self, context):
+        load_psa_file(context)
+        return {"FINISHED"}
+
+
+class PsaImportSelectFile(Operator):
+    bl_idname = 'psa_import.select_file'
+    bl_label = 'Select'
+    bl_options = {'INTERNAL'}
+    bl_description = 'Select a PSA file from which to import animations'
+    filepath: bpy.props.StringProperty(subtype='FILE_PATH')
+    filter_glob: bpy.props.StringProperty(default="*.psa", options={'HIDDEN'})
+
+    def execute(self, context):
+        context.scene.psa_import.psa_file_path = self.filepath
+        return {"FINISHED"}
+
+    def invoke(self, context, event):
+        context.window_manager.fileselect_add(self)
+        return {"RUNNING_MODAL"}
+
+
+class PsaImportOperator(Operator):
+    bl_idname = 'psa_import.import'
+    bl_label = 'Import'
+    bl_description = 'Import the selected animations into the scene as actions'
+    bl_options = {'INTERNAL', 'UNDO'}
+
+    @classmethod
+    def poll(cls, context):
+        pg = context.scene.psa_import
+        active_object = context.view_layer.objects.active
+        if active_object is None or active_object.type != 'ARMATURE':
+            return False
+        return any(map(lambda x: x.is_selected, pg.sequence_list))
+
+    def execute(self, context):
+        pg = context.scene.psa_import
+        psa_reader = PsaReader(pg.psa_file_path)
+        sequence_names = [x.action_name for x in pg.sequence_list if x.is_selected]
+
+        options = PsaImportOptions()
+        options.sequence_names = sequence_names
+        options.should_clean_keys = pg.should_clean_keys
+        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 ''
+        options.should_overwrite = pg.should_overwrite
+        options.should_write_metadata = pg.should_write_metadata
+        options.should_write_keyframes = pg.should_write_keyframes
+
+        PsaImporter().import_psa(psa_reader, context.view_layer.objects.active, options)
+
+        self.report({'INFO'}, f'Imported {len(sequence_names)} action(s)')
+
+        return {'FINISHED'}
+
+
+class PsaImportFileSelectOperator(Operator, ImportHelper):
+    bl_idname = 'psa_import.file_select'
+    bl_label = 'File Select'
+    bl_options = {'INTERNAL'}
+    filename_ext = '.psa'
+    filter_glob: StringProperty(default='*.psa', options={'HIDDEN'})
+    filepath: StringProperty(
+        name='File Path',
+        description='File path used for importing the PSA file',
+        maxlen=1024,
+        default='')
+
+    def invoke(self, context, event):
+        context.window_manager.fileselect_add(self)
+        return {'RUNNING_MODAL'}
+
+    def execute(self, context):
+        pg = context.scene.psa_import
+        pg.psa_file_path = self.filepath
+        return {'FINISHED'}
+
+
+classes = (
+    PsaImportActionListItem,
+    PsaBonePropertyGroup,
+    PsaDataPropertyGroup,
+    PsaImportPropertyGroup,
+    PSA_UL_SequenceList,
+    PSA_UL_ImportSequenceList,
+    PSA_UL_ImportActionList,
+    PsaImportSequencesSelectAll,
+    PsaImportSequencesDeselectAll,
+    PsaImportSequencesFromText,
+    PsaImportFileReload,
+    PSA_PT_ImportPanel,
+    PSA_PT_ImportPanel_Advanced,
+    PsaImportOperator,
+    PsaImportFileSelectOperator,
+    PsaImportSelectFile,
+)

io_scene_psk_psa/psa/reader.py

@@ -0,0 +1,93 @@
+import ctypes
+
+import numpy as np
+
+from .data import *
+
+
+class PsaReader(object):
+    """
+    This class reads the sequences and bone information immediately upon instantiation and hold onto a file handle.
+    The key data is not read into memory upon instantiation due to it's potentially very large size.
+    To read the key data for a particular sequence, call `read_sequence_keys`.
+    """
+
+    def __init__(self, path):
+        self.keys_data_offset: int = 0
+        self.fp = open(path, 'rb')
+        self.psa: Psa = self._read(self.fp)
+
+    @property
+    def bones(self):
+        return self.psa.bones
+
+    @property
+    def sequences(self) -> OrderedDict[Psa.Sequence]:
+        return self.psa.sequences
+
+    def read_sequence_data_matrix(self, sequence_name: str):
+        sequence = self.psa.sequences[sequence_name]
+        keys = self.read_sequence_keys(sequence_name)
+        bone_count = len(self.bones)
+        matrix_size = sequence.frame_count, bone_count, 7
+        matrix = np.zeros(matrix_size)
+        keys_iter = iter(keys)
+        for frame_index in range(sequence.frame_count):
+            for bone_index in range(bone_count):
+                matrix[frame_index, bone_index, :] = list(next(keys_iter).data)
+        return matrix
+
+    def read_sequence_keys(self, sequence_name: str) -> List[Psa.Key]:
+        """ Reads and returns the key data for a sequence.
+
+        :param sequence_name: The name of the sequence.
+        :return: A list of Psa.Keys.
+        """
+        # Set the file reader to the beginning of the keys data
+        sequence = self.psa.sequences[sequence_name]
+        data_size = sizeof(Psa.Key)
+        bone_count = len(self.psa.bones)
+        buffer_length = data_size * bone_count * sequence.frame_count
+        sequence_keys_offset = self.keys_data_offset + (sequence.frame_start_index * bone_count * data_size)
+        self.fp.seek(sequence_keys_offset, 0)
+        buffer = self.fp.read(buffer_length)
+        offset = 0
+        keys = []
+        for _ in range(sequence.frame_count * bone_count):
+            key = Psa.Key.from_buffer_copy(buffer, offset)
+            keys.append(key)
+            offset += data_size
+        return keys
+
+    @staticmethod
+    def _read_types(fp, data_class: ctypes.Structure, section: Section, data):
+        buffer_length = section.data_size * section.data_count
+        buffer = fp.read(buffer_length)
+        offset = 0
+        for _ in range(section.data_count):
+            data.append(data_class.from_buffer_copy(buffer, offset))
+            offset += section.data_size
+
+    def _read(self, fp) -> Psa:
+        psa = Psa()
+        while fp.read(1):
+            fp.seek(-1, 1)
+            section = Section.from_buffer_copy(fp.read(ctypes.sizeof(Section)))
+            if section.name == b'ANIMHEAD':
+                pass
+            elif section.name == b'BONENAMES':
+                PsaReader._read_types(fp, Psa.Bone, section, psa.bones)
+            elif section.name == b'ANIMINFO':
+                sequences = []
+                PsaReader._read_types(fp, Psa.Sequence, section, sequences)
+                for sequence in sequences:
+                    psa.sequences[sequence.name.decode()] = sequence
+            elif section.name == b'ANIMKEYS':
+                # Skip keys on this pass. We will keep this file open and read from it as needed.
+                self.keys_data_offset = fp.tell()
+                fp.seek(section.data_size * section.data_count, 1)
+            elif section.name in [b'SCALEKEYS']:
+                fp.seek(section.data_size * section.data_count, 1)
+            else:
+                raise RuntimeError(f'Unrecognized section "{section.name}"')
+        return psa

io_scene_psk_psa/psk/builder.py

@@ -1,15 +1,21 @@
-import bpy
-import bmesh
 from collections import OrderedDict
-from .data import *
 
-# https://github.com/bwrsandman/blender-addons/blob/master/io_export_unreal_psk_psa.py
+from .data import *
+from ..helpers import *
+
 
 class PskInputObjects(object):
     def __init__(self):
         self.mesh_objects = []
         self.armature_object = None
 
+
+class PskBuilderOptions(object):
+    def __init__(self):
+        self.bone_filter_mode = 'ALL'
+        self.bone_group_indices = []
+
+
 class PskBuilder(object):
     def __init__(self):
         pass
@@ -39,7 +45,7 @@ class PskBuilder(object):
             modifiers = [x for x in obj.modifiers if x.type == 'ARMATURE']
             if len(modifiers) == 0:
                 continue
-            elif len(modifiers) == 2:
+            elif len(modifiers) > 1:
                 raise RuntimeError(f'Mesh "{obj.name}" must have only one armature modifier')
             armature_modifier_objects.add(modifiers[0].object)
 
@@ -50,38 +56,40 @@ class PskBuilder(object):
 
         return input_objects
 
-    def build(self, context) -> Psk:
+    def build(self, context, options: PskBuilderOptions) -> Psk:
         input_objects = PskBuilder.get_input_objects(context)
-        wedge_count = sum([len(m.data.loops) for m in input_objects.mesh_objects])
-        if wedge_count <= 65536:
-            wedge_type = Psk.Wedge16
-        else:
-            wedge_type = Psk.Wedge32
+
+        armature_object = input_objects.armature_object
 
         psk = Psk()
-
+        bones = []
         materials = OrderedDict()
 
-        if input_objects.armature_object is None:
-            # Static mesh (no armature)
+        if armature_object is None:
+            # If the mesh has no armature object, 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('static', encoding='utf-8')
+            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(0, 0, 0)
-            psk_bone.rotation = Quaternion(0, 0, 0, 1)
+            psk_bone.location = Vector3.zero()
+            psk_bone.rotation = Quaternion.identity()
             psk.bones.append(psk_bone)
         else:
-            bones = list(input_objects.armature_object.data.bones)
+            bone_names = get_export_bone_names(armature_object, options.bone_filter_mode, options.bone_group_indices)
+            bones = [armature_object.data.bones[bone_name] for bone_name in bone_names]
+
             for bone in bones:
                 psk_bone = Psk.Bone()
-                psk_bone.name = bytes(bone.name, encoding='utf-8')
+                psk_bone.name = bytes(bone.name, encoding='windows-1252')
                 psk_bone.flags = 0
-                psk_bone.children_count = len(bone.children)
+                psk_bone.children_count = 0
 
                 try:
-                    psk_bone.parent_index = bones.index(bone.parent)
+                    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
 
@@ -95,8 +103,8 @@ class PskBuilder(object):
                     parent_tail = quat_parent @ bone.parent.tail
                     location = (parent_tail - parent_head) + bone.head
                 else:
-                    location = input_objects.armature_object.matrix_local @ bone.head
-                    rot_matrix = bone.matrix @ input_objects.armature_object.matrix_local.to_3x3()
+                    location = armature_object.matrix_local @ bone.head
+                    rot_matrix = bone.matrix @ armature_object.matrix_local.to_3x3()
                     rotation = rot_matrix.to_quaternion()
 
                 psk_bone.location.x = location.x
@@ -110,12 +118,9 @@ class PskBuilder(object):
 
                 psk.bones.append(psk_bone)
 
-        vertex_offset = 0
-        wedge_offset = 0
-        weight_offset = 0
-
-        # TODO: if there is an edge-split modifier, we need to apply it (maybe?)
         for object in input_objects.mesh_objects:
+            vertex_offset = len(psk.points)
+
             # VERTICES
             for vertex in object.data.vertices:
                 point = Vector3()
@@ -125,17 +130,7 @@ class PskBuilder(object):
                 point.z = v.z
                 psk.points.append(point)
 
-            # WEDGES
             uv_layer = object.data.uv_layers.active.data
-            psk.wedges.extend([wedge_type() for _ in range(len(object.data.loops))])
-
-            for loop_index, loop in enumerate(object.data.loops):
-                wedge = psk.wedges[wedge_offset + loop_index]
-                wedge.material_index = 0  # NOTE: this material index is set properly while building the faces
-                wedge.point_index = loop.vertex_index + vertex_offset
-                wedge.u, wedge.v = uv_layer[loop_index].uv
-                wedge.v = 1.0 - wedge.v
-                psk.wedges.append(wedge)
 
             # MATERIALS
             material_indices = []
@@ -143,8 +138,10 @@ class PskBuilder(object):
                 if m is None:
                     raise RuntimeError('Material cannot be empty (index ' + str(i) + ')')
                 if m.name in materials:
+                    # Material already evaluated, just get its index.
                     material_index = list(materials.keys()).index(m.name)
                 else:
+                    # New material.
                     material = Psk.Material()
                     material.name = bytes(m.name, encoding='utf-8')
                     material.texture_index = len(psk.materials)
@@ -153,30 +150,76 @@ class PskBuilder(object):
                     material_index = material.texture_index
                 material_indices.append(material_index)
 
-            # FACES
+            # WEDGES
             object.data.calc_loop_triangles()
+
+            # Build a list of non-unique wedges.
+            wedges = []
+            for loop_index, loop in enumerate(object.data.loops):
+                wedge = Psk.Wedge()
+                wedge.point_index = loop.vertex_index + vertex_offset
+                wedge.u, wedge.v = uv_layer[loop_index].uv
+                wedge.v = 1.0 - wedge.v
+                wedges.append(wedge)
+
+            # Assign material indices to the wedges.
+            for triangle in object.data.loop_triangles:
+                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
+            wedge_indices = {}
+            loop_wedge_indices = [-1] * len(object.data.loops)
+            for loop_index, wedge in enumerate(wedges):
+                wedge_hash = hash(wedge)
+                if wedge_hash in wedge_indices:
+                    loop_wedge_indices[loop_index] = wedge_indices[wedge_hash]
+                else:
+                    wedge_index = len(psk.wedges)
+                    wedge_indices[wedge_hash] = wedge_index
+                    psk.wedges.append(wedge)
+                    loop_wedge_indices[loop_index] = wedge_index
+
+            # FACES
             poly_groups, groups = object.data.calc_smooth_groups(use_bitflags=True)
             for f in object.data.loop_triangles:
                 face = Psk.Face()
                 face.material_index = material_indices[f.material_index]
-                face.wedge_index_1 = f.loops[2] + wedge_offset
-                face.wedge_index_2 = f.loops[1] + wedge_offset
-                face.wedge_index_3 = f.loops[0] + wedge_offset
+                face.wedge_indices[0] = loop_wedge_indices[f.loops[2]]
+                face.wedge_indices[1] = loop_wedge_indices[f.loops[1]]
+                face.wedge_indices[2] = loop_wedge_indices[f.loops[0]]
                 face.smoothing_groups = poly_groups[f.polygon_index]
                 psk.faces.append(face)
-                # update the material index of the wedges
-                for i in range(3):
-                    psk.wedges[wedge_offset + f.loops[i]].material_index = face.material_index
 
             # WEIGHTS
-            # TODO: bone ~> vg might not be 1:1, provide a nice error message if this is the case
-            if input_objects.armature_object is not None:
-                armature = input_objects.armature_object.data
-                bone_names = [x.name for x in armature.bones]
+            if armature_object is not None:
+                # 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]
                 vertex_group_names = [x.name for x in object.vertex_groups]
-                bone_indices = [bone_names.index(name) for name in vertex_group_names]
+                vertex_group_bone_indices = 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)
+                    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.
+                        # If there is, we can traverse the ancestors of that bone to find an alternate bone to use for
+                        # weighting the vertices belonging to this vertex group.
+                        if vertex_group_name in armature_object.data.bones:
+                            bone = armature_object.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
+                                    break
+                                except ValueError:
+                                    bone = bone.parent
                 for vertex_group_index, vertex_group in enumerate(object.vertex_groups):
-                    bone_index = bone_indices[vertex_group_index]
+                    if vertex_group_index not in vertex_group_bone_indices:
+                        # Vertex group has no associated bone, skip it.
+                        continue
+                    bone_index = vertex_group_bone_indices[vertex_group_index]
                     for vertex_index in range(len(object.data.vertices)):
                         try:
                             weight = vertex_group.weight(vertex_index)
@@ -190,8 +233,4 @@ class PskBuilder(object):
                         w.weight = weight
                         psk.weights.append(w)
 
-            vertex_offset += len(psk.points)
-            wedge_offset += len(psk.wedges)
-            weight_offset += len(psk.weights)
-
         return psk

io_scene_psk_psa/psk/data.py

@@ -1,35 +1,52 @@
 from typing import List
+
 from ..data import *
 
 
 class Psk(object):
+    class Wedge(object):
+        def __init__(self):
+            self.point_index: int = 0
+            self.u: float = 0.0
+            self.v: float = 0.0
+            self.material_index: int = 0
+
+        def __hash__(self):
+            return hash(f'{self.point_index}-{self.u}-{self.v}-{self.material_index}')
 
     class Wedge16(Structure):
         _fields_ = [
-            ('point_index', c_int16),
+            ('point_index', c_uint16),
             ('padding1', c_int16),
             ('u', c_float),
             ('v', c_float),
-            ('material_index', c_int8),
+            ('material_index', c_uint8),
             ('reserved', c_int8),
             ('padding2', c_int16)
         ]
 
     class Wedge32(Structure):
         _fields_ = [
-            ('point_index', c_int32),
+            ('point_index', c_uint32),
             ('u', c_float),
             ('v', c_float),
-            ('material_index', c_int32)
+            ('material_index', c_uint32)
         ]
 
     class Face(Structure):
         _fields_ = [
-            ('wedge_index_1', c_int16),
-            ('wedge_index_2', c_int16),
-            ('wedge_index_3', c_int16),
-            ('material_index', c_int8),
-            ('aux_material_index', c_int8),
+            ('wedge_indices', c_uint16 * 3),
+            ('material_index', c_uint8),
+            ('aux_material_index', c_uint8),
+            ('smoothing_groups', c_int32)
+        ]
+
+    class Face32(Structure):
+        _pack_ = 1
+        _fields_ = [
+            ('wedge_indices', c_uint32 * 3),
+            ('material_index', c_uint8),
+            ('aux_material_index', c_uint8),
             ('smoothing_groups', c_int32)
         ]
 
@@ -63,10 +80,25 @@ class Psk(object):
             ('bone_index', c_int32),
         ]
 
+    @property
+    def has_extra_uvs(self):
+        return len(self.extra_uvs) > 0
+
+    @property
+    def has_vertex_colors(self):
+        return len(self.vertex_colors) > 0
+
+    @property
+    def has_vertex_normals(self):
+        return len(self.vertex_normals) > 0
+
     def __init__(self):
         self.points: List[Vector3] = []
-        self.wedges: List[Psk.Wedge16] = []
+        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.extra_uvs: List[Vector2] = []
+        self.vertex_colors: List[Color] = []
+        self.vertex_normals: List[Vector3] = []

io_scene_psk_psa/psk/exporter.py

@@ -0,0 +1,160 @@
+from typing import Type
+
+from bpy.props import StringProperty, CollectionProperty, IntProperty, EnumProperty
+from bpy.types import Operator, PropertyGroup
+from bpy_extras.io_utils import ExportHelper
+
+from .builder import PskBuilder, PskBuilderOptions
+from .data import *
+from ..helpers import populate_bone_group_list
+from ..types import BoneGroupListItem
+
+MAX_WEDGE_COUNT = 65536
+MAX_POINT_COUNT = 4294967296
+MAX_BONE_COUNT = 256
+MAX_MATERIAL_COUNT = 256
+
+
+class PskExporter(object):
+
+    def __init__(self, psk: Psk):
+        self.psk: Psk = psk
+
+    @staticmethod
+    def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
+        section = Section()
+        section.name = name
+        if data_type is not None and data is not None:
+            section.data_size = sizeof(data_type)
+            section.data_count = len(data)
+        fp.write(section)
+        if data is not None:
+            for datum in data:
+                fp.write(datum)
+
+    def export(self, path: str):
+        if len(self.psk.wedges) > MAX_WEDGE_COUNT:
+            raise RuntimeError(f'Number of wedges ({len(self.psk.wedges)}) exceeds limit of {MAX_WEDGE_COUNT}')
+        if len(self.psk.bones) > MAX_BONE_COUNT:
+            raise RuntimeError(f'Number of bones ({len(self.psk.bones)}) exceeds limit of {MAX_BONE_COUNT}')
+        if len(self.psk.points) > MAX_POINT_COUNT:
+            raise RuntimeError(f'Numbers of vertices ({len(self.psk.points)}) exceeds limit of {MAX_POINT_COUNT}')
+        if len(self.psk.materials) > MAX_MATERIAL_COUNT:
+            raise RuntimeError(f'Number of materials ({len(self.psk.materials)}) exceeds limit of {MAX_MATERIAL_COUNT}')
+
+        with open(path, 'wb') as fp:
+            self.write_section(fp, b'ACTRHEAD')
+            self.write_section(fp, b'PNTS0000', Vector3, self.psk.points)
+
+            wedges = []
+            for index, w in enumerate(self.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)
+
+            self.write_section(fp, b'VTXW0000', Psk.Wedge16, wedges)
+            self.write_section(fp, b'FACE0000', Psk.Face, self.psk.faces)
+            self.write_section(fp, b'MATT0000', Psk.Material, self.psk.materials)
+            self.write_section(fp, b'REFSKELT', Psk.Bone, self.psk.bones)
+            self.write_section(fp, b'RAWWEIGHTS', Psk.Weight, self.psk.weights)
+
+
+def is_bone_filter_mode_item_available(context, identifier):
+    input_objects = PskBuilder.get_input_objects(context)
+    armature_object = input_objects.armature_object
+    if identifier == 'BONE_GROUPS':
+        if not armature_object or not armature_object.pose or not armature_object.pose.bone_groups:
+            return False
+    # else if... you can set up other conditions if you add more options
+    return True
+
+
+class PskExportOperator(Operator, ExportHelper):
+    bl_idname = 'export.psk'
+    bl_label = 'Export'
+    bl_options = {'INTERNAL', 'UNDO'}
+    __doc__ = 'Export mesh and armature to PSK'
+    filename_ext = '.psk'
+    filter_glob: StringProperty(default='*.psk', options={'HIDDEN'})
+
+    filepath: StringProperty(
+        name='File Path',
+        description='File path used for exporting the PSK file',
+        maxlen=1024,
+        default='')
+
+    def invoke(self, context, event):
+        try:
+            input_objects = PskBuilder.get_input_objects(context)
+        except RuntimeError as e:
+            self.report({'ERROR_INVALID_CONTEXT'}, str(e))
+            return {'CANCELLED'}
+
+        pg = context.scene.psk_export
+
+        # Populate bone groups list.
+        populate_bone_group_list(input_objects.armature_object, pg.bone_group_list)
+
+        context.window_manager.fileselect_add(self)
+
+        return {'RUNNING_MODAL'}
+
+    def draw(self, context):
+        layout = self.layout
+        scene = context.scene
+        pg = scene.psk_export
+
+        # BONES
+        box = layout.box()
+        box.label(text='Bones', icon='BONE_DATA')
+        bone_filter_mode_items = pg.bl_rna.properties['bone_filter_mode'].enum_items_static
+        row = box.row(align=True)
+        for item in bone_filter_mode_items:
+            identifier = item.identifier
+            item_layout = row.row(align=True)
+            item_layout.prop_enum(pg, 'bone_filter_mode', item.identifier)
+            item_layout.enabled = is_bone_filter_mode_item_available(context, identifier)
+
+        if pg.bone_filter_mode == 'BONE_GROUPS':
+            row = box.row()
+            rows = max(3, min(len(pg.bone_group_list), 10))
+            row.template_list('PSX_UL_BoneGroupList', '', pg, 'bone_group_list', pg, 'bone_group_list_index', rows=rows)
+
+    def execute(self, context):
+        pg = context.scene.psk_export
+        builder = PskBuilder()
+        options = PskBuilderOptions()
+        options.bone_filter_mode = pg.bone_filter_mode
+        options.bone_group_indices = [x.index for x in pg.bone_group_list if x.is_selected]
+        try:
+            psk = builder.build(context, options)
+            exporter = PskExporter(psk)
+            exporter.export(self.filepath)
+        except RuntimeError as e:
+            self.report({'ERROR_INVALID_CONTEXT'}, str(e))
+            return {'CANCELLED'}
+        return {'FINISHED'}
+
+
+class PskExportPropertyGroup(PropertyGroup):
+    bone_filter_mode: EnumProperty(
+        name='Bone Filter',
+        options=set(),
+        description='',
+        items=(
+            ('ALL', 'All', 'All bones will be exported.'),
+            ('BONE_GROUPS', 'Bone Groups',
+             'Only bones belonging to the selected bone groups and their ancestors will be exported.')
+        )
+    )
+    bone_group_list: CollectionProperty(type=BoneGroupListItem)
+    bone_group_list_index: IntProperty(default=0)
+
+
+classes = (
+    PskExportOperator,
+    PskExportPropertyGroup
+)

io_scene_psk_psa/psk/importer.py

@@ -0,0 +1,317 @@
+import os
+import sys
+from math import inf
+from typing import Optional
+
+import bmesh
+import bpy
+import numpy as np
+from bpy.props import BoolProperty, EnumProperty, FloatProperty, StringProperty
+from bpy.types import Operator, PropertyGroup
+from bpy_extras.io_utils import ImportHelper
+from mathutils import Quaternion, Vector, Matrix
+
+from .data import Psk
+from .reader import PskReader
+from ..helpers import rgb_to_srgb
+
+
+class PskImportOptions(object):
+    def __init__(self):
+        self.name = ''
+        self.should_import_vertex_colors = True
+        self.vertex_color_space = 'sRGB'
+        self.should_import_vertex_normals = True
+        self.should_import_extra_uvs = True
+        self.bone_length = 1.0
+
+
+class PskImporter(object):
+    def __init__(self):
+        pass
+
+    def import_psk(self, psk: Psk, context, options: PskImportOptions):
+        # ARMATURE
+        armature_data = bpy.data.armatures.new(options.name)
+        armature_object = bpy.data.objects.new(options.name, armature_data)
+        armature_object.show_in_front = True
+
+        context.scene.collection.objects.link(armature_object)
+
+        try:
+            bpy.ops.object.mode_set(mode='OBJECT')
+        except:
+            pass
+
+        armature_object.select_set(state=True)
+        bpy.context.view_layer.objects.active = armature_object
+
+        bpy.ops.object.mode_set(mode='EDIT')
+
+        # Intermediate bone type for the purpose of construction.
+        class ImportBone(object):
+            def __init__(self, index: int, psk_bone: Psk.Bone):
+                self.index: int = index
+                self.psk_bone: Psk.Bone = psk_bone
+                self.parent: Optional[ImportBone] = None
+                self.local_rotation: Quaternion = Quaternion()
+                self.local_translation: Vector = Vector()
+                self.world_rotation_matrix: Matrix = Matrix()
+                self.world_matrix: Matrix = Matrix()
+                self.vertex_group = None
+                self.orig_quat: Quaternion = Quaternion()
+                self.orig_loc: Vector = Vector()
+                self.post_quat: Quaternion = Quaternion()
+
+        import_bones = []
+
+        for bone_index, psk_bone in enumerate(psk.bones):
+            import_bone = ImportBone(bone_index, psk_bone)
+            psk_bone.parent_index = max(0, psk_bone.parent_index)
+            import_bone.local_rotation = Quaternion(tuple(psk_bone.rotation))
+            import_bone.local_translation = Vector(tuple(psk_bone.location))
+            if psk_bone.parent_index == 0 and bone_index == 0:
+                import_bone.world_rotation_matrix = import_bone.local_rotation.to_matrix()
+                import_bone.world_matrix = Matrix.Translation(import_bone.local_translation)
+            import_bones.append(import_bone)
+
+        for bone_index, bone in enumerate(import_bones):
+            if bone.psk_bone.parent_index == 0 and bone_index == 0:
+                continue
+            parent = import_bones[bone.psk_bone.parent_index]
+            bone.parent = parent
+            bone.world_matrix = parent.world_rotation_matrix.to_4x4()
+            translation = bone.local_translation.copy()
+            translation.rotate(parent.world_rotation_matrix)
+            bone.world_matrix.translation = parent.world_matrix.translation + translation
+            bone.world_rotation_matrix = bone.local_rotation.conjugated().to_matrix()
+            bone.world_rotation_matrix.rotate(parent.world_rotation_matrix)
+
+        for import_bone in import_bones:
+            bone_name = import_bone.psk_bone.name.decode('utf-8')
+            edit_bone = armature_data.edit_bones.new(bone_name)
+
+            if import_bone.parent is not None:
+                edit_bone.parent = armature_data.edit_bones[import_bone.psk_bone.parent_index]
+            else:
+                import_bone.local_rotation.conjugate()
+
+            edit_bone.tail = Vector((0.0, options.bone_length, 0.0))
+            edit_bone_matrix = import_bone.local_rotation.conjugated()
+            edit_bone_matrix.rotate(import_bone.world_matrix)
+            edit_bone_matrix = edit_bone_matrix.to_matrix().to_4x4()
+            edit_bone_matrix.translation = import_bone.world_matrix.translation
+            edit_bone.matrix = edit_bone_matrix
+
+            # Store bind pose information in the bone's custom properties.
+            # This information is used when importing animations from PSA files.
+            edit_bone['orig_quat'] = import_bone.local_rotation
+            edit_bone['orig_loc'] = import_bone.local_translation
+            edit_bone['post_quat'] = import_bone.local_rotation.conjugated()
+
+        # MESH
+        mesh_data = bpy.data.meshes.new(options.name)
+        mesh_object = bpy.data.objects.new(options.name, mesh_data)
+
+        # MATERIALS
+        for material in psk.materials:
+            # TODO: re-use of materials should be an option
+            bpy_material = bpy.data.materials.new(material.name.decode('utf-8'))
+            mesh_data.materials.append(bpy_material)
+
+        bm = bmesh.new()
+
+        # VERTICES
+        for point in psk.points:
+            bm.verts.new(tuple(point))
+
+        bm.verts.ensure_lookup_table()
+
+        degenerate_face_indices = set()
+        for face_index, face in enumerate(psk.faces):
+            point_indices = [bm.verts[psk.wedges[i].point_index] for i in reversed(face.wedge_indices)]
+            try:
+                bm_face = bm.faces.new(point_indices)
+                bm_face.material_index = face.material_index
+            except ValueError:
+                degenerate_face_indices.add(face_index)
+
+        if len(degenerate_face_indices) > 0:
+            print(f'WARNING: Discarded {len(degenerate_face_indices)} degenerate face(s).')
+
+        bm.to_mesh(mesh_data)
+
+        # TEXTURE COORDINATES
+        data_index = 0
+        uv_layer = mesh_data.uv_layers.new(name='VTXW0000')
+        for face_index, face in enumerate(psk.faces):
+            if face_index in degenerate_face_indices:
+                continue
+            face_wedges = [psk.wedges[i] for i in reversed(face.wedge_indices)]
+            for wedge in face_wedges:
+                uv_layer.data[data_index].uv = wedge.u, 1.0 - wedge.v
+                data_index += 1
+
+        # 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
+            for extra_uv_index in range(extra_uv_channel_count):
+                data_index = 0
+                uv_layer = mesh_data.uv_layers.new(name=f'EXTRAUV{extra_uv_index}')
+                for face_index, face in enumerate(psk.faces):
+                    if face_index in degenerate_face_indices:
+                        continue
+                    for wedge_index in reversed(face.wedge_indices):
+                        u, v = psk.extra_uvs[wedge_index_offset + wedge_index]
+                        uv_layer.data[data_index].uv = u, 1.0 - v
+                        data_index += 1
+                wedge_index_offset += len(psk.wedges)
+
+        # VERTEX COLORS
+        if psk.has_vertex_colors and options.should_import_vertex_colors:
+            size = (len(psk.points), 4)
+            vertex_colors = np.full(size, inf)
+            vertex_color_data = mesh_data.vertex_colors.new(name='VERTEXCOLOR')
+            ambiguous_vertex_color_point_indices = []
+
+            for wedge_index, wedge in enumerate(psk.wedges):
+                point_index = wedge.point_index
+                psk_vertex_color = psk.vertex_colors[wedge_index].normalized()
+                if vertex_colors[point_index, 0] != inf and tuple(vertex_colors[point_index]) != psk_vertex_color:
+                    ambiguous_vertex_color_point_indices.append(point_index)
+                else:
+                    vertex_colors[point_index] = psk_vertex_color
+
+            if options.vertex_color_space == 'SRGBA':
+                for i in range(vertex_colors.shape[0]):
+                    vertex_colors[i, :3] = tuple(map(lambda x: rgb_to_srgb(x), vertex_colors[i, :3]))
+
+            for loop_index, loop in enumerate(mesh_data.loops):
+                vertex_color = vertex_colors[loop.vertex_index]
+                if vertex_color is not None:
+                    vertex_color_data.data[loop_index].color = vertex_color
+                else:
+                    vertex_color_data.data[loop_index].color = 1.0, 1.0, 1.0, 1.0
+
+            if len(ambiguous_vertex_color_point_indices) > 0:
+                print(f'WARNING: {len(ambiguous_vertex_color_point_indices)} vertex(es) with ambiguous vertex colors.')
+
+        # 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 = []
+            for vertex_normal in psk.vertex_normals:
+                normals.append(tuple(vertex_normal))
+            mesh_data.normals_split_custom_set_from_vertices(normals)
+            mesh_data.use_auto_smooth = True
+
+        bm.normal_update()
+        bm.free()
+
+        # 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))
+        for import_bone in map(lambda x: import_bones[x], sorted(list(vertex_group_bone_indices))):
+            import_bone.vertex_group = mesh_object.vertex_groups.new(
+                name=import_bone.psk_bone.name.decode('windows-1252'))
+
+        for weight in psk.weights:
+            import_bones[weight.bone_index].vertex_group.add((weight.point_index,), weight.weight, 'ADD')
+
+        # Add armature modifier to our mesh object.
+        armature_modifier = mesh_object.modifiers.new(name='Armature', type='ARMATURE')
+        armature_modifier.object = armature_object
+        mesh_object.parent = armature_object
+
+        context.scene.collection.objects.link(mesh_object)
+
+        try:
+            bpy.ops.object.mode_set(mode='OBJECT')
+        except:
+            pass
+
+
+class PskImportPropertyGroup(PropertyGroup):
+    should_import_vertex_colors: BoolProperty(
+        default=True,
+        options=set(),
+        name='Vertex Colors',
+        description='Import vertex colors from PSKX files, 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='Vertex Normals',
+        options=set(),
+        description='Import vertex normals from PSKX files, if available'
+    )
+    should_import_extra_uvs: BoolProperty(
+        default=True,
+        name='Extra UVs',
+        options=set(),
+        description='Import extra UV maps from PSKX files, if available'
+    )
+    bone_length: FloatProperty(
+        default=1.0,
+        min=sys.float_info.epsilon,
+        step=100,
+        soft_min=1.0,
+        name='Bone Length',
+        options=set(),
+        description='Length of the bones'
+    )
+
+
+class PskImportOperator(Operator, ImportHelper):
+    bl_idname = 'import.psk'
+    bl_label = 'Export'
+    bl_options = {'INTERNAL', 'UNDO'}
+    __doc__ = 'Load a PSK file'
+    filename_ext = '.psk'
+    filter_glob: StringProperty(default='*.psk;*.pskx', options={'HIDDEN'})
+    filepath: StringProperty(
+        name='File Path',
+        description='File path used for exporting the PSK file',
+        maxlen=1024,
+        default='')
+
+    def execute(self, context):
+        pg = context.scene.psk_import
+        reader = PskReader()
+        psk = reader.read(self.filepath)
+        options = PskImportOptions()
+        options.name = os.path.splitext(os.path.basename(self.filepath))[0]
+        options.should_import_extra_uvs = pg.should_import_extra_uvs
+        options.should_import_vertex_colors = pg.should_import_vertex_colors
+        options.should_import_vertex_normals = pg.should_import_vertex_normals
+        options.vertex_color_space = pg.vertex_color_space
+        options.bone_length = pg.bone_length
+        PskImporter().import_psk(psk, context, options)
+        return {'FINISHED'}
+
+    def draw(self, context):
+        pg = context.scene.psk_import
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+        layout.prop(pg, 'should_import_vertex_normals')
+        layout.prop(pg, 'should_import_extra_uvs')
+        layout.prop(pg, 'should_import_vertex_colors')
+        if pg.should_import_vertex_colors:
+            layout.prop(pg, 'vertex_color_space')
+        layout.prop(pg, 'bone_length')
+
+
+classes = (
+    PskImportOperator,
+    PskImportPropertyGroup,
+)

io_scene_psk_psa/psk/reader.py

@@ -0,0 +1,55 @@
+import ctypes
+
+from .data import *
+
+
+class PskReader(object):
+
+    def __init__(self):
+        pass
+
+    @staticmethod
+    def read_types(fp, data_class: ctypes.Structure, section: Section, data):
+        buffer_length = section.data_size * section.data_count
+        buffer = fp.read(buffer_length)
+        offset = 0
+        for _ in range(section.data_count):
+            data.append(data_class.from_buffer_copy(buffer, offset))
+            offset += section.data_size
+
+    def read(self, path) -> Psk:
+        psk = Psk()
+        with open(path, 'rb') as fp:
+            while fp.read(1):
+                fp.seek(-1, 1)
+                section = Section.from_buffer_copy(fp.read(ctypes.sizeof(Section)))
+                if section.name == b'ACTRHEAD':
+                    pass
+                elif section.name == b'PNTS0000':
+                    PskReader.read_types(fp, Vector3, section, psk.points)
+                elif section.name == b'VTXW0000':
+                    if section.data_size == ctypes.sizeof(Psk.Wedge16):
+                        PskReader.read_types(fp, Psk.Wedge16, section, psk.wedges)
+                    elif section.data_size == ctypes.sizeof(Psk.Wedge32):
+                        PskReader.read_types(fp, Psk.Wedge32, section, psk.wedges)
+                    else:
+                        raise RuntimeError('Unrecognized wedge format')
+                elif section.name == b'FACE0000':
+                    PskReader.read_types(fp, Psk.Face, section, psk.faces)
+                elif section.name == b'MATT0000':
+                    PskReader.read_types(fp, Psk.Material, section, psk.materials)
+                elif section.name == b'REFSKELT':
+                    PskReader.read_types(fp, Psk.Bone, section, psk.bones)
+                elif section.name == b'RAWWEIGHTS':
+                    PskReader.read_types(fp, Psk.Weight, section, psk.weights)
+                elif section.name == b'FACE3200':
+                    PskReader.read_types(fp, Psk.Face32, section, psk.faces)
+                elif section.name == b'VERTEXCOLOR':
+                    PskReader.read_types(fp, Color, section, psk.vertex_colors)
+                elif section.name.startswith(b'EXTRAUVS'):
+                    PskReader.read_types(fp, Vector2, section, psk.extra_uvs)
+                elif section.name == b'VTXNORMS':
+                    PskReader.read_types(fp, Vector3, section, psk.vertex_normals)
+                else:
+                    raise RuntimeError(f'Unrecognized section "{section.name} at position {15:fp.tell()}"')
+        return psk

io_scene_psk_psa/types.py

@@ -0,0 +1,26 @@
+from bpy.props import StringProperty, IntProperty, BoolProperty
+from bpy.types import PropertyGroup, UIList
+
+
+class PSX_UL_BoneGroupList(UIList):
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+        row = layout.row()
+        row.prop(item, 'is_selected', text=item.name)
+        row.label(text=str(item.count), icon='BONE_DATA')
+
+
+class BoneGroupListItem(PropertyGroup):
+    name: StringProperty()
+    index: IntProperty()
+    count: IntProperty()
+    is_selected: BoolProperty(default=False)
+
+    @property
+    def name(self):
+        return self.name
+
+
+classes = (
+    BoneGroupListItem,
+    PSX_UL_BoneGroupList,
+)