From e9ba117fa975fcbe449aefe6b19f6ceb5c28c9b5 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 20 Jan 2024 14:48:18 -0800
Subject: [PATCH 01/31] Added file handler for PSK/PSKX files

---
 io_scene_psk_psa/psk/import_/operators.py | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index 1cabb22..75141d7 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -2,7 +2,7 @@ import os
 import sys
 
 from bpy.props import StringProperty, BoolProperty, EnumProperty, FloatProperty
-from bpy.types import Operator
+from bpy.types import Operator, FileHandler, Context
 from bpy_extras.io_utils import ImportHelper
 
 from ..importer import PskImportOptions, import_psk
@@ -11,6 +11,17 @@ from ..reader import read_psk
 empty_set = set()
 
 
+class PSX_FH_psk(FileHandler):
+    bl_idname = 'PSX_FH_psk'
+    bl_label = 'Unreal PSK/PSKX'
+    bl_import_operator = 'import_scene.psk'
+    bl_file_extensions = '.psk;.pskx'
+
+    @classmethod
+    def poll_drop(cls, context: Context):
+        return context.area.type == 'VIEW_3D'
+
+
 class PSK_OT_import(Operator, ImportHelper):
     bl_idname = 'import_scene.psk'
     bl_label = 'Import'
@@ -141,4 +152,5 @@ class PSK_OT_import(Operator, ImportHelper):
 
 classes = (
     PSK_OT_import,
+    PSX_FH_psk,
 )

From 7e6911c709a044bccdcd147995c3d49a2a7b78a5 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 11:26:09 -0800
Subject: [PATCH 02/31] PSK files imported with custom normals will now have
 `Auto Smooth` enabled by default (#67)

---
 io_scene_psk_psa/psk/importer.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index c701db9..f07fd11 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -227,6 +227,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             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
         else:
             mesh_data.shade_smooth()
 

From fda976d0839321013c6f669bd46c39fdb16ed93f Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 11:32:06 -0800
Subject: [PATCH 03/31] Incremented version to 6.1.2

---
 io_scene_psk_psa/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index aa72ddc..f4496db 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -3,7 +3,7 @@ from bpy.app.handlers import persistent
 bl_info = {
     "name": "PSK/PSA Importer/Exporter",
     "author": "Colin Basnett, Yurii Ti",
-    "version": (6, 1, 1),
+    "version": (6, 1, 2),
     "blender": (4, 0, 0),
     "description": "PSK/PSA Import/Export (.psk/.psa)",
     "warning": "",

From 3d3bbb9296b60550081c376765419379b4ca1e85 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 14:50:06 -0800
Subject: [PATCH 04/31] Set the subtype of the bone length property on PSK
 import to distance

---
 io_scene_psk_psa/psk/import_/operators.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index e90b44c..3ebc084 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -82,6 +82,7 @@ class PSK_OT_import(Operator, ImportHelper):
         soft_min=1.0,
         name='Bone Length',
         options=empty_set,
+        subtype='DISTANCE',
         description='Length of the bones'
     )
     should_import_shape_keys: BoolProperty(

From b2f59856817d86d2346c5f6c7fa034f3d3821774 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 14:56:51 -0800
Subject: [PATCH 05/31] Improved PSK vertex color importing to be per-corner
 instead of per-vertex

Previously, the importer was storing the vertex colors in the point
domain. However, the PSK itself stores colors per "wedge", which maps
to corners, resulting in the "ambiguous vertex colors" warning if two
corners mapped to the same vertex but had different colors.

The new method is now more correct and doesn't discard data.
---
 io_scene_psk_psa/psk/importer.py | 49 ++++++++++++++------------------
 1 file changed, 22 insertions(+), 27 deletions(-)

diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index f07fd11..15c0801 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -1,4 +1,3 @@
-from math import inf
 from typing import Optional, List
 
 import bmesh
@@ -17,7 +16,7 @@ class PskImportOptions:
         self.should_import_mesh = True
         self.should_reuse_materials = True
         self.should_import_vertex_colors = True
-        self.vertex_color_space = 'sRGB'
+        self.vertex_color_space = 'SRGB'
         self.should_import_vertex_normals = True
         self.should_import_extra_uvs = True
         self.should_import_skeleton = True
@@ -144,6 +143,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
 
         bm.verts.ensure_lookup_table()
 
+        # FACES
         invalid_face_indices = set()
         for face_index, face in enumerate(psk.faces):
             point_indices = map(lambda i: psk.wedges[i].point_index, reversed(face.wedge_indices))
@@ -192,33 +192,28 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
 
         # 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 = []
+            # Convert vertex colors to sRGB if necessary.
+            psk_vertex_colors = np.zeros((len(psk.vertex_colors), 4))
+            for i in range(len(psk.vertex_colors)):
+                psk_vertex_colors[i,:] = psk.vertex_colors[i].normalized()
+            match options.vertex_color_space:
+                case 'SRGBA':
+                    for i in range(psk_vertex_colors.shape[0]):
+                        psk_vertex_colors[i, :3] = tuple(map(lambda x: rgb_to_srgb(x), psk_vertex_colors[i, :3]))
+                case _:
+                    pass
 
-            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
+            # Map the PSK vertex colors to the face corners.
+            face_corner_colors = np.full((len(psk.faces * 3), 4), 1.0)
+            face_corner_color_index = 0
+            for face_index, face in enumerate(psk.faces):
+                for wedge_index in reversed(face.wedge_indices):
+                    face_corner_colors[face_corner_color_index] = psk_vertex_colors[wedge_index]
+                    face_corner_color_index += 1
 
-            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:
-                result.warnings.append(
-                    f'{len(ambiguous_vertex_color_point_indices)} vertex(es) with ambiguous vertex colors.')
+            # Create the vertex color attribute.
+            face_corner_color_attribute = mesh_data.attributes.new(name='VERTEXCOLOR', type='FLOAT_COLOR', domain='CORNER')
+            face_corner_color_attribute.data.foreach_set('color', face_corner_colors.flatten())
 
         # VERTEX NORMALS
         if psk.has_vertex_normals and options.should_import_vertex_normals:

From 564f7ec221766b9659df85308f9331e2df5b8efc Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 15:23:01 -0800
Subject: [PATCH 06/31] All string literals now use single-quotes instead of
 double-quotes where possible

---
 io_scene_psk_psa/__init__.py              | 18 +++++++-------
 io_scene_psk_psa/helpers.py               |  8 +++----
 io_scene_psk_psa/psa/config.py            |  4 ++--
 io_scene_psk_psa/psa/data.py              |  4 ++--
 io_scene_psk_psa/psa/export/ui.py         |  6 ++---
 io_scene_psk_psa/psa/import_/operators.py |  6 ++---
 io_scene_psk_psa/psa/import_/ui.py        |  8 +++----
 io_scene_psk_psa/psa/importer.py          |  4 ++--
 io_scene_psk_psa/psa/reader.py            | 29 +++++++++++------------
 io_scene_psk_psa/psk/export/operators.py  |  4 ++--
 io_scene_psk_psa/psk/importer.py          |  4 ++--
 io_scene_psk_psa/psk/reader.py            |  2 +-
 12 files changed, 48 insertions(+), 49 deletions(-)

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index f4496db..7570fe9 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -1,15 +1,15 @@
 from bpy.app.handlers import persistent
 
 bl_info = {
-    "name": "PSK/PSA Importer/Exporter",
-    "author": "Colin Basnett, Yurii Ti",
-    "version": (6, 1, 2),
-    "blender": (4, 0, 0),
-    "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"
+    'name': 'PSK/PSA Importer/Exporter',
+    'author': 'Colin Basnett, Yurii Ti',
+    'version': (6, 1, 2),
+    'blender': (4, 0, 0),
+    '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():
diff --git a/io_scene_psk_psa/helpers.py b/io_scene_psk_psa/helpers.py
index f778e1e..b7a6520 100644
--- a/io_scene_psk_psa/helpers.py
+++ b/io_scene_psk_psa/helpers.py
@@ -30,12 +30,12 @@ def get_nla_strips_in_frame_range(animation_data: AnimData, frame_min: float, fr
 
 
 def populate_bone_collection_list(armature_object: Object, bone_collection_list: bpy.props.CollectionProperty) -> None:
-    """
+    '''
     Updates the bone collections collection.
 
     Bone collection selections are preserved between updates unless none of the groups were previously selected;
     otherwise, all collections are selected by default.
-    """
+    '''
     has_selected_collections = any([g.is_selected for g in bone_collection_list])
     unassigned_collection_is_selected, selected_assigned_collection_names = True, []
 
@@ -84,7 +84,7 @@ def check_bone_names(bone_names: Iterable[str]):
 
 
 def get_export_bone_names(armature_object: Object, bone_filter_mode: str, bone_collection_indices: List[int]) -> List[str]:
-    """
+    '''
     Returns a sorted list of bone indices that should be exported for the given bone filter mode and bone collections.
 
     Note that the ancestors of bones within the bone collections will also be present in the returned list.
@@ -93,7 +93,7 @@ def get_export_bone_names(armature_object: Object, bone_filter_mode: str, bone_c
     :param bone_filter_mode: One of ['ALL', 'BONE_COLLECTIONS']
     :param bone_collection_indices: List of bone collection 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')
 
diff --git a/io_scene_psk_psa/psa/config.py b/io_scene_psk_psa/psa/config.py
index 184d59c..3016c59 100644
--- a/io_scene_psk_psa/psa/config.py
+++ b/io_scene_psk_psa/psa/config.py
@@ -14,7 +14,7 @@ class PsaConfig:
 
 
 def _load_config_file(file_path: str) -> ConfigParser:
-    """
+    '''
     UEViewer exports a dialect of INI files that is not compatible with Python's ConfigParser.
     Specifically, it allows values in this format:
 
@@ -24,7 +24,7 @@ def _load_config_file(file_path: str) -> ConfigParser:
 
     This is not allowed in Python's ConfigParser, which requires a '=' character after each key name.
     To work around this, we'll modify the file to add the '=' character after each key name if it is missing.
-    """
+    '''
     with open(file_path, 'r') as f:
         lines = f.read().split('\n')
 
diff --git a/io_scene_psk_psa/psa/data.py b/io_scene_psk_psa/psa/data.py
index 8d5d8e5..776d244 100644
--- a/io_scene_psk_psa/psa/data.py
+++ b/io_scene_psk_psa/psa/data.py
@@ -4,10 +4,10 @@ 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 the keys for a sequence.
-"""
+'''
 
 
 class Psa:
diff --git a/io_scene_psk_psa/psa/export/ui.py b/io_scene_psk_psa/psa/export/ui.py
index d302265..203b530 100644
--- a/io_scene_psk_psa/psa/export/ui.py
+++ b/io_scene_psk_psa/psa/export/ui.py
@@ -30,15 +30,15 @@ class PSA_UL_export_sequences(UIList):
         pg = getattr(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.prop(pg, 'sequence_filter_name', text='')
+        subrow.prop(pg, 'sequence_use_filter_invert', text='', icon='ARROW_LEFTRIGHT')
         # subrow.prop(pg, 'sequence_use_filter_sort_reverse', text='', icon='SORT_ASC')
 
         if pg.sequence_source == 'ACTIONS':
             subrow = row.row(align=True)
             subrow.prop(pg, 'sequence_filter_asset', icon_only=True, icon='ASSET_MANAGER')
             subrow.prop(pg, 'sequence_filter_pose_marker', icon_only=True, icon='PMARKER')
-            subrow.prop(pg, 'sequence_filter_reversed', text="", icon='FRAME_PREV')
+            subrow.prop(pg, 'sequence_filter_reversed', text='', icon='FRAME_PREV')
 
     def filter_items(self, context, data, prop):
         pg = getattr(context.scene, 'psa_export')
diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index 4b75a1a..7891a32 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -95,15 +95,15 @@ class PSA_OT_import_select_file(Operator):
     bl_options = {'INTERNAL'}
     bl_description = 'Select a PSA file from which to import animations'
     filepath: StringProperty(subtype='FILE_PATH')
-    filter_glob: StringProperty(default="*.psa", options={'HIDDEN'})
+    filter_glob: StringProperty(default='*.psa', options={'HIDDEN'})
 
     def execute(self, context):
         getattr(context.scene, 'psa_import').psa_file_path = self.filepath
-        return {"FINISHED"}
+        return {'FINISHED'}
 
     def invoke(self, context, event):
         context.window_manager.fileselect_add(self)
-        return {"RUNNING_MODAL"}
+        return {'RUNNING_MODAL'}
 
 
 def load_psa_file(context, filepath: str):
diff --git a/io_scene_psk_psa/psa/import_/ui.py b/io_scene_psk_psa/psa/import_/ui.py
index 597c134..987a8c1 100644
--- a/io_scene_psk_psa/psa/import_/ui.py
+++ b/io_scene_psk_psa/psa/import_/ui.py
@@ -17,10 +17,10 @@ class PSA_UL_sequences(UIList):
         pg = getattr(context.scene, 'psa_import')
         row = layout.row()
         sub_row = row.row(align=True)
-        sub_row.prop(pg, 'sequence_filter_name', text="")
-        sub_row.prop(pg, 'sequence_use_filter_invert', text="", icon='ARROW_LEFTRIGHT')
-        sub_row.prop(pg, 'sequence_use_filter_regex', text="", icon='SORTBYEXT')
-        sub_row.prop(pg, 'sequence_filter_is_selected', text="", icon='CHECKBOX_HLT')
+        sub_row.prop(pg, 'sequence_filter_name', text='')
+        sub_row.prop(pg, 'sequence_use_filter_invert', text='', icon='ARROW_LEFTRIGHT')
+        sub_row.prop(pg, 'sequence_use_filter_regex', text='', icon='SORTBYEXT')
+        sub_row.prop(pg, 'sequence_filter_is_selected', text='', icon='CHECKBOX_HLT')
 
     def filter_items(self, context, data, property_):
         pg = getattr(context.scene, 'psa_import')
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 5864645..44f2572 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -64,12 +64,12 @@ class PsaImportResult:
 
 
 def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_names: List[str], bone_mapping_mode: str = 'EXACT') -> Optional[int]:
-    """
+    '''
     @param psa_bone_name: The name of the PSA bone.
     @param armature_bone_names: The names of the bones in the armature.
     @param bone_mapping_mode: One of 'EXACT' or 'CASE_INSENSITIVE'.
     @return: The index of the armature bone that corresponds to the given PSA bone, or None if no such bone exists.
-    """
+    '''
     for armature_bone_index, armature_bone_name in enumerate(armature_bone_names):
         if bone_mapping_mode == 'CASE_INSENSITIVE':
             if armature_bone_name.lower() == psa_bone_name.lower():
diff --git a/io_scene_psk_psa/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index 6b74c2f..e60fbb4 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -11,24 +11,23 @@ def _try_fix_cue4parse_issue_103(sequences) -> bool:
     # The issue was that the frame_start_index was not being set correctly, and was always being set to the same value
     # as the frame_count.
     # This fix will eventually be deprecated as it is only necessary for files exported prior to the fix.
-    if len(sequences) > 0:
-        if sequences[0].frame_start_index == sequences[0].frame_count:
-            # Manually set the frame_start_index for each sequence. This assumes that the sequences are in order with
-            # no shared frames between sequences (all exporters that I know of do this, so it's a safe assumption).
-            frame_start_index = 0
-            for i, sequence in enumerate(sequences):
-                sequence.frame_start_index = frame_start_index
-                frame_start_index += sequence.frame_count
-            return True
+    if len(sequences) == 0 and sequences[0].frame_start_index == sequences[0].frame_count:
+        # Manually set the frame_start_index for each sequence. This assumes that the sequences are in order with
+        # no shared frames between sequences (all exporters that I know of do this, so it's a safe assumption).
+        frame_start_index = 0
+        for i, sequence in enumerate(sequences):
+            sequence.frame_start_index = frame_start_index
+            frame_start_index += sequence.frame_count
+        return True
     return False
 
 
 class PsaReader(object):
-    """
+    '''
     This class reads the sequences and bone information immediately upon instantiation and holds onto a file handle.
     The keyframe data is not read into memory upon instantiation due to its 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
@@ -44,11 +43,11 @@ class PsaReader(object):
         return self.psa.sequences
 
     def read_sequence_data_matrix(self, sequence_name: str) -> np.ndarray:
-        """
+        '''
         Reads and returns the data matrix for the given sequence.
         @param sequence_name: The name of the sequence.
         @return: An FxBx7 matrix where F is the number of frames, B is the number of bones.
-        """
+        '''
         sequence = self.psa.sequences[sequence_name]
         keys = self.read_sequence_keys(sequence_name)
         bone_count = len(self.bones)
@@ -61,12 +60,12 @@ class PsaReader(object):
         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)
diff --git a/io_scene_psk_psa/psk/export/operators.py b/io_scene_psk_psa/psk/export/operators.py
index 80e097f..a902b27 100644
--- a/io_scene_psk_psa/psk/export/operators.py
+++ b/io_scene_psk_psa/psk/export/operators.py
@@ -51,7 +51,7 @@ class PSK_OT_material_list_move_up(Operator):
         pg = getattr(context.scene, 'psk_export')
         pg.material_list.move(pg.material_list_index, pg.material_list_index - 1)
         pg.material_list_index -= 1
-        return {"FINISHED"}
+        return {'FINISHED'}
 
 
 class PSK_OT_material_list_move_down(Operator):
@@ -69,7 +69,7 @@ class PSK_OT_material_list_move_down(Operator):
         pg = getattr(context.scene, 'psk_export')
         pg.material_list.move(pg.material_list_index, pg.material_list_index + 1)
         pg.material_list_index += 1
-        return {"FINISHED"}
+        return {'FINISHED'}
 
 
 class PSK_OT_export(Operator, ExportHelper):
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 15c0801..eb8866d 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -26,9 +26,9 @@ class PskImportOptions:
 
 
 class ImportBone:
-    """
+    '''
     Intermediate bone type for the purpose of construction.
-    """
+    '''
     def __init__(self, index: int, psk_bone: Psk.Bone):
         self.index: int = index
         self.psk_bone: Psk.Bone = psk_bone
diff --git a/io_scene_psk_psa/psk/reader.py b/io_scene_psk_psa/psk/reader.py
index 6fa2da7..f71a006 100644
--- a/io_scene_psk_psa/psk/reader.py
+++ b/io_scene_psk_psa/psk/reader.py
@@ -23,7 +23,7 @@ def _read_material_references(path: str) -> List[str]:
         return []
     # Do a crude regex match to find the Material list entries.
     contents = property_file_path.read_text()
-    pattern = r"Material\s*=\s*([^\s^,]+)"
+    pattern = r'Material\s*=\s*([^\s^,]+)'
     return re.findall(pattern, contents)
 
 

From 5a870104f1eb0b0b3ea7a32e5ef59c4df112f6f2 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 22 Jan 2024 15:23:16 -0800
Subject: [PATCH 07/31] Added TODO about 4.1 compatibility

---
 io_scene_psk_psa/psk/importer.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index eb8866d..530ba7e 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -222,6 +222,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             for vertex_normal in psk.vertex_normals:
                 normals.append(tuple(vertex_normal))
             mesh_data.normals_split_custom_set_from_vertices(normals)
+            # TODO: This has been removed in 4.1!
             mesh_data.use_auto_smooth = True
         else:
             mesh_data.shade_smooth()

From 9438a35cd1f4d2dca27b910ada25b358317b0dc0 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Wed, 24 Jan 2024 18:46:03 -0800
Subject: [PATCH 08/31] Fixed a bug where any invalid faces would result in
 import failure if also importing vertex colors

---
 io_scene_psk_psa/psk/importer.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 530ba7e..2594e8f 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -204,9 +204,12 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
                     pass
 
             # Map the PSK vertex colors to the face corners.
-            face_corner_colors = np.full((len(psk.faces * 3), 4), 1.0)
+            face_count = len(psk.faces) - len(invalid_face_indices)
+            face_corner_colors = np.full((face_count * 3, 4), 1.0)
             face_corner_color_index = 0
             for face_index, face in enumerate(psk.faces):
+                if face_index in invalid_face_indices:
+                    continue
                 for wedge_index in reversed(face.wedge_indices):
                     face_corner_colors[face_corner_color_index] = psk_vertex_colors[wedge_index]
                     face_corner_color_index += 1

From ced03afafe42e1e3398f31f0fb2faf01a84647ee Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 25 Jan 2024 11:43:13 -0800
Subject: [PATCH 09/31] Added "Scale" option for PSK import

---
 io_scene_psk_psa/psa/importer.py          | 18 +++----
 io_scene_psk_psa/psk/import_/operators.py | 60 ++++++++++++++---------
 io_scene_psk_psa/psk/importer.py          |  8 +++
 3 files changed, 53 insertions(+), 33 deletions(-)

diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 44f2572..d9438f6 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -176,15 +176,15 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             action = bpy.data.actions.new(name=action_name)
 
         # Calculate the target FPS.
-        target_fps = sequence.fps
-        if options.fps_source == 'CUSTOM':
-            target_fps = options.fps_custom
-        elif options.fps_source == 'SCENE':
-            target_fps = context.scene.render.fps
-        elif options.fps_source == 'SEQUENCE':
-            target_fps = sequence.fps
-        else:
-            raise ValueError(f'Unknown FPS source: {options.fps_source}')
+        match options.fps_source:
+            case 'CUSTOM':
+                target_fps = options.fps_custom
+            case 'SCENE':
+                target_fps = context.scene.render.fps
+            case 'SEQUENCE':
+                target_fps = sequence.fps
+            case _:
+                raise ValueError(f'Unknown FPS source: {options.fps_source}')
 
         keyframe_time_dilation = target_fps / sequence.fps
 
diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index 3ebc084..ea57ccc 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -27,8 +27,8 @@ class PSK_OT_import(Operator, ImportHelper):
     should_import_vertex_colors: BoolProperty(
         default=True,
         options=empty_set,
-        name='Vertex Colors',
-        description='Import vertex colors from PSKX files, if available'
+        name='Import Vertex Colors',
+        description='Import vertex colors, if available'
     )
     vertex_color_space: EnumProperty(
         name='Vertex Color Space',
@@ -42,13 +42,13 @@ class PSK_OT_import(Operator, ImportHelper):
     )
     should_import_vertex_normals: BoolProperty(
         default=True,
-        name='Vertex Normals',
+        name='Import Vertex Normals',
         options=empty_set,
         description='Import vertex normals, if available'
     )
     should_import_extra_uvs: BoolProperty(
         default=True,
-        name='Extra UVs',
+        name='Import Extra UVs',
         options=empty_set,
         description='Import extra UV maps, if available'
     )
@@ -63,12 +63,6 @@ class PSK_OT_import(Operator, ImportHelper):
         name='Import Materials',
         options=empty_set,
     )
-    should_reuse_materials: BoolProperty(
-        default=True,
-        name='Reuse Materials',
-        options=empty_set,
-        description='Existing materials with matching names will be reused when available'
-    )
     should_import_skeleton: BoolProperty(
         default=True,
         name='Import Skeleton',
@@ -87,10 +81,15 @@ class PSK_OT_import(Operator, ImportHelper):
     )
     should_import_shape_keys: BoolProperty(
         default=True,
-        name='Shape Keys',
+        name='Import Shape Keys',
         options=empty_set,
         description='Import shape keys, if available'
     )
+    scale: FloatProperty(
+        name='Scale',
+        default=1.0,
+        soft_min=0.0,
+    )
 
     def execute(self, context):
         psk = read_psk(self.filepath)
@@ -106,6 +105,7 @@ class PSK_OT_import(Operator, ImportHelper):
         options.bone_length = self.bone_length
         options.should_import_materials = self.should_import_materials
         options.should_import_shape_keys = self.should_import_shape_keys
+        options.scale = self.scale
 
         result = import_psk(psk, context, options)
 
@@ -120,24 +120,36 @@ class PSK_OT_import(Operator, ImportHelper):
 
     def draw(self, context):
         layout = self.layout
-        layout.prop(self, 'should_import_materials')
+
+        row = layout.row()
+
+        col = row.column()
+        col.use_property_split = True
+        col.use_property_decorate = False
+        col.prop(self, 'scale')
+
         layout.prop(self, 'should_import_mesh')
-        row = layout.column()
-        row.use_property_split = True
-        row.use_property_decorate = False
+
         if self.should_import_mesh:
-            row.prop(self, 'should_import_vertex_normals')
-            row.prop(self, 'should_import_extra_uvs')
-            row.prop(self, 'should_import_vertex_colors')
+            row = layout.row()
+            col = row.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(self, 'should_import_materials', text='Materials')
+            col.prop(self, 'should_import_vertex_normals', text='Vertex Normals')
+            col.prop(self, 'should_import_extra_uvs', text='Extra UVs')
+            col.prop(self, 'should_import_vertex_colors', text='Vertex Colors')
             if self.should_import_vertex_colors:
-                row.prop(self, 'vertex_color_space')
-            row.prop(self, 'should_import_shape_keys')
+                col.prop(self, 'vertex_color_space')
+            col.prop(self, 'should_import_shape_keys', text='Shape Keys')
+
         layout.prop(self, 'should_import_skeleton')
-        row = layout.column()
-        row.use_property_split = True
-        row.use_property_decorate = False
         if self.should_import_skeleton:
-            row.prop(self, 'bone_length')
+            row = layout.row()
+            col = row.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(self, 'bone_length')
 
 
 classes = (
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 2594e8f..e6efe89 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -23,6 +23,7 @@ class PskImportOptions:
         self.should_import_shape_keys = True
         self.bone_length = 1.0
         self.should_import_materials = True
+        self.scale = 1.0
 
 
 class ImportBone:
@@ -51,6 +52,10 @@ class PskImportResult:
 def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
     result = PskImportResult()
     armature_object = None
+    mesh_object = None
+
+    if not options.should_import_mesh and not options.should_import_skeleton:
+        raise Exception('Nothing to import')
 
     if options.should_import_skeleton:
         # ARMATURE
@@ -266,6 +271,9 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             armature_modifier.object = armature_object
             mesh_object.parent = armature_object
 
+    root_object = armature_object if options.should_import_skeleton else mesh_object
+    root_object.scale = (options.scale, options.scale, options.scale)
+
     try:
         bpy.ops.object.mode_set(mode='OBJECT')
     except:

From 0a7804b5abdb8564be9dd033710c53856a598a44 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 27 Jan 2024 00:42:51 -0800
Subject: [PATCH 10/31] Improved reporting of PSK import error when there is
 nothing selected to import

---
 io_scene_psk_psa/psk/import_/operators.py | 4 ++++
 io_scene_psk_psa/psk/importer.py          | 3 ---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index ea57ccc..0a4db97 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -107,6 +107,10 @@ class PSK_OT_import(Operator, ImportHelper):
         options.should_import_shape_keys = self.should_import_shape_keys
         options.scale = self.scale
 
+        if not options.should_import_mesh and not options.should_import_skeleton:
+            self.report({'ERROR'}, 'Nothing to import')
+            return {'CANCELLED'}
+
         result = import_psk(psk, context, options)
 
         if len(result.warnings):
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index e6efe89..8fe4da5 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -54,9 +54,6 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
     armature_object = None
     mesh_object = None
 
-    if not options.should_import_mesh and not options.should_import_skeleton:
-        raise Exception('Nothing to import')
-
     if options.should_import_skeleton:
         # ARMATURE
         armature_data = bpy.data.armatures.new(options.name)

From 9125606bc4ca6cbdf472c17abf0996e9f5bf9646 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Fri, 2 Feb 2024 12:28:45 -0800
Subject: [PATCH 11/31] Fix for issue #71

---
 io_scene_psk_psa/psa/reader.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index e60fbb4..08060b9 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -11,7 +11,7 @@ def _try_fix_cue4parse_issue_103(sequences) -> bool:
     # The issue was that the frame_start_index was not being set correctly, and was always being set to the same value
     # as the frame_count.
     # This fix will eventually be deprecated as it is only necessary for files exported prior to the fix.
-    if len(sequences) == 0 and sequences[0].frame_start_index == sequences[0].frame_count:
+    if len(sequences) > 0 and sequences[0].frame_start_index == sequences[0].frame_count:
         # Manually set the frame_start_index for each sequence. This assumes that the sequences are in order with
         # no shared frames between sequences (all exporters that I know of do this, so it's a safe assumption).
         frame_start_index = 0

From 44100a50f062afea0af59c683e86f1d0ac23beda Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 6 Feb 2024 13:18:19 -0800
Subject: [PATCH 12/31] Added better handling for exporting meshes with
 negative scaling

The exporter now corrects the face normals of meshes with negative
scaling that would otherwise be inverted on export. The face orientation
should now always match what is seen in the viewport.
---
 io_scene_psk_psa/psk/builder.py | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 623ae66..95e4b2d 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -150,6 +150,8 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
 
     for object_index, input_mesh_object in enumerate(input_objects.mesh_objects):
 
+        should_flip_normals = False
+
         # MATERIALS
         material_indices = [material_names.index(material_slot.material.name) for material_slot in input_mesh_object.material_slots]
 
@@ -177,8 +179,16 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
             mesh_object.matrix_world = input_mesh_object.matrix_world
 
             scale = (input_mesh_object.scale.x, input_mesh_object.scale.y, input_mesh_object.scale.z)
-            if any(map(lambda x: x < 0, scale)):
-                result.warnings.append(f'Mesh "{input_mesh_object.name}" has negative scaling which may result in inverted normals.')
+
+            # Negative scaling in Blender results in inverted normals after the scale is applied. However, if the scale
+            # is not applied, the normals will appear unaffected in the viewport. The evaluated mesh data used in the
+            # export will have the scale applied, but this behavior is not obvious to the user.
+            #
+            # In order to have the exporter be as WYSIWYG as possible, we need to check for negative scaling and invert
+            # the normals if necessary. If two axes have negative scaling and the third has positive scaling, the
+            # normals will be correct. We can detect this by checking if the number of negative scaling axes is odd. If
+            # it is, we need to invert the normals of the mesh by swapping the order of the vertices in each face.
+            should_flip_normals = sum(1 for x in scale if x < 0) % 2 == 1
 
             # Copy the vertex groups
             for vertex_group in input_mesh_object.vertex_groups:
@@ -233,6 +243,7 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
 
         # FACES
         poly_groups, groups = mesh_data.calc_smooth_groups(use_bitflags=True)
+        psk_face_start_index = len(psk.faces)
         for f in mesh_data.loop_triangles:
             face = Psk.Face()
             face.material_index = material_indices[f.material_index]
@@ -242,6 +253,11 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
             face.smoothing_groups = poly_groups[f.polygon_index]
             psk.faces.append(face)
 
+        if should_flip_normals:
+            # Invert the normals of the faces.
+            for face in psk.faces[psk_face_start_index:]:
+                face.wedge_indices[0], face.wedge_indices[2] = face.wedge_indices[2], face.wedge_indices[0]
+
         # WEIGHTS
         if armature_object is not None:
             armature_data = typing.cast(Armature, armature_object.data)

From c2d7eecb4f85ba25f95e1e0a974df34b47cefb2f Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 6 Feb 2024 13:26:48 -0800
Subject: [PATCH 13/31] Minor naming changes and refactoring

---
 io_scene_psk_psa/psk/builder.py  | 21 ++++++++++++---------
 io_scene_psk_psa/psk/data.py     | 10 +++++-----
 io_scene_psk_psa/psk/importer.py | 16 ++++++++--------
 3 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 95e4b2d..081be45 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -1,5 +1,8 @@
+from typing import Optional
+
 import bmesh
 import bpy
+import numpy as np
 from bpy.types import Armature
 
 from .data import *
@@ -9,7 +12,7 @@ from ..helpers import *
 class PskInputObjects(object):
     def __init__(self):
         self.mesh_objects = []
-        self.armature_object = None
+        self.armature_object: Optional[Object] = None
 
 
 class PskBuildOptions(object):
@@ -61,7 +64,7 @@ def get_psk_input_objects(context) -> PskInputObjects:
 class PskBuildResult(object):
     def __init__(self):
         self.psk = None
-        self.warnings = []
+        self.warnings: List[str] = []
 
 
 def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
@@ -217,11 +220,11 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
         # Build a list of non-unique wedges.
         wedges = []
         for loop_index, loop in enumerate(mesh_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)
+            wedges.append(Psk.Wedge(
+                point_index=loop.vertex_index + vertex_offset,
+                u=uv_layer[loop_index].uv[0],
+                v=1.0 - uv_layer[loop_index].uv[1]
+            ))
 
         # Assign material indices to the wedges.
         for triangle in mesh_data.loop_triangles:
@@ -229,8 +232,8 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
                 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(mesh_data.loops)
+        wedge_indices = dict()
+        loop_wedge_indices = np.full(len(mesh_data.loops), -1)
         for loop_index, wedge in enumerate(wedges):
             wedge_hash = hash(wedge)
             if wedge_hash in wedge_indices:
diff --git a/io_scene_psk_psa/psk/data.py b/io_scene_psk_psa/psk/data.py
index 8df58fa..03bd49a 100644
--- a/io_scene_psk_psa/psk/data.py
+++ b/io_scene_psk_psa/psk/data.py
@@ -5,11 +5,11 @@ 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 __init__(self, point_index: int, u: float, v: float, material_index: int = 0):
+            self.point_index: int = point_index
+            self.u: float = u
+            self.v: float = v
+            self.material_index = material_index
 
         def __hash__(self):
             return hash(f'{self.point_index}-{self.u}-{self.v}-{self.material_index}')
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 8fe4da5..c00ff07 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -166,38 +166,38 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
         bm.to_mesh(mesh_data)
 
         # TEXTURE COORDINATES
-        data_index = 0
+        uv_layer_data_index = 0
         uv_layer = mesh_data.uv_layers.new(name='VTXW0000')
         for face_index, face in enumerate(psk.faces):
             if face_index in invalid_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
+                uv_layer.data[uv_layer_data_index].uv = wedge.u, 1.0 - wedge.v
+                uv_layer_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_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 invalid_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
+                        uv_layer.data[uv_layer_data_index].uv = u, 1.0 - v
+                        uv_layer_data_index += 1
                 wedge_index_offset += len(psk.wedges)
 
         # VERTEX COLORS
         if psk.has_vertex_colors and options.should_import_vertex_colors:
             # Convert vertex colors to sRGB if necessary.
             psk_vertex_colors = np.zeros((len(psk.vertex_colors), 4))
-            for i in range(len(psk.vertex_colors)):
-                psk_vertex_colors[i,:] = psk.vertex_colors[i].normalized()
+            for vertex_color_index in range(len(psk.vertex_colors)):
+                psk_vertex_colors[vertex_color_index,:] = psk.vertex_colors[vertex_color_index].normalized()
             match options.vertex_color_space:
                 case 'SRGBA':
                     for i in range(psk_vertex_colors.shape[0]):

From eb8cee697332a1e3f46bffb0f81eebeb5badb3a5 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 6 Feb 2024 13:27:16 -0800
Subject: [PATCH 14/31] Markers with empty names are now ignored as export
 options

---
 io_scene_psk_psa/psa/export/operators.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/io_scene_psk_psa/psa/export/operators.py b/io_scene_psk_psa/psa/export/operators.py
index 115451f..a44f02c 100644
--- a/io_scene_psk_psa/psa/export/operators.py
+++ b/io_scene_psk_psa/psa/export/operators.py
@@ -47,7 +47,7 @@ def update_actions_and_timeline_markers(context: Context, armature: Armature):
         if not is_action_for_armature(armature, action):
             continue
 
-        if not action.name.startswith('#'):
+        if action.name != '' and not action.name.startswith('#'):
             for (name, frame_start, frame_end) in get_sequences_from_action(action):
                 item = pg.action_list.add()
                 item.action = action
@@ -60,7 +60,7 @@ def update_actions_and_timeline_markers(context: Context, armature: Armature):
         # Pose markers are not guaranteed to be in frame-order, so make sure that they are.
         pose_markers = sorted(action.pose_markers, key=lambda x: x.frame)
         for pose_marker_index, pose_marker in enumerate(pose_markers):
-            if pose_marker.name.startswith('#'):
+            if pose_marker.name.strip() == '' or pose_marker.name.startswith('#'):
                 continue
             for (name, frame_start, frame_end) in get_sequences_from_action_pose_marker(action, pose_markers, pose_marker, pose_marker_index):
                 item = pg.action_list.add()
@@ -78,7 +78,7 @@ def update_actions_and_timeline_markers(context: Context, armature: Armature):
     for marker_name in marker_names:
         if marker_name not in sequence_frame_ranges:
             continue
-        if marker_name.startswith('#'):
+        if marker_name.strip() == '' or marker_name.startswith('#'):
             continue
         frame_start, frame_end = sequence_frame_ranges[marker_name]
         sequences = get_sequences_from_name_and_frame_range(marker_name, frame_start, frame_end)

From 82eaddf1cb66e747c264b829f7d2857801dc78fc Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 12 Feb 2024 11:06:52 -0800
Subject: [PATCH 15/31] Increased max bone count to int32 limit

---
 io_scene_psk_psa/psk/writer.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psk/writer.py b/io_scene_psk_psa/psk/writer.py
index eec3234..5dae319 100644
--- a/io_scene_psk_psa/psk/writer.py
+++ b/io_scene_psk_psa/psk/writer.py
@@ -6,7 +6,7 @@ from ..data import Section, Vector3
 
 MAX_WEDGE_COUNT = 65536
 MAX_POINT_COUNT = 4294967296
-MAX_BONE_COUNT = 256
+MAX_BONE_COUNT = 2147483647
 MAX_MATERIAL_COUNT = 256
 
 

From f7bbe911ea5de7cdd528bc8cd261d1c6f361d72c Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 13 Feb 2024 00:19:12 -0800
Subject: [PATCH 16/31] Removed `use_auto_smooth`...again

---
 io_scene_psk_psa/psk/importer.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index c00ff07..4f6551e 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -227,8 +227,6 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             for vertex_normal in psk.vertex_normals:
                 normals.append(tuple(vertex_normal))
             mesh_data.normals_split_custom_set_from_vertices(normals)
-            # TODO: This has been removed in 4.1!
-            mesh_data.use_auto_smooth = True
         else:
             mesh_data.shade_smooth()
 

From 11bf205fe2aaf16ffed1acfcd1cc4fa770eba674 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 13 Feb 2024 14:03:04 -0800
Subject: [PATCH 17/31] Added PSA resampling on import + some fixes for 4.1

---
 io_scene_psk_psa/psa/export/operators.py  | 19 +++---
 io_scene_psk_psa/psa/import_/operators.py | 24 ++------
 io_scene_psk_psa/psa/importer.py          | 74 +++++++++++++++++++----
 io_scene_psk_psa/psk/import_/operators.py | 27 +++++----
 4 files changed, 92 insertions(+), 52 deletions(-)

diff --git a/io_scene_psk_psa/psa/export/operators.py b/io_scene_psk_psa/psa/export/operators.py
index a44f02c..0aa46bb 100644
--- a/io_scene_psk_psa/psa/export/operators.py
+++ b/io_scene_psk_psa/psa/export/operators.py
@@ -91,15 +91,16 @@ def update_actions_and_timeline_markers(context: Context, armature: Armature):
 
 
 def get_sequence_fps(context: Context, fps_source: str, fps_custom: float, actions: Iterable[Action]) -> float:
-    if fps_source == 'SCENE':
-        return context.scene.render.fps
-    elif fps_source == 'CUSTOM':
-        return fps_custom
-    elif fps_source == 'ACTION_METADATA':
-        # Get the minimum value of action metadata FPS values.
-        return min([action.psa_export.fps for action in actions])
-    else:
-        raise RuntimeError(f'Invalid FPS source "{fps_source}"')
+    match fps_source:
+        case 'SCENE':
+            return context.scene.render.fps
+        case 'CUSTOM':
+            return fps_custom
+        case 'ACTION_METADATA':
+            # Get the minimum value of action metadata FPS values.
+            return min([action.psa_export.fps for action in actions])
+        case _:
+            raise RuntimeError(f'Invalid FPS source "{fps_source}"')
 
 
 def get_animation_data_object(context: Context) -> Object:
diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index 7891a32..c588208 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -2,7 +2,7 @@ import os
 from pathlib import Path
 
 from bpy.props import StringProperty
-from bpy.types import Operator, Event, Context
+from bpy.types import Operator, Event, Context, FileHandler
 from bpy_extras.io_utils import ImportHelper
 
 from .properties import get_visible_sequences
@@ -89,23 +89,6 @@ class PSA_OT_import_sequences_deselect_all(Operator):
         return {'FINISHED'}
 
 
-class PSA_OT_import_select_file(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: StringProperty(subtype='FILE_PATH')
-    filter_glob: StringProperty(default='*.psa', options={'HIDDEN'})
-
-    def execute(self, context):
-        getattr(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'}
-
-
 def load_psa_file(context, filepath: str):
     pg = context.scene.psa_import
     pg.sequence_list.clear()
@@ -270,10 +253,13 @@ class PSA_OT_import(Operator, ImportHelper):
             col.prop(pg, 'action_name_prefix')
 
 
+class PSA_FH_import(FileHandler):
+
+
+
 classes = (
     PSA_OT_import_sequences_select_all,
     PSA_OT_import_sequences_deselect_all,
     PSA_OT_import_sequences_from_text,
     PSA_OT_import,
-    PSA_OT_import_select_file,
 )
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index d9438f6..d2f5a18 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -1,8 +1,9 @@
+import math
 import typing
 from typing import List, Optional
 
 import bpy
-import numpy
+import numpy as np
 from bpy.types import FCurve, Object, Context
 from mathutils import Vector, Quaternion
 
@@ -80,6 +81,50 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
     return None
 
 
+def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, target_frame_count: int):
+    '''
+    Resamples the sequence data matrix to the target frame count.
+    @param sequence_data_matrix: FxBx7 matrix where F is the number of frames, B is the number of bones, and X is the
+    number of data elements per bone.
+    @param target_frame_count: The number of frames to resample to.
+    @return: The resampled sequence data matrix, or sequence_data_matrix if no resampling is necessary.
+    '''
+    def get_sample_times(source_frame_count: int, target_frame_count: int) -> typing.Iterable[float]:
+        time = 0.0
+        time_step = source_frame_count / target_frame_count
+        while time <= target_frame_count - 1:
+            yield time
+            time += time_step
+        yield 1.0
+
+    source_frame_count, bone_count = sequence_data_matrix.shape[:1]
+
+    if target_frame_count == source_frame_count:
+        # No resampling is necessary.
+        return sequence_data_matrix
+
+    resampled_sequence_data_matrix = np.zeros((target_frame_count, bone_count, 7), dtype=float)
+    sample_times = get_sample_times(source_frame_count, target_frame_count)
+
+    for frame_index, sample_time in enumerate(sample_times):
+        if sample_time % 1.0 == 0.0:
+            # Sample time has no fractional part, so just copy the frame.
+            resampled_sequence_data_matrix[frame_index, :, :] = sequence_data_matrix[int(sample_time), :, :]
+        else:
+            # Sample time has a fractional part, so interpolate between two frames.
+            for bone_index in range(bone_count):
+                frame_index = int(sample_time)
+                source_frame_1_data = sequence_data_matrix[frame_index, bone_index, :]
+                source_frame_2_data = sequence_data_matrix[frame_index + 1, bone_index, :]
+                factor = sample_time - frame_index
+                q = Quaternion((source_frame_1_data[:4])).slerp(Quaternion((source_frame_2_data[:4])), factor)
+                q.normalize()
+                l = Vector(source_frame_1_data[4:]).lerp(Vector(source_frame_2_data[4:]), factor)
+                resampled_sequence_data_matrix[frame_index, bone_index, :] = q.w, q.x, q.y, q.z, l.x, l.y, l.z
+
+    return resampled_sequence_data_matrix
+
+
 def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object, options: PsaImportOptions) -> PsaImportResult:
     result = PsaImportResult()
     sequences = [psa_reader.sequences[x] for x in options.sequence_names]
@@ -186,12 +231,9 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             case _:
                 raise ValueError(f'Unknown FPS source: {options.fps_source}')
 
-        keyframe_time_dilation = target_fps / sequence.fps
-
         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])
+            # Remove existing f-curves.
+            action.fcurves.clear()
 
             # 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():
@@ -225,19 +267,27 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
                     # Calculate the local-space key data for the bone.
                     sequence_data_matrix[frame_index, bone_index] = _calculate_fcurve_data(import_bone, key_data)
 
-            # Write the keyframes out.
-            fcurve_data = numpy.zeros(2 * sequence.frame_count, dtype=float)
+            # Resample the sequence data to the target FPS.
+            # TODO: target frame count can be fractional.
+            target_frame_count = math.ceil(sequence.frame_count * (target_fps / sequence.fps))
+
+            # Write the keyframes out.
+            # Note that the f-curve data consists of alternating time and value data.
+            fcurve_data = np.zeros(2 * target_frame_count, dtype=float)
+            fcurve_data[0::2] = range(0, target_frame_count)
+
+            # Resample the sequence data matrix to the target frame count.
+            # If the target frame count is the same as the source frame count, this will be a no-op.
+            resampled_sequence_data_matrix = _resample_sequence_data_matrix(sequence_data_matrix, target_frame_count)
 
-            # Populate the keyframe time data.
-            fcurve_data[0::2] = [x * keyframe_time_dilation for x in range(sequence.frame_count)]
             for bone_index, import_bone in enumerate(import_bones):
                 if import_bone is None:
                     continue
                 for fcurve_index, fcurve in enumerate(import_bone.fcurves):
                     if fcurve is None:
                         continue
-                    fcurve_data[1::2] = sequence_data_matrix[:, bone_index, fcurve_index]
-                    fcurve.keyframe_points.add(sequence.frame_count)
+                    fcurve_data[1::2] = resampled_sequence_data_matrix[:, bone_index, fcurve_index]
+                    fcurve.keyframe_points.add(target_frame_count)
                     fcurve.keyframe_points.foreach_set('co', fcurve_data)
                     for fcurve_keyframe in fcurve.keyframe_points:
                         fcurve_keyframe.interpolation = 'LINEAR'
diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index 741775b..3cebfa4 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -11,15 +11,15 @@ from ..reader import read_psk
 empty_set = set()
 
 
-class PSX_FH_psk(FileHandler):
-    bl_idname = 'PSX_FH_psk'
-    bl_label = 'Unreal PSK/PSKX'
+class PSK_FH_import(FileHandler):
+    bl_idname = 'PSK_FH_import'
+    bl_label = 'File handler for Unreal PSK/PSKX import'
     bl_import_operator = 'import_scene.psk'
-    bl_file_extensions = '.psk;.pskx'
+    bl_file_extensions = '.psk'
 
     @classmethod
     def poll_drop(cls, context: Context):
-        return context.area.type == 'VIEW_3D'
+        return context.area and context.area.type == 'VIEW_3D'
 
 
 class PSK_OT_import(Operator, ImportHelper):
@@ -143,10 +143,11 @@ class PSK_OT_import(Operator, ImportHelper):
         col.use_property_decorate = False
         col.prop(self, 'scale')
 
-        layout.prop(self, 'should_import_mesh')
+        mesh_header, mesh_panel = layout.panel('mesh_panel_id', default_closed=False)
+        mesh_header.prop(self, 'should_import_mesh')
 
-        if self.should_import_mesh:
-            row = layout.row()
+        if mesh_panel and self.should_import_mesh:
+            row = mesh_panel.row()
             col = row.column()
             col.use_property_split = True
             col.use_property_decorate = False
@@ -158,9 +159,11 @@ class PSK_OT_import(Operator, ImportHelper):
                 col.prop(self, 'vertex_color_space')
             col.prop(self, 'should_import_shape_keys', text='Shape Keys')
 
-        layout.prop(self, 'should_import_skeleton')
-        if self.should_import_skeleton:
-            row = layout.row()
+        skeleton_header, skeleton_panel = layout.panel('skeleton_panel_id', default_closed=False)
+        skeleton_header.prop(self, 'should_import_skeleton')
+
+        if skeleton_panel and self.should_import_skeleton:
+            row = skeleton_panel.row()
             col = row.column()
             col.use_property_split = True
             col.use_property_decorate = False
@@ -169,5 +172,5 @@ class PSK_OT_import(Operator, ImportHelper):
 
 classes = (
     PSK_OT_import,
-    PSX_FH_psk,
+    PSK_FH_import,
 )

From ce1a4112005324caf333755b2a23bacc120f1731 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 17 Feb 2024 23:01:42 -0800
Subject: [PATCH 18/31] Fix for issue #76

---
 io_scene_psk_psa/psa/export/operators.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psa/export/operators.py b/io_scene_psk_psa/psa/export/operators.py
index a44f02c..aa5d88d 100644
--- a/io_scene_psk_psa/psa/export/operators.py
+++ b/io_scene_psk_psa/psa/export/operators.py
@@ -110,7 +110,7 @@ def get_animation_data_object(context: Context) -> Object:
     if active_object.type != 'ARMATURE':
         raise RuntimeError('Selected object must be an Armature')
 
-    if pg.should_override_animation_data:
+    if pg.sequence_source != 'ACTIONS' and pg.should_override_animation_data:
         animation_data_object = pg.animation_data_override
     else:
         animation_data_object = active_object

From ead1e3c793e317d5be1509805cf5be4a1fe2260a Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Wed, 28 Feb 2024 00:51:33 -0800
Subject: [PATCH 19/31] Initial commit of UT99 poly flags

---
 io_scene_psk_psa/__init__.py              |  8 +++++
 io_scene_psk_psa/psk/builder.py           | 17 +++++-----
 io_scene_psk_psa/psk/export/operators.py  | 14 ++++-----
 io_scene_psk_psa/psk/export/properties.py |  6 ++--
 io_scene_psk_psa/psk/export/ui.py         |  2 +-
 io_scene_psk_psa/psk/properties.py        | 38 +++++++++++++++++++++++
 io_scene_psk_psa/psk/ui.py                | 28 +++++++++++++++++
 io_scene_psk_psa/types.py                 |  2 +-
 8 files changed, 96 insertions(+), 19 deletions(-)
 create mode 100644 io_scene_psk_psa/psk/properties.py
 create mode 100644 io_scene_psk_psa/psk/ui.py

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index 7570fe9..4076dd9 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -24,6 +24,8 @@ if 'bpy' in locals():
     importlib.reload(psk_writer)
     importlib.reload(psk_builder)
     importlib.reload(psk_importer)
+    importlib.reload(psk_properties)
+    importlib.reload(psk_ui)
     importlib.reload(psk_export_properties)
     importlib.reload(psk_export_operators)
     importlib.reload(psk_export_ui)
@@ -50,6 +52,8 @@ else:
     from .psk import writer as psk_writer
     from .psk import builder as psk_builder
     from .psk import importer as psk_importer
+    from .psk import properties as psk_properties
+    from .psk import ui as psk_ui
     from .psk.export import properties as psk_export_properties
     from .psk.export import operators as psk_export_operators
     from .psk.export import ui as psk_export_ui
@@ -72,6 +76,8 @@ import bpy
 from bpy.props import PointerProperty
 
 classes = psx_types.classes +\
+          psk_properties.classes +\
+          psk_ui.classes +\
           psk_import_operators.classes +\
           psk_export_properties.classes +\
           psk_export_operators.classes +\
@@ -107,6 +113,7 @@ def register():
     bpy.types.TOPBAR_MT_file_import.append(psk_import_menu_func)
     bpy.types.TOPBAR_MT_file_export.append(psa_export_menu_func)
     bpy.types.TOPBAR_MT_file_import.append(psa_import_menu_func)
+    bpy.types.Material.psk = PointerProperty(type=psk_properties.PSX_PG_material)
     bpy.types.Scene.psa_import = PointerProperty(type=psa_import_properties.PSA_PG_import)
     bpy.types.Scene.psa_export = PointerProperty(type=psa_export_properties.PSA_PG_export)
     bpy.types.Scene.psk_export = PointerProperty(type=psk_export_properties.PSK_PG_export)
@@ -114,6 +121,7 @@ def register():
 
 
 def unregister():
+    del bpy.types.Material.psk
     del bpy.types.Scene.psa_import
     del bpy.types.Scene.psa_export
     del bpy.types.Scene.psk_export
diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 081be45..2ba6c34 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -3,9 +3,10 @@ from typing import Optional
 import bmesh
 import bpy
 import numpy as np
-from bpy.types import Armature
+from bpy.types import Armature, Material
 
 from .data import *
+from .properties import get_poly_flags
 from ..helpers import *
 
 
@@ -20,7 +21,7 @@ class PskBuildOptions(object):
         self.bone_filter_mode = 'ALL'
         self.bone_collection_indices: List[int] = []
         self.use_raw_mesh_data = True
-        self.material_names: List[str] = []
+        self.materials: List[Material] = []
         self.should_enforce_bone_name_restrictions = False
 
 
@@ -138,19 +139,21 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
             psk.bones.append(psk_bone)
 
     # MATERIALS
-    material_names = options.material_names
-
-    for material_name in material_names:
+    for material in options.materials:
         psk_material = Psk.Material()
         try:
-            psk_material.name = bytes(material_name, encoding='windows-1252')
+            psk_material.name = bytes(material.name, encoding='windows-1252')
         except UnicodeEncodeError:
-            raise RuntimeError(f'Material name "{material_name}" contains characters that cannot be encoded in the Windows-1252 codepage')
+            raise RuntimeError(f'Material name "{material.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
         psk_material.texture_index = len(psk.materials)
+        psk_material.poly_flags = get_poly_flags(material.psk)
+        print(psk_material.name, psk_material.poly_flags)
         psk.materials.append(psk_material)
 
     context.window_manager.progress_begin(0, len(input_objects.mesh_objects))
 
+    material_names = [m.name for m in options.materials]
+
     for object_index, input_mesh_object in enumerate(input_objects.mesh_objects):
 
         should_flip_normals = False
diff --git a/io_scene_psk_psa/psk/export/operators.py b/io_scene_psk_psa/psk/export/operators.py
index a902b27..98d8f4f 100644
--- a/io_scene_psk_psa/psk/export/operators.py
+++ b/io_scene_psk_psa/psk/export/operators.py
@@ -20,19 +20,19 @@ def is_bone_filter_mode_item_available(context, identifier):
 def populate_material_list(mesh_objects, material_list):
     material_list.clear()
 
-    material_names = []
+    materials = []
     for mesh_object in mesh_objects:
         for i, material_slot in enumerate(mesh_object.material_slots):
             material = material_slot.material
             # TODO: put this in the poll arg?
             if material is None:
                 raise RuntimeError('Material slot cannot be empty (index ' + str(i) + ')')
-            if material.name not in material_names:
-                material_names.append(material.name)
+            if material not in materials:
+                materials.append(material)
 
-    for index, material_name in enumerate(material_names):
+    for index, material in enumerate(materials):
         m = material_list.add()
-        m.material_name = material_name
+        m.material = material
         m.index = index
 
 
@@ -159,9 +159,9 @@ class PSK_OT_export(Operator, ExportHelper):
         options.bone_filter_mode = pg.bone_filter_mode
         options.bone_collection_indices = [x.index for x in pg.bone_collection_list if x.is_selected]
         options.use_raw_mesh_data = pg.use_raw_mesh_data
-        options.material_names = [m.material_name for m in pg.material_list]
+        options.materials = [m.material for m in pg.material_list]
         options.should_enforce_bone_name_restrictions = pg.should_enforce_bone_name_restrictions
-
+        
         try:
             result = build_psk(context, options)
             for warning in result.warnings:
diff --git a/io_scene_psk_psa/psk/export/properties.py b/io_scene_psk_psa/psk/export/properties.py
index 8382d01..bdb6493 100644
--- a/io_scene_psk_psa/psk/export/properties.py
+++ b/io_scene_psk_psa/psk/export/properties.py
@@ -1,11 +1,11 @@
-from bpy.props import EnumProperty, CollectionProperty, IntProperty, BoolProperty, StringProperty
-from bpy.types import PropertyGroup
+from bpy.props import EnumProperty, CollectionProperty, IntProperty, BoolProperty, PointerProperty
+from bpy.types import PropertyGroup, Material
 
 from ...types import PSX_PG_bone_collection_list_item
 
 
 class PSK_PG_material_list_item(PropertyGroup):
-    material_name: StringProperty()
+    material: PointerProperty(type=Material)
     index: IntProperty()
 
 
diff --git a/io_scene_psk_psa/psk/export/ui.py b/io_scene_psk_psa/psk/export/ui.py
index 6a7a056..4fa55af 100644
--- a/io_scene_psk_psa/psk/export/ui.py
+++ b/io_scene_psk_psa/psk/export/ui.py
@@ -4,7 +4,7 @@ from bpy.types import UIList
 class PSK_UL_materials(UIList):
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
         row = layout.row()
-        row.label(text=str(getattr(item, 'material_name')), icon='MATERIAL')
+        row.prop(item.material, 'name', text='', emboss=False, icon_value=layout.icon(item.material))
 
 
 classes = (
diff --git a/io_scene_psk_psa/psk/properties.py b/io_scene_psk_psa/psk/properties.py
new file mode 100644
index 0000000..2719336
--- /dev/null
+++ b/io_scene_psk_psa/psk/properties.py
@@ -0,0 +1,38 @@
+from bpy.props import EnumProperty
+from bpy.types import PropertyGroup
+
+mesh_triangle_types_items = (
+    ('MTT_Normal', 'Normal', 'Normal one-sided', 0),
+    ('MTT_NormalTwoSided', 'Normal Two-Sided', 'Normal but two-sided', 1),
+    ('MTT_Translucent', 'Translucent', 'Translucent two-sided', 2),
+    ('MTT_Masked', 'Masked', 'Masked two-sided', 3),
+    ('MTT_Modulate', 'Modulate', 'Modulation blended two-sided', 4),
+    ('MTT_Placeholder', 'Placeholder', 'Placeholder triangle for positioning weapon. Invisible', 8),
+)
+
+mesh_triangle_bit_flags_items = (
+    ('MTT_Unlit', 'Unlit', 'Full brightness, no lighting', 16),
+    ('MTT_Flat', 'Flat', 'Flat surface, don\'t do bMeshCurvy thing', 32),
+    ('MTT_Environment', 'Environment', 'Environment mapped', 64),
+    ('MTT_NoSmooth', 'No Smooth', 'No bilinear filtering on this poly\'s texture', 128),
+)
+
+class PSX_PG_material(PropertyGroup):
+    mesh_triangle_type: EnumProperty(items=mesh_triangle_types_items, name='Triangle Type')
+    mesh_triangle_bit_flags: EnumProperty(items=mesh_triangle_bit_flags_items, name='Triangle Bit Flags',
+                                          options={'ENUM_FLAG'})
+
+mesh_triangle_types_items_dict = {item[0]: item[3] for item in mesh_triangle_types_items}
+mesh_triangle_bit_flags_items_dict = {item[0]: item[3] for item in mesh_triangle_bit_flags_items}
+
+
+def get_poly_flags(material: PSX_PG_material) -> int:
+    poly_flags = 0
+    poly_flags |= mesh_triangle_types_items_dict[material.mesh_triangle_type]
+    for flag in material.mesh_triangle_bit_flags:
+        poly_flags |= mesh_triangle_bit_flags_items_dict[flag]
+    return poly_flags
+
+classes = (
+    PSX_PG_material,
+)
diff --git a/io_scene_psk_psa/psk/ui.py b/io_scene_psk_psa/psk/ui.py
new file mode 100644
index 0000000..a3577b0
--- /dev/null
+++ b/io_scene_psk_psa/psk/ui.py
@@ -0,0 +1,28 @@
+from bpy.types import Panel
+
+
+class PSK_PT_material(Panel):
+    bl_label = 'PSK Material'
+    bl_idname = 'PSK_PT_material'
+    bl_space_type = 'PROPERTIES'
+    bl_region_type = 'WINDOW'
+    bl_context = 'material'
+    bl_options = {'DEFAULT_CLOSED'}
+
+    @classmethod
+    def poll(cls, context):
+        return context.material is not None
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+        material = context.material
+        layout.prop(material.psk, 'mesh_triangle_type')
+        col = layout.column()
+        col.prop(material.psk, 'mesh_triangle_bit_flags', expand=True, text='Flags')
+
+
+classes = (
+    PSK_PT_material,
+)
diff --git a/io_scene_psk_psa/types.py b/io_scene_psk_psa/types.py
index ae3e9a9..4f13902 100644
--- a/io_scene_psk_psa/types.py
+++ b/io_scene_psk_psa/types.py
@@ -51,5 +51,5 @@ classes = (
     PSX_PG_action_export,
     PSX_PG_bone_collection_list_item,
     PSX_UL_bone_collection_list,
-    PSX_PT_action
+    PSX_PT_action,
 )

From 14116963bbf453cb66f9a5e6cc00c2dc33288918 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Wed, 28 Feb 2024 23:21:31 -0800
Subject: [PATCH 20/31] Incremented version to 6.2.0

---
 io_scene_psk_psa/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index 4076dd9..a5f5c6a 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -3,7 +3,7 @@ from bpy.app.handlers import persistent
 bl_info = {
     'name': 'PSK/PSA Importer/Exporter',
     'author': 'Colin Basnett, Yurii Ti',
-    'version': (6, 1, 2),
+    'version': (6, 2, 0),
     'blender': (4, 0, 0),
     'description': 'PSK/PSA Import/Export (.psk/.psa)',
     'warning': '',

From 15e2c6ccdded3fbd2c506754423ef0f1ecf23efc Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 29 Feb 2024 00:32:42 -0800
Subject: [PATCH 21/31] Importing PSKs with poly flags now works

---
 io_scene_psk_psa/psk/builder.py    |  6 ++---
 io_scene_psk_psa/psk/importer.py   |  4 ++++
 io_scene_psk_psa/psk/properties.py | 38 +++++++++++++++++++-----------
 3 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 2ba6c34..4ab52d5 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -6,7 +6,7 @@ import numpy as np
 from bpy.types import Armature, Material
 
 from .data import *
-from .properties import get_poly_flags
+from .properties import triangle_type_and_bit_flags_to_poly_flags
 from ..helpers import *
 
 
@@ -146,8 +146,8 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
         except UnicodeEncodeError:
             raise RuntimeError(f'Material name "{material.name}" contains characters that cannot be encoded in the Windows-1252 codepage')
         psk_material.texture_index = len(psk.materials)
-        psk_material.poly_flags = get_poly_flags(material.psk)
-        print(psk_material.name, psk_material.poly_flags)
+        psk_material.poly_flags = triangle_type_and_bit_flags_to_poly_flags(material.psk.mesh_triangle_type,
+                                                                            material.psk.mesh_triangle_bit_flags)
         psk.materials.append(psk_material)
 
     context.window_manager.progress_begin(0, len(input_objects.mesh_objects))
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index c00ff07..e9e6e50 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -7,6 +7,7 @@ from bpy.types import VertexGroup
 from mathutils import Quaternion, Vector, Matrix
 
 from .data import Psk
+from .properties import poly_flags_to_triangle_type_and_bit_flags
 from ..helpers import rgb_to_srgb, is_bdk_addon_loaded
 
 
@@ -134,6 +135,9 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
                 else:
                     # Just create a blank material.
                     material = bpy.data.materials.new(material_name)
+                    mesh_triangle_type, mesh_triangle_bit_flags = poly_flags_to_triangle_type_and_bit_flags(psk_material.poly_flags)
+                    material.psk.mesh_triangle_type = mesh_triangle_type
+                    material.psk.mesh_triangle_bit_flags = mesh_triangle_bit_flags
                     material.use_nodes = True
                 mesh_data.materials.append(material)
 
diff --git a/io_scene_psk_psa/psk/properties.py b/io_scene_psk_psa/psk/properties.py
index 2719336..917f390 100644
--- a/io_scene_psk_psa/psk/properties.py
+++ b/io_scene_psk_psa/psk/properties.py
@@ -2,19 +2,19 @@ from bpy.props import EnumProperty
 from bpy.types import PropertyGroup
 
 mesh_triangle_types_items = (
-    ('MTT_Normal', 'Normal', 'Normal one-sided', 0),
-    ('MTT_NormalTwoSided', 'Normal Two-Sided', 'Normal but two-sided', 1),
-    ('MTT_Translucent', 'Translucent', 'Translucent two-sided', 2),
-    ('MTT_Masked', 'Masked', 'Masked two-sided', 3),
-    ('MTT_Modulate', 'Modulate', 'Modulation blended two-sided', 4),
-    ('MTT_Placeholder', 'Placeholder', 'Placeholder triangle for positioning weapon. Invisible', 8),
+    ('NORMAL', 'Normal', 'Normal one-sided', 0),
+    ('NORMAL_TWO_SIDED', 'Normal Two-Sided', 'Normal but two-sided', 1),
+    ('TRANSLUCENT', 'Translucent', 'Translucent two-sided', 2),
+    ('MASKED', 'Masked', 'Masked two-sided', 3),
+    ('MODULATE', 'Modulate', 'Modulation blended two-sided', 4),
+    ('PLACEHOLDER', 'Placeholder', 'Placeholder triangle for positioning weapon. Invisible', 8),
 )
 
 mesh_triangle_bit_flags_items = (
-    ('MTT_Unlit', 'Unlit', 'Full brightness, no lighting', 16),
-    ('MTT_Flat', 'Flat', 'Flat surface, don\'t do bMeshCurvy thing', 32),
-    ('MTT_Environment', 'Environment', 'Environment mapped', 64),
-    ('MTT_NoSmooth', 'No Smooth', 'No bilinear filtering on this poly\'s texture', 128),
+    ('UNLIT', 'Unlit', 'Full brightness, no lighting', 16),
+    ('FLAT', 'Flat', 'Flat surface, don\'t do bMeshCurvy thing', 32),
+    ('ENVIRONMENT', 'Environment', 'Environment mapped', 64),
+    ('NO_SMOOTH', 'No Smooth', 'No bilinear filtering on this poly\'s texture', 128),
 )
 
 class PSX_PG_material(PropertyGroup):
@@ -26,13 +26,23 @@ mesh_triangle_types_items_dict = {item[0]: item[3] for item in mesh_triangle_typ
 mesh_triangle_bit_flags_items_dict = {item[0]: item[3] for item in mesh_triangle_bit_flags_items}
 
 
-def get_poly_flags(material: PSX_PG_material) -> int:
+def triangle_type_and_bit_flags_to_poly_flags(mesh_triangle_type: str, mesh_triangle_bit_flags: set[str]) -> int:
     poly_flags = 0
-    poly_flags |= mesh_triangle_types_items_dict[material.mesh_triangle_type]
-    for flag in material.mesh_triangle_bit_flags:
-        poly_flags |= mesh_triangle_bit_flags_items_dict[flag]
+    poly_flags |= mesh_triangle_types_items_dict.get(mesh_triangle_type, 0)
+    for flag in mesh_triangle_bit_flags:
+        poly_flags |= mesh_triangle_bit_flags_items_dict.get(flag, 0)
     return poly_flags
 
+
+def poly_flags_to_triangle_type_and_bit_flags(poly_flags: int) -> (str, set[str]):
+    try:
+        triangle_type = next(item[0] for item in mesh_triangle_types_items if item[3] == (poly_flags & 15))
+    except StopIteration:
+        triangle_type = 'NORMAL'
+    triangle_bit_flags = {item[0] for item in mesh_triangle_bit_flags_items if item[3] & poly_flags}
+    return triangle_type, triangle_bit_flags
+
+
 classes = (
     PSX_PG_material,
 )

From 5d3c7cc5706a2406e52e7d451fae84646efee967 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 29 Feb 2024 16:03:47 -0800
Subject: [PATCH 22/31] Fixed PSA import resampling logic

---
 io_scene_psk_psa/__init__.py     |  1 +
 io_scene_psk_psa/psa/importer.py | 41 ++++++++++++++++----------------
 2 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index 7570fe9..4b2589f 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -34,6 +34,7 @@ if 'bpy' in locals():
     importlib.reload(psa_reader)
     importlib.reload(psa_writer)
     importlib.reload(psa_builder)
+    importlib.reload(psa_importer)
     importlib.reload(psa_export_properties)
     importlib.reload(psa_export_operators)
     importlib.reload(psa_export_ui)
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index d2f5a18..aad193f 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -1,4 +1,3 @@
-import math
 import typing
 from typing import List, Optional
 
@@ -81,7 +80,7 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
     return None
 
 
-def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, target_frame_count: int):
+def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, time_step: float = 1.0) -> np.ndarray:
     '''
     Resamples the sequence data matrix to the target frame count.
     @param sequence_data_matrix: FxBx7 matrix where F is the number of frames, B is the number of bones, and X is the
@@ -89,38 +88,40 @@ def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, target_fram
     @param target_frame_count: The number of frames to resample to.
     @return: The resampled sequence data matrix, or sequence_data_matrix if no resampling is necessary.
     '''
-    def get_sample_times(source_frame_count: int, target_frame_count: int) -> typing.Iterable[float]:
+    def get_sample_times(source_frame_count: int, time_step: float) -> typing.Iterable[float]:
+        # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
+        #  fractional frame).
         time = 0.0
-        time_step = source_frame_count / target_frame_count
-        while time <= target_frame_count - 1:
+        while time < source_frame_count - 1:
             yield time
             time += time_step
-        yield 1.0
+        yield source_frame_count - 1
 
-    source_frame_count, bone_count = sequence_data_matrix.shape[:1]
-
-    if target_frame_count == source_frame_count:
+    if time_step == 1.0:
         # No resampling is necessary.
         return sequence_data_matrix
 
+    source_frame_count, bone_count = sequence_data_matrix.shape[:2]
+    sample_times = list(get_sample_times(source_frame_count, time_step))
+    target_frame_count = len(sample_times)
     resampled_sequence_data_matrix = np.zeros((target_frame_count, bone_count, 7), dtype=float)
-    sample_times = get_sample_times(source_frame_count, target_frame_count)
 
-    for frame_index, sample_time in enumerate(sample_times):
+    for sample_index, sample_time in enumerate(sample_times):
+        frame_index = int(sample_time)
         if sample_time % 1.0 == 0.0:
             # Sample time has no fractional part, so just copy the frame.
-            resampled_sequence_data_matrix[frame_index, :, :] = sequence_data_matrix[int(sample_time), :, :]
+            resampled_sequence_data_matrix[sample_index, :, :] = sequence_data_matrix[frame_index, :, :]
         else:
             # Sample time has a fractional part, so interpolate between two frames.
+            next_frame_index = frame_index + 1
             for bone_index in range(bone_count):
-                frame_index = int(sample_time)
                 source_frame_1_data = sequence_data_matrix[frame_index, bone_index, :]
-                source_frame_2_data = sequence_data_matrix[frame_index + 1, bone_index, :]
+                source_frame_2_data = sequence_data_matrix[next_frame_index, bone_index, :]
                 factor = sample_time - frame_index
                 q = Quaternion((source_frame_1_data[:4])).slerp(Quaternion((source_frame_2_data[:4])), factor)
                 q.normalize()
                 l = Vector(source_frame_1_data[4:]).lerp(Vector(source_frame_2_data[4:]), factor)
-                resampled_sequence_data_matrix[frame_index, bone_index, :] = q.w, q.x, q.y, q.z, l.x, l.y, l.z
+                resampled_sequence_data_matrix[sample_index, bone_index, :] = q.w, q.x, q.y, q.z, l.x, l.y, l.z
 
     return resampled_sequence_data_matrix
 
@@ -268,18 +269,16 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
                     sequence_data_matrix[frame_index, bone_index] = _calculate_fcurve_data(import_bone, key_data)
 
             # Resample the sequence data to the target FPS.
-            # TODO: target frame count can be fractional.
-            target_frame_count = math.ceil(sequence.frame_count * (target_fps / sequence.fps))
+            # If the target frame count is the same as the source frame count, this will be a no-op.
+            resampled_sequence_data_matrix = _resample_sequence_data_matrix(sequence_data_matrix,
+                                                                            time_step=sequence.fps / target_fps)
 
             # Write the keyframes out.
             # Note that the f-curve data consists of alternating time and value data.
+            target_frame_count = resampled_sequence_data_matrix.shape[0]
             fcurve_data = np.zeros(2 * target_frame_count, dtype=float)
             fcurve_data[0::2] = range(0, target_frame_count)
 
-            # Resample the sequence data matrix to the target frame count.
-            # If the target frame count is the same as the source frame count, this will be a no-op.
-            resampled_sequence_data_matrix = _resample_sequence_data_matrix(sequence_data_matrix, target_frame_count)
-
             for bone_index, import_bone in enumerate(import_bones):
                 if import_bone is None:
                     continue

From 4d41f1af834d2f49953419379ad759b3ef9345eb Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Fri, 1 Mar 2024 15:14:37 -0800
Subject: [PATCH 23/31] When exporting PSKs, armatures with no bones are now
 more sensibly handled

umodel, for some reason, exports some models with no bones. For
compatibility and convenience, an armature with no bones may as well not
exist, so we treat it as though it doesn't on export, and a single fake
root bone is added for maximum compatibility.
---
 io_scene_psk_psa/psk/builder.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 4ab52d5..05d1654 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -76,9 +76,9 @@ def build_psk(context, options: PskBuildOptions) -> PskBuildResult:
     psk = Psk()
     bones = []
 
-    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.
+    if armature_object is None or len(armature_object.data.bones) == 0:
+        # If the mesh has no armature object or no bones, simply assign it a dummy bone at the root to satisfy the
+        # requirement that a PSK file must have at least one bone.
         psk_bone = Psk.Bone()
         psk_bone.name = bytes('root', encoding='windows-1252')
         psk_bone.flags = 0

From d81477673bf29959aa7d07d6635805e7cddec104 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 2 Mar 2024 13:15:48 -0800
Subject: [PATCH 24/31] Fixed a script reload issue

---
 io_scene_psk_psa/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index a5f5c6a..51a7a51 100644
--- a/io_scene_psk_psa/__init__.py
+++ b/io_scene_psk_psa/__init__.py
@@ -36,6 +36,7 @@ if 'bpy' in locals():
     importlib.reload(psa_reader)
     importlib.reload(psa_writer)
     importlib.reload(psa_builder)
+    importlib.reload(psa_importer)
     importlib.reload(psa_export_properties)
     importlib.reload(psa_export_operators)
     importlib.reload(psa_export_ui)

From 226e403925875dc6012332473662240a1e097d68 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Mon, 11 Mar 2024 18:46:18 -0700
Subject: [PATCH 25/31] Fix for syntax error

---
 io_scene_psk_psa/psa/import_/operators.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index c588208..71790c5 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -254,7 +254,7 @@ class PSA_OT_import(Operator, ImportHelper):
 
 
 class PSA_FH_import(FileHandler):
-
+    pass
 
 
 classes = (

From e27b0788666323e3a7133a28c550a3eea86492b6 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 18:53:53 -0700
Subject: [PATCH 26/31] Now handling PSKX files in the PSK file handler

---
 io_scene_psk_psa/psk/import_/operators.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psk/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index 3cebfa4..8d9dad2 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -15,7 +15,7 @@ class PSK_FH_import(FileHandler):
     bl_idname = 'PSK_FH_import'
     bl_label = 'File handler for Unreal PSK/PSKX import'
     bl_import_operator = 'import_scene.psk'
-    bl_file_extensions = '.psk'
+    bl_file_extensions = '.psk;.pskx'
 
     @classmethod
     def poll_drop(cls, context: Context):

From 6b8088225a1d83339e05c6699d9249191e85a66d Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 18:55:28 -0700
Subject: [PATCH 27/31] Fix for root bone being incorrectly oriented if it
 wasn't at the identity rotation in the bind pose

---
 io_scene_psk_psa/psa/importer.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index aad193f..1a7ea18 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -199,7 +199,8 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             import_bone.original_rotation.conjugate()
         else:
             import_bone.original_location = armature_bone.matrix_local.translation.copy()
-            import_bone.original_rotation = armature_bone.matrix_local.to_quaternion()
+            import_bone.original_rotation = armature_bone.matrix_local.to_quaternion().conjugated()
+
         import_bone.post_rotation = import_bone.original_rotation.conjugated()
 
     context.window_manager.progress_begin(0, len(sequences))

From c65fdaa6a437faafa5150e60431b4b41b0ef4477 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 19:04:12 -0700
Subject: [PATCH 28/31] Fixing PEP warnings

---
 io_scene_psk_psa/psa/config.py            |  6 +++---
 io_scene_psk_psa/psa/export/ui.py         |  2 --
 io_scene_psk_psa/psa/importer.py          |  4 ++--
 io_scene_psk_psa/psa/reader.py            | 12 ++++++------
 io_scene_psk_psa/psk/export/properties.py |  3 ++-
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/io_scene_psk_psa/psa/config.py b/io_scene_psk_psa/psa/config.py
index 3016c59..66864e4 100644
--- a/io_scene_psk_psa/psa/config.py
+++ b/io_scene_psk_psa/psa/config.py
@@ -14,7 +14,7 @@ class PsaConfig:
 
 
 def _load_config_file(file_path: str) -> ConfigParser:
-    '''
+    """
     UEViewer exports a dialect of INI files that is not compatible with Python's ConfigParser.
     Specifically, it allows values in this format:
 
@@ -24,7 +24,7 @@ def _load_config_file(file_path: str) -> ConfigParser:
 
     This is not allowed in Python's ConfigParser, which requires a '=' character after each key name.
     To work around this, we'll modify the file to add the '=' character after each key name if it is missing.
-    '''
+    """
     with open(file_path, 'r') as f:
         lines = f.read().split('\n')
 
@@ -41,7 +41,7 @@ def _load_config_file(file_path: str) -> ConfigParser:
 def _get_bone_flags_from_value(value: str) -> int:
     match value:
         case 'all':
-            return (REMOVE_TRACK_LOCATION | REMOVE_TRACK_ROTATION)
+            return REMOVE_TRACK_LOCATION | REMOVE_TRACK_ROTATION
         case 'trans':
             return REMOVE_TRACK_LOCATION
         case 'rot':
diff --git a/io_scene_psk_psa/psa/export/ui.py b/io_scene_psk_psa/psa/export/ui.py
index 203b530..1c92337 100644
--- a/io_scene_psk_psa/psa/export/ui.py
+++ b/io_scene_psk_psa/psa/export/ui.py
@@ -32,7 +32,6 @@ class PSA_UL_export_sequences(UIList):
         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_sort_reverse', text='', icon='SORT_ASC')
 
         if pg.sequence_source == 'ACTIONS':
             subrow = row.row(align=True)
@@ -44,7 +43,6 @@ class PSA_UL_export_sequences(UIList):
         pg = getattr(context.scene, 'psa_export')
         actions = getattr(data, prop)
         flt_flags = filter_sequences(pg, actions)
-        # flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(actions, 'name')
         flt_neworder = list(range(len(actions)))
         return flt_flags, flt_neworder
 
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 1a7ea18..cedef80 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -64,12 +64,12 @@ class PsaImportResult:
 
 
 def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_names: List[str], bone_mapping_mode: str = 'EXACT') -> Optional[int]:
-    '''
+    """
     @param psa_bone_name: The name of the PSA bone.
     @param armature_bone_names: The names of the bones in the armature.
     @param bone_mapping_mode: One of 'EXACT' or 'CASE_INSENSITIVE'.
     @return: The index of the armature bone that corresponds to the given PSA bone, or None if no such bone exists.
-    '''
+    """
     for armature_bone_index, armature_bone_name in enumerate(armature_bone_names):
         if bone_mapping_mode == 'CASE_INSENSITIVE':
             if armature_bone_name.lower() == psa_bone_name.lower():
diff --git a/io_scene_psk_psa/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index 08060b9..bd12dc7 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -23,11 +23,11 @@ def _try_fix_cue4parse_issue_103(sequences) -> bool:
 
 
 class PsaReader(object):
-    '''
+    """
     This class reads the sequences and bone information immediately upon instantiation and holds onto a file handle.
     The keyframe data is not read into memory upon instantiation due to its 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
@@ -43,11 +43,11 @@ class PsaReader(object):
         return self.psa.sequences
 
     def read_sequence_data_matrix(self, sequence_name: str) -> np.ndarray:
-        '''
+        """
         Reads and returns the data matrix for the given sequence.
         @param sequence_name: The name of the sequence.
         @return: An FxBx7 matrix where F is the number of frames, B is the number of bones.
-        '''
+        """
         sequence = self.psa.sequences[sequence_name]
         keys = self.read_sequence_keys(sequence_name)
         bone_count = len(self.bones)
@@ -60,12 +60,12 @@ class PsaReader(object):
         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)
diff --git a/io_scene_psk_psa/psk/export/properties.py b/io_scene_psk_psa/psk/export/properties.py
index bdb6493..536ca62 100644
--- a/io_scene_psk_psa/psk/export/properties.py
+++ b/io_scene_psk_psa/psk/export/properties.py
@@ -3,6 +3,7 @@ from bpy.types import PropertyGroup, Material
 
 from ...types import PSX_PG_bone_collection_list_item
 
+empty_set = set()
 
 class PSK_PG_material_list_item(PropertyGroup):
     material: PointerProperty(type=Material)
@@ -12,7 +13,7 @@ class PSK_PG_material_list_item(PropertyGroup):
 class PSK_PG_export(PropertyGroup):
     bone_filter_mode: EnumProperty(
         name='Bone Filter',
-        options=set(),
+        options=empty_set,
         description='',
         items=(
             ('ALL', 'All', 'All bones will be exported'),

From a93450eab92c8dab221f14dec6c9f0113aac0ca2 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 19:06:03 -0700
Subject: [PATCH 29/31] Added PSA file handler

---
 io_scene_psk_psa/psa/import_/operators.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index 71790c5..dbdff50 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -254,7 +254,14 @@ class PSA_OT_import(Operator, ImportHelper):
 
 
 class PSA_FH_import(FileHandler):
-    pass
+    bl_idname = 'PSA_FH_import'
+    bl_label = 'File handler for Unreal PSA import'
+    bl_import_operator = 'psa_import.import'
+    bl_file_extensions = '.psa'
+
+    @classmethod
+    def poll_drop(cls, context: Context):
+        return context.area and context.area.type == 'VIEW_3D'
 
 
 classes = (
@@ -262,4 +269,5 @@ classes = (
     PSA_OT_import_sequences_deselect_all,
     PSA_OT_import_sequences_from_text,
     PSA_OT_import,
+    PSA_FH_import,
 )

From d4d46bea661de6a1c00e439c4d2b064eabbb0653 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 19:06:29 -0700
Subject: [PATCH 30/31] PSA import dialog now uses new Blender 4.1 UI panels

---
 io_scene_psk_psa/psa/import_/operators.py | 100 +++++++++++-----------
 1 file changed, 52 insertions(+), 48 deletions(-)

diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index dbdff50..0dd98c9 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -190,67 +190,71 @@ class PSA_OT_import(Operator, ImportHelper):
         layout = self.layout
         pg = getattr(context.scene, 'psa_import')
 
-        if pg.psa_error:
-            row = layout.row()
-            row.label(text='Select a PSA file', icon='ERROR')
-        else:
-            box = layout.box()
+        sequences_header, sequences_panel = layout.panel('sequences_panel_id', default_closed=False)
+        sequences_header.label(text='Sequences')
 
-            box.label(text=f'Sequences ({len(pg.sequence_list)})', icon='ARMATURE_DATA')
+        if sequences_panel:
+            if pg.psa_error:
+                row = sequences_panel.row()
+                row.label(text='Select a PSA file', icon='ERROR')
+            else:
+                # Select buttons.
+                rows = max(3, min(len(pg.sequence_list), 10))
 
-            # Select buttons.
-            rows = max(3, min(len(pg.sequence_list), 10))
+                row = sequences_panel.row()
+                col = row.column()
 
-            row = box.row()
-            col = row.column()
+                row2 = col.row(align=True)
+                row2.label(text='Select')
+                row2.operator(PSA_OT_import_sequences_from_text.bl_idname, text='', icon='TEXT')
+                row2.operator(PSA_OT_import_sequences_select_all.bl_idname, text='All', icon='CHECKBOX_HLT')
+                row2.operator(PSA_OT_import_sequences_deselect_all.bl_idname, text='None', icon='CHECKBOX_DEHLT')
 
-            row2 = col.row(align=True)
-            row2.label(text='Select')
-            row2.operator(PSA_OT_import_sequences_from_text.bl_idname, text='', icon='TEXT')
-            row2.operator(PSA_OT_import_sequences_select_all.bl_idname, text='All', icon='CHECKBOX_HLT')
-            row2.operator(PSA_OT_import_sequences_deselect_all.bl_idname, text='None', icon='CHECKBOX_DEHLT')
+                col = col.row()
+                col.template_list('PSA_UL_import_sequences', '', pg, 'sequence_list', pg, 'sequence_list_index', rows=rows)
 
-            col = col.row()
-            col.template_list('PSA_UL_import_sequences', '', 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')
-
-        col = layout.column()
-        col.use_property_split = True
-        col.use_property_decorate = False
-        col.prop(pg, 'bone_mapping_mode')
-
-        if pg.should_write_keyframes:
-            col = layout.column(heading='Keyframes')
+            col = sequences_panel.column(heading='')
             col.use_property_split = True
             col.use_property_decorate = False
-            col.prop(pg, 'should_convert_to_samples')
-            col.separator()
-            # FPS
             col.prop(pg, 'fps_source')
             if pg.fps_source == 'CUSTOM':
                 col.prop(pg, 'fps_custom')
+            col.prop(pg, 'should_overwrite')
+            col.prop(pg, 'should_use_action_name_prefix')
+            if pg.should_use_action_name_prefix:
+                col.prop(pg, 'action_name_prefix')
 
-        col = layout.column(heading='Options')
-        col.use_property_split = True
-        col.use_property_decorate = False
-        col.prop(pg, 'should_use_fake_user')
-        col.prop(pg, 'should_stash')
-        col.prop(pg, 'should_use_config_file')
+        data_header, data_panel = layout.panel('data_panel_id', default_closed=False)
+        data_header.label(text='Data')
 
-        col.prop(pg, 'should_use_action_name_prefix')
+        if data_panel:
+            col = data_panel.column(heading='Write')
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(pg, 'should_write_keyframes')
+            col.prop(pg, 'should_write_metadata')
 
-        if pg.should_use_action_name_prefix:
-            col.prop(pg, 'action_name_prefix')
+            if pg.should_write_keyframes:
+                col = col.column(heading='Keyframes')
+                col.use_property_split = True
+                col.use_property_decorate = False
+                col.prop(pg, 'should_convert_to_samples')
+
+        advanced_header, advanced_panel = layout.panel('advanced_panel_id', default_closed=True)
+        advanced_header.label(text='Advanced')
+
+        if advanced_panel:
+            col = advanced_panel.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(pg, 'bone_mapping_mode')
+
+            col = advanced_panel.column(heading='Options')
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(pg, 'should_use_fake_user')
+            col.prop(pg, 'should_stash')
+            col.prop(pg, 'should_use_config_file')
 
 
 class PSA_FH_import(FileHandler):

From fb0274238105067dfeb6029219293cd75ab8c725 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Thu, 14 Mar 2024 19:08:32 -0700
Subject: [PATCH 31/31] Reorganizing & renaming some things for clarity and
 correctness

---
 io_scene_psk_psa/psa/import_/properties.py |  6 +--
 io_scene_psk_psa/psa/importer.py           | 57 +++++++++++-----------
 2 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/io_scene_psk_psa/psa/import_/properties.py b/io_scene_psk_psa/psa/import_/properties.py
index 43dd375..0664eb8 100644
--- a/io_scene_psk_psa/psa/import_/properties.py
+++ b/io_scene_psk_psa/psa/import_/properties.py
@@ -75,13 +75,13 @@ class PSA_PG_import(PropertyGroup):
     )
     fps_source: EnumProperty(name='FPS Source', items=(
         ('SEQUENCE', 'Sequence', 'The sequence frame rate matches the original frame rate', 'ACTION', 0),
-        ('SCENE', 'Scene', 'The sequence frame rate dilates to match that of the scene', 'SCENE_DATA', 1),
-        ('CUSTOM', 'Custom', 'The sequence frame rate dilates to match a custom frame rate', 2),
+        ('SCENE', 'Scene', 'The sequence is resampled to the frame rate of the scene', 'SCENE_DATA', 1),
+        ('CUSTOM', 'Custom', 'The sequence is resampled to a custom frame rate', 2),
     ))
     fps_custom: FloatProperty(
         default=30.0,
         name='Custom FPS',
-        description='The frame rate to which the imported actions will be converted',
+        description='The frame rate to which the imported sequences will be resampled to',
         options=empty_set,
         min=1.0,
         soft_min=1.0,
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index cedef80..c307413 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -46,16 +46,16 @@ def _calculate_fcurve_data(import_bone: ImportBone, key_data: typing.Iterable[fl
     key_location = Vector(key_data[4:])
     q = import_bone.post_rotation.copy()
     q.rotate(import_bone.original_rotation)
-    quat = q
+    rotation = q
     q = import_bone.post_rotation.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.original_location
-    loc.rotate(import_bone.post_rotation.conjugated())
-    return quat.w, quat.x, quat.y, quat.z, loc.x, loc.y, loc.z
+    rotation.rotate(q.conjugated())
+    location = key_location - import_bone.original_location
+    location.rotate(import_bone.post_rotation.conjugated())
+    return rotation.w, rotation.x, rotation.y, rotation.z, location.x, location.y, location.z
 
 
 class PsaImportResult:
@@ -79,49 +79,48 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
                 return armature_bone_index
     return None
 
+def _get_sample_frame_times(source_frame_count: int, frame_step: float) -> typing.Iterable[float]:
+    # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
+    #  fractional frame).
+    time = 0.0
+    while time < source_frame_count - 1:
+        yield time
+        time += frame_step
+    yield source_frame_count - 1
 
-def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, time_step: float = 1.0) -> np.ndarray:
-    '''
+def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, frame_step: float = 1.0) -> np.ndarray:
+    """
     Resamples the sequence data matrix to the target frame count.
     @param sequence_data_matrix: FxBx7 matrix where F is the number of frames, B is the number of bones, and X is the
     number of data elements per bone.
-    @param target_frame_count: The number of frames to resample to.
+    @param frame_step: The step between frames in the resampled sequence.
     @return: The resampled sequence data matrix, or sequence_data_matrix if no resampling is necessary.
-    '''
-    def get_sample_times(source_frame_count: int, time_step: float) -> typing.Iterable[float]:
-        # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
-        #  fractional frame).
-        time = 0.0
-        while time < source_frame_count - 1:
-            yield time
-            time += time_step
-        yield source_frame_count - 1
-
-    if time_step == 1.0:
+    """
+    if frame_step == 1.0:
         # No resampling is necessary.
         return sequence_data_matrix
 
     source_frame_count, bone_count = sequence_data_matrix.shape[:2]
-    sample_times = list(get_sample_times(source_frame_count, time_step))
-    target_frame_count = len(sample_times)
+    sample_frame_times = list(_get_sample_frame_times(source_frame_count, frame_step))
+    target_frame_count = len(sample_frame_times)
     resampled_sequence_data_matrix = np.zeros((target_frame_count, bone_count, 7), dtype=float)
 
-    for sample_index, sample_time in enumerate(sample_times):
-        frame_index = int(sample_time)
-        if sample_time % 1.0 == 0.0:
+    for sample_frame_index, sample_frame_time in enumerate(sample_frame_times):
+        frame_index = int(sample_frame_time)
+        if sample_frame_time % 1.0 == 0.0:
             # Sample time has no fractional part, so just copy the frame.
-            resampled_sequence_data_matrix[sample_index, :, :] = sequence_data_matrix[frame_index, :, :]
+            resampled_sequence_data_matrix[sample_frame_index, :, :] = sequence_data_matrix[frame_index, :, :]
         else:
             # Sample time has a fractional part, so interpolate between two frames.
             next_frame_index = frame_index + 1
             for bone_index in range(bone_count):
                 source_frame_1_data = sequence_data_matrix[frame_index, bone_index, :]
                 source_frame_2_data = sequence_data_matrix[next_frame_index, bone_index, :]
-                factor = sample_time - frame_index
+                factor = sample_frame_time - frame_index
                 q = Quaternion((source_frame_1_data[:4])).slerp(Quaternion((source_frame_2_data[:4])), factor)
                 q.normalize()
                 l = Vector(source_frame_1_data[4:]).lerp(Vector(source_frame_2_data[4:]), factor)
-                resampled_sequence_data_matrix[sample_index, bone_index, :] = q.w, q.x, q.y, q.z, l.x, l.y, l.z
+                resampled_sequence_data_matrix[sample_frame_index, bone_index, :] = q.w, q.x, q.y, q.z, l.x, l.y, l.z
 
     return resampled_sequence_data_matrix
 
@@ -188,8 +187,10 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
 
     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 import_bone.parent is not None:
             import_bone.original_location = armature_bone.matrix_local.translation - armature_bone.parent.matrix_local.translation
@@ -272,7 +273,7 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             # Resample the sequence data to the target FPS.
             # If the target frame count is the same as the source frame count, this will be a no-op.
             resampled_sequence_data_matrix = _resample_sequence_data_matrix(sequence_data_matrix,
-                                                                            time_step=sequence.fps / target_fps)
+                                                                            frame_step=sequence.fps / target_fps)
 
             # Write the keyframes out.
             # Note that the f-curve data consists of alternating time and value data.