From 0c11b326afb70444aa610b036e10a3626a8cae9e Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Tue, 16 Jan 2024 20:21:12 -0800
Subject: [PATCH 01/19] Update README.md

---
 README.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/README.md b/README.md
index 99782e2..a60f3f0 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,12 @@ Bug fixes will be issued for legacy addon versions that are under [Blender's LTS
 > Note that in order to see the imported actions applied to your armature, you must use the [Dope Sheet](https://docs.blender.org/manual/en/latest/editors/dope_sheet/introduction.html) or [Nonlinear Animation](https://docs.blender.org/manual/en/latest/editors/nla/introduction.html) editors.
 
 # FAQ
+
+## Why can't I see the animations imported from my PSA?
+Simply importing an animation into the scene will not automatically apply the action to the armature. This is in part because a PSA can have multiple sequences imported from it, and also that it's generally bad form for importers to modify the scene when they don't need to.
+
+The PSA importer creates [Actions](https://docs.blender.org/manual/en/latest/animation/actions.html) for each of the selected sequences in the PSA. These actions can be applied to your armature via the [Action Editor](https://docs.blender.org/manual/en/latest/editors/dope_sheet/action.html) or [NLA Editor](https://docs.blender.org/manual/en/latest/editors/nla/index.html).
+
 ## Why are the mesh normals not accurate when importing a PSK extracted from [UE Viewer](https://www.gildor.org/en/projects/umodel)?
 If preserving the mesh normals of models is important for your workflow, it is *not recommended* to export PSK files from UE Viewer. This is because UE Viewer makes no attempt to reconstruct the original [smoothing groups](https://en.wikipedia.org/wiki/Smoothing_group). As a result, the normals of imported PSK files will be incorrect when imported into Blender and will need to be manually fixed.
 

From 82310d695ce9beb3e07beec180dfa17a9369ad49 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 20 Jan 2024 15:25:00 -0800
Subject: [PATCH 02/19] Fix for parsing errors on .config files coming from
 UEViewer

---
 io_scene_psk_psa/psa/config.py             | 58 ++++++++++++++++------
 io_scene_psk_psa/psa/import_/operators.py  | 22 +++++---
 io_scene_psk_psa/psa/import_/properties.py |  6 +++
 io_scene_psk_psa/psa/importer.py           |  1 +
 4 files changed, 65 insertions(+), 22 deletions(-)

diff --git a/io_scene_psk_psa/psa/config.py b/io_scene_psk_psa/psa/config.py
index f9e1515..184d59c 100644
--- a/io_scene_psk_psa/psa/config.py
+++ b/io_scene_psk_psa/psa/config.py
@@ -13,36 +13,66 @@ class PsaConfig:
         self.sequence_bone_flags: Dict[str, Dict[int, int]] = dict()
 
 
+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:
+
+    [Section]
+    Key1
+    Key2
+
+    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')
+
+    lines = [re.sub(r'^\s*(\w+)\s*$', r'\1=', line) for line in lines]
+
+    contents = '\n'.join(lines)
+
+    config = ConfigParser()
+    config.read_string(contents)
+
+    return config
+
+
+def _get_bone_flags_from_value(value: str) -> int:
+    match value:
+        case 'all':
+            return (REMOVE_TRACK_LOCATION | REMOVE_TRACK_ROTATION)
+        case 'trans':
+            return REMOVE_TRACK_LOCATION
+        case 'rot':
+            return REMOVE_TRACK_ROTATION
+        case _:
+            return 0
+
+
 def read_psa_config(psa_reader: PsaReader, file_path: str) -> PsaConfig:
     psa_config = PsaConfig()
 
-    config = ConfigParser()
-    config.read(file_path)
-
-    psa_sequence_names = list(psa_reader.sequences.keys())
-    lowercase_sequence_names = [sequence_name.lower() for sequence_name in psa_sequence_names]
+    config = _load_config_file(file_path)
 
     if config.has_section('RemoveTracks'):
         for key, value in config.items('RemoveTracks'):
             match = re.match(f'^(.+)\.(\d+)$', key)
             sequence_name = match.group(1)
-            bone_index = int(match.group(2))
 
             # Map the sequence name onto the actual sequence name in the PSA file.
             try:
+                psa_sequence_names = list(psa_reader.sequences.keys())
+                lowercase_sequence_names = [sequence_name.lower() for sequence_name in psa_sequence_names]
                 sequence_name = psa_sequence_names[lowercase_sequence_names.index(sequence_name.lower())]
             except ValueError:
-                pass
+                # Sequence name is not in the PSA file.
+                continue
 
             if sequence_name not in psa_config.sequence_bone_flags:
                 psa_config.sequence_bone_flags[sequence_name] = dict()
 
-            match value:
-                case 'all':
-                    psa_config.sequence_bone_flags[sequence_name][bone_index] = (REMOVE_TRACK_LOCATION | REMOVE_TRACK_ROTATION)
-                case 'trans':
-                    psa_config.sequence_bone_flags[sequence_name][bone_index] = REMOVE_TRACK_LOCATION
-                case 'rot':
-                    psa_config.sequence_bone_flags[sequence_name][bone_index] = REMOVE_TRACK_ROTATION
+            bone_index = int(match.group(2))
+            psa_config.sequence_bone_flags[sequence_name][bone_index] = _get_bone_flags_from_value(value)
 
     return psa_config
diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index afa964d..4b75a1a 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -158,6 +158,10 @@ class PSA_OT_import(Operator, ImportHelper):
         psa_reader = PsaReader(self.filepath)
         sequence_names = [x.action_name for x in pg.sequence_list if x.is_selected]
 
+        if len(sequence_names) == 0:
+            self.report({'ERROR_INVALID_CONTEXT'}, 'No sequences selected')
+            return {'CANCELLED'}
+
         options = PsaImportOptions()
         options.sequence_names = sequence_names
         options.should_use_fake_user = pg.should_use_fake_user
@@ -171,14 +175,14 @@ class PSA_OT_import(Operator, ImportHelper):
         options.fps_source = pg.fps_source
         options.fps_custom = pg.fps_custom
 
-        # Read the PSA config file if it exists.
-        config_path = Path(self.filepath).with_suffix('.config')
-        if config_path.exists():
-            options.psa_config = read_psa_config(psa_reader, str(config_path))
-
-        if len(sequence_names) == 0:
-            self.report({'ERROR_INVALID_CONTEXT'}, 'No sequences selected')
-            return {'CANCELLED'}
+        if options.should_use_config_file:
+            # Read the PSA config file if it exists.
+            config_path = Path(self.filepath).with_suffix('.config')
+            if config_path.exists():
+                try:
+                    options.psa_config = read_psa_config(psa_reader, str(config_path))
+                except Exception as e:
+                    self.report({'WARNING'}, f'Failed to read PSA config file: {e}')
 
         result = import_psa(context, psa_reader, context.view_layer.objects.active, options)
 
@@ -258,6 +262,8 @@ class PSA_OT_import(Operator, ImportHelper):
         col.use_property_decorate = False
         col.prop(pg, 'should_use_fake_user')
         col.prop(pg, 'should_stash')
+        col.prop(pg, 'should_use_config_file')
+
         col.prop(pg, 'should_use_action_name_prefix')
 
         if pg.should_use_action_name_prefix:
diff --git a/io_scene_psk_psa/psa/import_/properties.py b/io_scene_psk_psa/psa/import_/properties.py
index b7e14f5..43dd375 100644
--- a/io_scene_psk_psa/psa/import_/properties.py
+++ b/io_scene_psk_psa/psa/import_/properties.py
@@ -32,6 +32,12 @@ class PSA_PG_import(PropertyGroup):
                                        description='Assign each imported action a fake user so that the data block is '
                                                    'saved even it has no users',
                                        options=empty_set)
+    should_use_config_file: BoolProperty(default=True, name='Use Config File',
+                                            description='Use the .config file that is sometimes generated when the PSA '
+                                                        'file is exported from UEViewer. This file contains '
+                                                        'options that can be used to filter out certain bones tracks '
+                                                        'from the imported actions',
+                                            options=empty_set)
     should_stash: BoolProperty(default=False, name='Stash',
                                description='Stash each imported action as a strip on a new non-contributing NLA track',
                                options=empty_set)
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index c4a66cc..5864645 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -24,6 +24,7 @@ class PsaImportOptions(object):
         self.bone_mapping_mode = 'CASE_INSENSITIVE'
         self.fps_source = 'SEQUENCE'
         self.fps_custom: float = 30.0
+        self.should_use_config_file = True
         self.psa_config: PsaConfig = PsaConfig()
 
 

From d0f64a6546dccec8035d97f981edf09ab98249c8 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 20 Jan 2024 15:25:14 -0800
Subject: [PATCH 03/19] Incremented version to 6.1.1

---
 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 9f12fa4..aa72ddc 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, 0),
+    "version": (6, 1, 1),
     "blender": (4, 0, 0),
     "description": "PSK/PSA Import/Export (.psk/.psa)",
     "warning": "",

From b4712295847fabb0ca3e989cfe7236add6e43dae Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 20 Jan 2024 15:25:48 -0800
Subject: [PATCH 04/19] Rephrased description of PSA export option

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

diff --git a/io_scene_psk_psa/psa/export/properties.py b/io_scene_psk_psa/psa/export/properties.py
index 518adf9..59cd755 100644
--- a/io_scene_psk_psa/psa/export/properties.py
+++ b/io_scene_psk_psa/psa/export/properties.py
@@ -152,7 +152,7 @@ class PSA_PG_export(PropertyGroup):
         default=False,
         name='Enforce Bone Name Restrictions',
         description='Bone names restrictions will be enforced. Note that bone names without properly formatted names '
-                    'cannot be referenced in scripts'
+                    'may not be able to be referenced in-engine'
     )
     sequence_name_prefix: StringProperty(name='Prefix', options=empty_set)
     sequence_name_suffix: StringProperty(name='Suffix', options=empty_set)

From 361a7f021859695b30ed2baeda47bbe994e6f4a2 Mon Sep 17 00:00:00 2001
From: Colin Basnett <cmbasnett@gmail.com>
Date: Sat, 20 Jan 2024 15:31:26 -0800
Subject: [PATCH 05/19] Added the name of the imported PSK object to the info
 report

---
 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 1cabb22..e90b44c 100644
--- a/io_scene_psk_psa/psk/import_/operators.py
+++ b/io_scene_psk_psa/psk/import_/operators.py
@@ -113,7 +113,7 @@ class PSK_OT_import(Operator, ImportHelper):
             message += '\n'.join(result.warnings)
             self.report({'WARNING'}, message)
         else:
-            self.report({'INFO'}, f'PSK imported')
+            self.report({'INFO'}, f'PSK imported ({options.name})')
 
         return {'FINISHED'}
 

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 06/19] 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 07/19] 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 08/19] 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 09/19] 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 10/19] 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 11/19] 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 12/19] 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 13/19] 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 14/19] 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 15/19] 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 16/19] 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 17/19] 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 18/19] 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 19/19] 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