diff --git a/io_scene_psk_psa/__init__.py b/io_scene_psk_psa/__init__.py
index aa72ddc..51a7a51 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, 1),
-    "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, 2, 0),
+    '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():
@@ -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)
@@ -34,6 +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)
@@ -50,6 +53,8 @@ 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 +77,8 @@ 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 +114,7 @@ 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 +122,7 @@ 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/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..66864e4 100644
--- a/io_scene_psk_psa/psa/config.py
+++ b/io_scene_psk_psa/psa/config.py
@@ -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/data.py b/io_scene_psk_psa/psa/data.py
index 89bc159..f6532d5 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/operators.py b/io_scene_psk_psa/psa/export/operators.py
index 115451f..cfb11ee 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)
@@ -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:
@@ -110,7 +111,7 @@ 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
diff --git a/io_scene_psk_psa/psa/export/ui.py b/io_scene_psk_psa/psa/export/ui.py
index d302265..1c92337 100644
--- a/io_scene_psk_psa/psa/export/ui.py
+++ b/io_scene_psk_psa/psa/export/ui.py
@@ -30,21 +30,19 @@ 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_use_filter_sort_reverse', text='', icon='SORT_ASC')
+        subrow.prop(pg, 'sequence_filter_name', text='')
+        subrow.prop(pg, 'sequence_use_filter_invert', text='', icon='ARROW_LEFTRIGHT')
 
         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')
         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/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index a5df890..fd96e6f 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()
@@ -208,69 +191,83 @@ 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')
-            # Scale Keys
+            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')
+
+        data_header, data_panel = layout.panel('data_panel_id', default_closed=False)
+        data_header.label(text='Data')
+
+        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')
             col.prop(pg, 'should_write_scale_keys')
 
-        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')
+            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')
 
-        col.prop(pg, 'should_use_action_name_prefix')
+        advanced_header, advanced_panel = layout.panel('advanced_panel_id', default_closed=True)
+        advanced_header.label(text='Advanced')
 
-        if pg.should_use_action_name_prefix:
-            col.prop(pg, 'action_name_prefix')
+        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):
+    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 = (
@@ -278,5 +275,5 @@ classes = (
     PSA_OT_import_sequences_deselect_all,
     PSA_OT_import_sequences_from_text,
     PSA_OT_import,
-    PSA_OT_import_select_file,
+    PSA_FH_import,
 )
diff --git a/io_scene_psk_psa/psa/import_/properties.py b/io_scene_psk_psa/psa/import_/properties.py
index b571c60..884c4da 100644
--- a/io_scene_psk_psa/psa/import_/properties.py
+++ b/io_scene_psk_psa/psa/import_/properties.py
@@ -77,13 +77,13 @@ 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/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 094441c..2f9f749 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -2,7 +2,7 @@ import typing
 from typing import List, Optional, Iterable
 
 import bpy
-import numpy
+import numpy as np
 from bpy.types import FCurve, Object, Context
 from mathutils import Vector, Quaternion
 
@@ -48,16 +48,16 @@ def _calculate_fcurve_data(import_bone: ImportBone, key_data: Iterable[float]):
     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:
@@ -81,6 +81,51 @@ def _get_armature_bone_index_for_psa_bone(psa_bone_name: str, armature_bone_name
                 return armature_bone_index
     return None
 
+def _get_sample_frame_times(source_frame_count: int, frame_step: float) -> typing.Iterable[float]:
+    # TODO: for correctness, we should also emit the target frame time as well (because the last frame can be a
+    #  fractional frame).
+    time = 0.0
+    while time < source_frame_count - 1:
+        yield time
+        time += frame_step
+    yield source_frame_count - 1
+
+def _resample_sequence_data_matrix(sequence_data_matrix: np.ndarray, frame_step: float = 1.0) -> np.ndarray:
+    """
+    Resamples the sequence data matrix to the target frame count.
+    @param sequence_data_matrix: FxBx7 matrix where F is the number of frames, B is the number of bones, and X is the
+    number of data elements per bone.
+    @param frame_step: The step between frames in the resampled sequence.
+    @return: The resampled sequence data matrix, or sequence_data_matrix if no resampling is necessary.
+    """
+    if frame_step == 1.0:
+        # No resampling is necessary.
+        return sequence_data_matrix
+
+    source_frame_count, bone_count = sequence_data_matrix.shape[:2]
+    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_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_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_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_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()
@@ -144,8 +189,10 @@ 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
@@ -155,7 +202,8 @@ 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))
@@ -178,21 +226,19 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
             action = bpy.data.actions.new(name=action_name)
 
         # Calculate the target 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}')
-
-        keyframe_time_dilation = target_fps / sequence.fps
+        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}')
 
         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():
@@ -234,19 +280,25 @@ 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.
+            # 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,
+                                                                            frame_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)
 
-            # 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/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index b7aaffc..d19d5b0 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -12,15 +12,14 @@ 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
 
 
diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 623ae66..05d1654 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -1,15 +1,19 @@
+from typing import Optional
+
 import bmesh
 import bpy
-from bpy.types import Armature
+import numpy as np
+from bpy.types import Armature, Material
 
 from .data import *
+from .properties import triangle_type_and_bit_flags_to_poly_flags
 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):
@@ -17,7 +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
 
 
@@ -61,7 +65,7 @@ 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:
@@ -72,9 +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
@@ -135,21 +139,25 @@ 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 = 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))
 
+    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
+
         # MATERIALS
         material_indices = [material_names.index(material_slot.material.name) for material_slot in input_mesh_object.material_slots]
 
@@ -177,8 +185,16 @@ 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:
@@ -207,11 +223,11 @@ 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:
@@ -219,8 +235,8 @@ 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:
@@ -233,6 +249,7 @@ 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 +259,11 @@ 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)
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/export/operators.py b/io_scene_psk_psa/psk/export/operators.py
index 80e097f..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
 
 
@@ -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):
@@ -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..536ca62 100644
--- a/io_scene_psk_psa/psk/export/properties.py
+++ b/io_scene_psk_psa/psk/export/properties.py
@@ -1,18 +1,19 @@
-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
 
+empty_set = set()
 
 class PSK_PG_material_list_item(PropertyGroup):
-    material_name: StringProperty()
+    material: PointerProperty(type=Material)
     index: IntProperty()
 
 
 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'),
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/import_/operators.py b/io_scene_psk_psa/psk/import_/operators.py
index e90b44c..8d9dad2 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 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'
+
+    @classmethod
+    def poll_drop(cls, context: Context):
+        return context.area and context.area.type == 'VIEW_3D'
+
+
 class PSK_OT_import(Operator, ImportHelper):
     bl_idname = 'import_scene.psk'
     bl_label = 'Import'
@@ -27,8 +38,8 @@ 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 +53,13 @@ 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 +74,6 @@ 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',
@@ -82,14 +87,20 @@ 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(
         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)
@@ -105,6 +116,11 @@ 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
+
+        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)
 
@@ -119,26 +135,42 @@ class PSK_OT_import(Operator, ImportHelper):
 
     def draw(self, context):
         layout = self.layout
-        layout.prop(self, 'should_import_materials')
-        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, 'scale')
+
+        mesh_header, mesh_panel = layout.panel('mesh_panel_id', default_closed=False)
+        mesh_header.prop(self, 'should_import_mesh')
+
+        if mesh_panel and self.should_import_mesh:
+            row = mesh_panel.row()
+            col = row.column()
+            col.use_property_split = True
+            col.use_property_decorate = False
+            col.prop(self, 'should_import_materials', text='Materials')
+            col.prop(self, 'should_import_vertex_normals', text='Vertex Normals')
+            col.prop(self, 'should_import_extra_uvs', text='Extra UVs')
+            col.prop(self, 'should_import_vertex_colors', text='Vertex Colors')
             if self.should_import_vertex_colors:
-                row.prop(self, 'vertex_color_space')
-            row.prop(self, 'should_import_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')
+                col.prop(self, 'vertex_color_space')
+            col.prop(self, 'should_import_shape_keys', text='Shape Keys')
+
+        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
+            col.prop(self, 'bone_length')
 
 
 classes = (
     PSK_OT_import,
+    PSK_FH_import,
 )
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index f07fd11..24ea1ef 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
@@ -8,6 +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
 
 
@@ -17,19 +17,20 @@ 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
         self.should_import_shape_keys = True
         self.bone_length = 1.0
         self.should_import_materials = True
+        self.scale = 1.0
 
 
 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
@@ -52,6 +53,7 @@ class PskImportResult:
 def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
     result = PskImportResult()
     armature_object = None
+    mesh_object = None
 
     if options.should_import_skeleton:
         # ARMATURE
@@ -133,6 +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)
 
@@ -144,6 +149,7 @@ 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))
@@ -164,61 +170,59 @@ 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:
-            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 vertex_color_index in range(len(psk.vertex_colors)):
+                psk_vertex_colors[vertex_color_index,:] = psk.vertex_colors[vertex_color_index].normalized()
+            match options.vertex_color_space:
+                case 'SRGBA':
+                    for i in range(psk_vertex_colors.shape[0]):
+                        psk_vertex_colors[i, :3] = tuple(map(lambda x: rgb_to_srgb(x), psk_vertex_colors[i, :3]))
+                case _:
+                    pass
 
-            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_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
 
-            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:
@@ -267,6 +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:
diff --git a/io_scene_psk_psa/psk/properties.py b/io_scene_psk_psa/psk/properties.py
new file mode 100644
index 0000000..917f390
--- /dev/null
+++ b/io_scene_psk_psa/psk/properties.py
@@ -0,0 +1,48 @@
+from bpy.props import EnumProperty
+from bpy.types import PropertyGroup
+
+mesh_triangle_types_items = (
+    ('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 = (
+    ('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):
+    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 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.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,
+)
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)
 
 
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/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
 
 
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,
 )