diff --git a/io_scene_psk_psa/psa/builder.py b/io_scene_psk_psa/psa/builder.py
index 95bd914..e52da43 100644
--- a/io_scene_psk_psa/psa/builder.py
+++ b/io_scene_psk_psa/psa/builder.py
@@ -1,7 +1,10 @@
-from bpy.types import Action, PoseBone
+from bpy.types import Action, AnimData, Context, Object, PoseBone
 
 from .data import Psa
-from ..shared.helpers import *
+from typing import Dict, List, Optional, Tuple
+from mathutils import Matrix, Quaternion, Vector
+
+from ..shared.helpers import create_psx_bones, get_coordinate_system_transform
 
 
 class PsaBuildSequence:
@@ -62,7 +65,6 @@ def _get_pose_bone_location_and_rotation(
             # Get the bone's pose matrix and transform it into the export space.
             # In the case of an 'ARMATURE' export space, this will be the inverse of armature object's world matrix.
             # Otherwise, it will be the identity matrix.
-            # TODO: taking the pose bone matrix puts this in armature space.
             match export_space:
                 case 'ARMATURE':
                     pose_bone_matrix = pose_bone.matrix
@@ -81,7 +83,7 @@ def _get_pose_bone_location_and_rotation(
     rotation = pose_bone_matrix.to_quaternion().normalized()
 
     # TODO: this has gotten way more complicated than it needs to be.
-    # TODO: don't apply scale to the root bone of armatures if we have a false root:
+    # Don't apply scale to the root bone of armatures if we have a false root.
     if not has_false_root_bone or (pose_bone is None or pose_bone.parent is not None):
         location *= scale
 
@@ -96,7 +98,7 @@ def _get_pose_bone_location_and_rotation(
     return location, rotation
 
 
-def build_psa(context: bpy.types.Context, options: PsaBuildOptions) -> Psa:
+def build_psa(context: Context, options: PsaBuildOptions) -> Psa:
     psa = Psa()
 
     psx_bone_create_result = create_psx_bones(
diff --git a/io_scene_psk_psa/psa/data.py b/io_scene_psk_psa/psa/data.py
index 5dd82cc..0c1cd0b 100644
--- a/io_scene_psk_psa/psa/data.py
+++ b/io_scene_psk_psa/psa/data.py
@@ -2,15 +2,15 @@ import typing
 from collections import OrderedDict
 from typing import List
 
-from ..shared.data import *
-
-'''
-Note that keys are not stored within the Psa object.
-Use the PsaReader::get_sequence_keys to get the keys for a sequence.
-'''
+from ctypes import Structure, c_char, c_int32, c_float
+from ..shared.data import PsxBone, Quaternion, Vector3
 
 
 class Psa:
+    '''
+    Note that keys are not stored within the Psa object.
+    Use the PsaReader::get_sequence_keys to get the keys for a sequence.
+    '''
 
     class Sequence(Structure):
         _fields_ = [
diff --git a/io_scene_psk_psa/psa/import_/operators.py b/io_scene_psk_psa/psa/import_/operators.py
index 6649698..0169d91 100644
--- a/io_scene_psk_psa/psa/import_/operators.py
+++ b/io_scene_psk_psa/psa/import_/operators.py
@@ -2,13 +2,13 @@ import os
 from pathlib import Path
 from typing import Iterable
 
-from bpy.props import StringProperty, CollectionProperty
-from bpy.types import Operator, Event, Context, FileHandler, OperatorFileListElement, Object
+from bpy.props import CollectionProperty, StringProperty
+from bpy.types import Context, Event, FileHandler, Object, Operator, OperatorFileListElement
 from bpy_extras.io_utils import ImportHelper
 
-from .properties import get_visible_sequences, PsaImportMixin
+from .properties import PsaImportMixin, get_visible_sequences
 from ..config import read_psa_config
-from ..importer import import_psa, PsaImportOptions
+from ..importer import PsaImportOptions, import_psa
 from ..reader import PsaReader
 
 
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 4855708..6bb6ec3 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -3,7 +3,7 @@ from typing import List, Optional
 
 import bpy
 import numpy as np
-from bpy.types import FCurve, Object, Context
+from bpy.types import Context, FCurve, Object
 from mathutils import Vector, Quaternion
 
 from .config import PsaConfig, REMOVE_TRACK_LOCATION, REMOVE_TRACK_ROTATION
diff --git a/io_scene_psk_psa/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index c5ccf89..1869707 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -3,7 +3,8 @@ from typing import List
 
 import numpy as np
 
-from .data import Psa, Section, PsxBone
+from .data import Psa, PsxBone
+from ..shared.data import Section
 
 
 def _try_fix_cue4parse_issue_103(sequences) -> bool:
diff --git a/io_scene_psk_psa/psa/writer.py b/io_scene_psk_psa/psa/writer.py
index 05001cb..015c1e5 100644
--- a/io_scene_psk_psa/psa/writer.py
+++ b/io_scene_psk_psa/psa/writer.py
@@ -2,7 +2,7 @@ from ctypes import Structure, sizeof
 from typing import Type
 
 from .data import Psa
-from ..shared.data import Section, PsxBone
+from ..shared.data import PsxBone, Section
 
 
 def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
diff --git a/io_scene_psk_psa/psk/builder.py b/io_scene_psk_psa/psk/builder.py
index 4224d85..09a2288 100644
--- a/io_scene_psk_psa/psk/builder.py
+++ b/io_scene_psk_psa/psk/builder.py
@@ -1,15 +1,15 @@
 import typing
-from typing import Dict, Generator, Set, Iterable, Optional, cast, Tuple
+from typing import Dict, Generator, Set, Iterable, Optional, cast, Tuple, List
 
 import bmesh
 import bpy
 import numpy as np
-from bpy.types import Collection, Context, Object, Armature
+from bpy.types import Collection, Context, Object, Armature, Depsgraph
 from mathutils import Matrix
 
-from .data import *
-from .export.operators import get_materials_for_mesh_objects
+from .data import Psk
 from .properties import triangle_type_and_bit_flags_to_poly_flags
+from ..shared.data import Vector3
 from ..shared.dfs import dfs_collection_objects, dfs_view_layer_objects, DfsObject
 from ..shared.helpers import convert_string_to_cp1252_bytes, \
     create_psx_bones, get_coordinate_system_transform
@@ -35,6 +35,19 @@ class PskBuildOptions(object):
         self.root_bone_name = 'ROOT'
 
 
+def get_materials_for_mesh_objects(depsgraph: Depsgraph, mesh_objects: Iterable[Object]):
+    yielded_materials = set()
+    for mesh_object in mesh_objects:
+        evaluated_mesh_object = mesh_object.evaluated_get(depsgraph)
+        for i, material_slot in enumerate(evaluated_mesh_object.material_slots):
+            material = material_slot.material
+            if material is None:
+                raise RuntimeError('Material slot cannot be empty (index ' + str(i) + ')')
+            if material not in yielded_materials:
+                yielded_materials.add(material)
+                yield material
+
+
 def get_mesh_objects_for_collection(collection: Collection) -> Iterable[DfsObject]:
     return filter(lambda x: x.obj.type == 'MESH', dfs_collection_objects(collection))
 
@@ -95,8 +108,8 @@ class PskBuildResult(object):
         self.warnings: List[str] = []
 
 
-def _get_mesh_export_space_matrix(armature_objects: Iterable[Object], export_space: str) -> Matrix:
-    if not armature_objects:
+def _get_mesh_export_space_matrix(armature_object: Object, export_space: str) -> Matrix:
+    if armature_object is None:
         return Matrix.Identity(4)
 
     def get_object_space_space_matrix(obj: Object) -> Matrix:
@@ -104,15 +117,12 @@ def _get_mesh_export_space_matrix(armature_objects: Iterable[Object], export_spa
         # We neutralize the scale here because the scale is already applied to the mesh objects implicitly.
         return Matrix.Translation(translation) @ rotation.to_matrix().to_4x4()
 
-
     match export_space:
         case 'WORLD':
             return Matrix.Identity(4)
         case 'ARMATURE':
-            return get_object_space_space_matrix(armature_objects[0]).inverted()
+            return get_object_space_space_matrix(armature_object).inverted()
         case 'ROOT':
-            # TODO: multiply this by the root bone's local matrix
-            armature_object = armature_objects[0]
             armature_data = cast(armature_object.data, Armature)
             armature_space_matrix = get_object_space_space_matrix(armature_object) @ armature_data.bones[0].matrix_local
             return armature_space_matrix.inverted()
@@ -189,9 +199,14 @@ def build_psk(context: Context, input_objects: PskInputObjects, options: PskBuil
     context.window_manager.progress_begin(0, len(input_objects.mesh_dfs_objects))
 
     coordinate_system_matrix = get_coordinate_system_transform(options.forward_axis, options.up_axis)
-    mesh_export_space_matrix = _get_mesh_export_space_matrix(armature_objects, options.export_space)
+
+    # TODO: we need to store this per armature
+    armature_mesh_export_space_matrices: Dict[Optional[Object], Matrix] = dict()
+
+    for armature_object in armature_objects:
+        armature_mesh_export_space_matrices[armature_object] = _get_mesh_export_space_matrix(armature_object, options.export_space)
+
     scale_matrix = Matrix.Scale(options.scale, 4)
-    vertex_transform_matrix = scale_matrix @ coordinate_system_matrix @ mesh_export_space_matrix
 
     original_armature_object_pose_positions = {armature_object: armature_object.data.pose_position for armature_object in armature_objects}
 
@@ -265,7 +280,8 @@ def build_psk(context: Context, input_objects: PskInputObjects, options: PskBuil
             case _:
                 assert False, f'Invalid object evaluation state: {options.object_eval_state}'
 
-        vertex_offset = len(psk.points)
+        mesh_export_space_matrix = armature_mesh_export_space_matrices[armature_object]
+        vertex_transform_matrix = scale_matrix @ coordinate_system_matrix @ mesh_export_space_matrix
         point_transform_matrix = vertex_transform_matrix @ mesh_object.matrix_world
 
         # Vertices
@@ -282,6 +298,8 @@ def build_psk(context: Context, input_objects: PskInputObjects, options: PskBuil
         # Wedges
         mesh_data.calc_loop_triangles()
 
+        vertex_offset = len(psk.points)
+
         # Build a list of non-unique wedges.
         wedges = []
         for loop_index, loop in enumerate(mesh_data.loops):
diff --git a/io_scene_psk_psa/psk/export/operators.py b/io_scene_psk_psa/psk/export/operators.py
index f737c2d..dbbd9e3 100644
--- a/io_scene_psk_psa/psk/export/operators.py
+++ b/io_scene_psk_psa/psk/export/operators.py
@@ -1,32 +1,19 @@
 from pathlib import Path
-from typing import List, Optional, cast, Iterable
+from typing import Iterable, List, Optional, cast
 
 import bpy
-from bpy.props import StringProperty, BoolProperty
-from bpy.types import Operator, Context, Object, Collection, SpaceProperties, Depsgraph, Material
+from bpy.props import BoolProperty, StringProperty
+from bpy.types import Collection, Context, Depsgraph, Material, Object, Operator, SpaceProperties
 from bpy_extras.io_utils import ExportHelper
 
 from .properties import PskExportMixin
-from ..builder import build_psk, PskBuildOptions, get_psk_input_objects_for_context, \
-    get_psk_input_objects_for_collection
+from ..builder import PskBuildOptions, build_psk, get_psk_input_objects_for_context, \
+    get_psk_input_objects_for_collection, get_materials_for_mesh_objects
 from ..writer import write_psk
 from ...shared.helpers import populate_bone_collection_list
 from ...shared.ui import draw_bone_filter_mode
 
 
-def get_materials_for_mesh_objects(depsgraph: Depsgraph, mesh_objects: Iterable[Object]):
-    yielded_materials = set()
-    for mesh_object in mesh_objects:
-        evaluated_mesh_object = mesh_object.evaluated_get(depsgraph)
-        for i, material_slot in enumerate(evaluated_mesh_object.material_slots):
-            material = material_slot.material
-            if material is None:
-                raise RuntimeError('Material slot cannot be empty (index ' + str(i) + ')')
-            if material not in yielded_materials:
-                yielded_materials.add(material)
-                yield material
-
-
 def populate_material_name_list(depsgraph: Depsgraph, mesh_objects: Iterable[Object], material_list):
     materials = list(get_materials_for_mesh_objects(depsgraph, mesh_objects))
 
diff --git a/io_scene_psk_psa/psk/reader.py b/io_scene_psk_psa/psk/reader.py
index 7feb8fc..64c1fbd 100644
--- a/io_scene_psk_psa/psk/reader.py
+++ b/io_scene_psk_psa/psk/reader.py
@@ -3,8 +3,10 @@ import os
 import re
 import warnings
 from pathlib import Path
+from typing import List
 
-from .data import *
+from ..shared.data import Section
+from .data import Color, Psk, PsxBone, Vector2, Vector3
 
 
 def _read_types(fp, data_class, section: Section, data):
diff --git a/io_scene_psk_psa/shared/data.py b/io_scene_psk_psa/shared/data.py
index eabbae3..7e4b924 100644
--- a/io_scene_psk_psa/shared/data.py
+++ b/io_scene_psk_psa/shared/data.py
@@ -1,4 +1,4 @@
-from ctypes import *
+from ctypes import Structure, c_char, c_int32, c_float, c_ubyte
 from typing import Tuple
 
 from bpy.props import EnumProperty