feat: Add KoikatsuBlenderPipeline addon with import/export functionality

- Add core addon files (__init__.py, KKPanel.py, preferences.py, common.py)
- Add import pipeline with armature, mesh, and material modification modules
- Add export pipeline with material baking and FBX preparation utilities
- Add material combiner tool for texture atlas generation and optimization
- Add extras utilities for animation, rigging, and asset management
- Add bone orientation data from better_fbx for accurate skeletal structure
- Add comprehensive documentation and wiki with multi-language support (EN, JP, ZH)
- Add animation library retargeting lists for ARP and Rokoko motion capture
- Add Rigify integration scripts for advanced rigging workflows
- Add shader file (KK Shader V8.0.blend) for material rendering
- Add manifest and license files for addon distribution
- Add changelog documenting version history and improvements
- Initialize complete Blender addon project for Koikatsu character import/export

exporting/material_combiner/objects.py

@@ -0,0 +1,38 @@
+import math
+from collections import defaultdict
+from typing import List, Dict
+
+import bpy
+from mathutils import Vector
+
+
+def get_polys(ob: bpy.types.Object) -> Dict[int, bpy.types.MeshPolygon]:
+    polys = defaultdict(list)
+    for poly in ob.data.polygons:
+        polys[poly.material_index].append(poly)
+    return polys
+
+
+def get_uv(ob: bpy.types.Object, poly: bpy.types.MeshPolygon) -> List[Vector]:
+    data = ob.data.uv_layers.active.data
+    return [data[loop_idx].uv if loop_idx < len(data) else Vector((0, 0, 0)) for loop_idx in poly.loop_indices]
+
+
+def align_uv(face_uv: List[Vector]) -> List[Vector]:
+    min_x = float('inf')
+    min_y = float('inf')
+
+    for uv in face_uv:
+        if not math.isnan(uv.x):
+            min_x = min(min_x, uv.x)
+        if not math.isnan(uv.y):
+            min_y = min(min_y, uv.y)
+
+    min_x = math.floor(min_x)
+    min_y = math.floor(min_y)
+
+    if min_x != 0 or min_y != 0:
+        for uv in face_uv:
+            uv.x -= min_x
+            uv.y -= min_y
+    return face_uv