feat: Add VRM Blender addon with complete import/export functionality

- Add core VRM addon infrastructure with manifest and registration
- Add common utilities module with file system, logging, and conversion helpers
- Add human bone mapper with support for multiple rigging standards (Mixamo, MMD, Unreal, Rigify, etc.)
- Add VRM 0.x and 1.x format support with property groups and handlers
- Add editor UI panels for VRM metadata, spring bones, and MToon materials
- Add exporter with glTF2 extension support for VRM format serialization
- Add importer with scene reconstruction and armature generation
- Add MToon shader support with auto-setup and material migration
- Add spring bone physics simulation with constraint handling
- Add node constraint editor for advanced rigging control
- Add comprehensive validation and error handling with user dialogs
- Add scene watcher for real-time property synchronization
- Add workspace management and preference system
- Include Python cache files and Blender manifest configuration
- This is the initial commit establishing the complete VRM addon ecosystem for Blender

common/mtoon_unversioned.py

@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: MIT OR GPL-3.0-or-later
+from collections.abc import Mapping
+from typing import ClassVar, Optional
+
+
+class MtoonUnversioned:
+    # {key = MToonProp, val = ShaderNodeGroup_member_name}
+    version = 32
+    float_props_exchange_dict: Mapping[str, Optional[str]] = {
+        "_MToonVersion": None,
+        "_Cutoff": "CutoffRate",
+        "_BumpScale": "BumpScale",
+        "_ReceiveShadowRate": "ReceiveShadowRate",
+        "_ShadeShift": "ShadeShift",
+        "_ShadeToony": "ShadeToony",
+        "_RimLightingMix": "RimLightingMix",
+        "_RimFresnelPower": "RimFresnelPower",
+        "_RimLift": "RimLift",
+        "_ShadingGradeRate": "ShadingGradeRate",
+        "_LightColorAttenuation": "LightColorAttenuation",
+        "_IndirectLightIntensity": "IndirectLightIntensity",
+        "_OutlineWidth": "OutlineWidth",
+        "_OutlineScaledMaxDistance": "OutlineScaleMaxDistance",
+        "_OutlineLightingMix": "OutlineLightingMix",
+        "_UvAnimScrollX": "UV_Scroll_X",  # TODO: #####
+        "_UvAnimScrollY": "UV_Scroll_Y",  # TODO: #####
+        "_UvAnimRotation": "UV_Scroll_Rotation",  # TODO: #####
+        "_DebugMode": None,
+        "_BlendMode": None,
+        "_OutlineWidthMode": "OutlineWidthMode",
+        "_OutlineColorMode": "OutlineColorMode",
+        "_CullMode": None,
+        "_OutlineCullMode": None,
+        "_SrcBlend": None,
+        "_DstBlend": None,
+        "_ZWrite": None,
+        "_IsFirstSetup": None,
+    }
+
+    texture_kind_exchange_dict: Mapping[str, str] = {
+        "_MainTex": "MainTexture",
+        "_ShadeTexture": "ShadeTexture",
+        "_BumpMap": "NormalmapTexture",
+        "_ReceiveShadowTexture": "ReceiveShadow_Texture",
+        "_ShadingGradeTexture": "ShadingGradeTexture",
+        "_EmissionMap": "Emission_Texture",
+        "_SphereAdd": "SphereAddTexture",
+        "_RimTexture": "RimTexture",
+        "_OutlineWidthTexture": "OutlineWidthTexture",
+        "_UvAnimMaskTexture": "UV_Animation_Mask_Texture",  # TODO: ####
+    }
+    vector_base_props_exchange_dict: Mapping[str, str] = {
+        "_Color": "DiffuseColor",
+        "_ShadeColor": "ShadeColor",
+        "_EmissionColor": "EmissionColor",
+        "_RimColor": "RimColor",
+        "_OutlineColor": "OutlineColor",
+    }
+    # texture offset and scaling props by texture
+    vector_props_exchange_dict: ClassVar[dict[str, str]] = {}
+    vector_props_exchange_dict.update(vector_base_props_exchange_dict)
+    vector_props_exchange_dict.update(texture_kind_exchange_dict)