init: animation pipeline hub — Mac↔PC bridge for converting and implementing animations

Skills (.claude/skills/): animation-creation, iclone-video-mocap,
pose-estimation (MediaPipe models via LFS), retarget-animations (deprecated).
Tools: cc/mixamo/kevin/mocap retargeters + composite baker.
Plans: animation-gen-pipeline + skills-adoption.
exchange/: incoming-fbx, converted-glb, reference-video (LFS for fbx/glb/mp4).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.claude/skills/retarget-animations/SKILL.md

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+# Skill: Animation Retargeting (Kevin → BoZo) — DEPRECATED
+
+**DEPRECATED May 19, 2026.** BoZo and Kevin characters retired. Quaternius character system replaces them — no retargeting needed. This skill is kept for engine reference (Godot fork rest fixer fix).
+
+```bash
+# 1. Clean import (creates default .import files)
+rm -f assets/animations/kevin/*.import assets/models/characters/Body/Body_BasicBody.fbx.import
+rm -f .godot/imported/Archer*.scn .godot/imported/Body_BasicBody*.scn .godot/imported/Villager*.scn .godot/imported/Throwing*.scn
+godot --headless --path . --import
+
+# 2. Patch .import files with BoneMap + retarget config
+godot --headless --path . -s setup_retarget.gd
+
+# 3. Delete cache + reimport with retarget config
+rm -f .godot/imported/Archer*.scn .godot/imported/Body_BasicBody*.scn .godot/imported/Villager*.scn .godot/imported/Throwing*.scn
+godot --headless --path . --import
+```
+
+IMPORTANT: Must delete `.godot/imported/*.scn` cache between steps 2→3, otherwise Godot skips reimport.
+
+## What the pipeline does
+
+1. **Bone renamer:** Renames Kevin bones (`B-hips` → `Hips`) and BoZo bones (`pelvis` → `Hips`) to Humanoid standard
+2. **Overwrite Axis (method 1):** Changes skeleton rest poses to match SkeletonProfileHumanoid reference
+3. **Animation conversion:** Transforms keyframe values from old rest coordinate system to new rest coordinate system using formula from `post_import_plugin_skeleton_rest_fixer.cpp:777`:
+   ```
+   new_q = new_pg_q.inv * old_pg_q * qt * old_rest_q.inv * old_pg_q.inv * new_pg_q * new_rest_q
+   ```
+
+## Known Bug (patched in tinqs/godot fork)
+
+**Commit:** `4e16c3f5bd` on `main`
+
+The `%GeneralSkeleton` unique node resolution via `get_node()` fails in headless import mode. Original code at line 733:
+```cpp
+Node *node = (ap->get_node(ap->get_root_node()))->get_node(NodePath(track_path));
+ERR_CONTINUE(!node);  // Silently skips ALL animation tracks!
+```
+
+**Fix:** Falls back to `find_child()` when unique name resolution fails. Without this fix, rest poses change but animation keyframe values stay in the old coordinate system.
+
+## Current Status (2026-05-18)
+
+**Working:**
+- Bone renaming (Kevin → Humanoid, BoZo → Humanoid) ✓
+- Rest pose overwrite to Humanoid reference ✓
+- Skeleton node resolution fix (find_child fallback) ✓
+- Animation conversion runs for spine/chest bones ✓
+
+**NOT working:**
+- Animation conversion appears to be a NO-OP for limb bones (arms, legs)
+- Spine keys → near identity (correct). Arm/leg keys → near rest (unconverted)
+- Root cause: unknown. Possibly old_rest captured AFTER partial overwrite, or formula output matches input for bones with specific rest orientations
+
+**Visual symptoms:**
+- Arms cross behind back during animation
+- Legs may be double-rotated (rest * rest)
+- Spine animates correctly
+
+## Bone Mapping
+
+### Kevin → Humanoid
+| Humanoid | Kevin |
+|----------|-------|
+| Hips | B-hips |
+| Spine | B-spine |
+| Chest | B-chest |
+| UpperChest | B-upperChest |
+| Neck | B-neck |
+| Head | B-head |
+| LeftShoulder | B-shoulder.L |
+| LeftUpperArm | B-upper_arm.L |
+| LeftLowerArm | B-forearm.L |
+| LeftHand | B-hand.L |
+| Right* | B-*.R (mirror) |
+| LeftUpperLeg | B-thigh.L |
+| LeftLowerLeg | B-shin.L |
+| LeftFoot | B-foot.L |
+| LeftToes | B-toe.L |
+| Right* | B-*.R (mirror) |
+
+### BoZo → Humanoid
+| Humanoid | BoZo |
+|----------|------|
+| Hips | pelvis |
+| Spine | spine_01 |
+| Chest | spine_03 |
+| UpperChest | spine_05 |
+| Neck | neck_01 |
+| Head | head |
+| LeftShoulder | clavicle_l |
+| LeftUpperArm | upperarm_l |
+| LeftLowerArm | lowerarm_l |
+| LeftHand | hand_l |
+| Right* | *_r (mirror) |
+| LeftUpperLeg | thigh_l |
+| LeftLowerLeg | calf_l |
+| LeftFoot | foot_l |
+| LeftToes | ball_l |
+| Right* | *_r (mirror) |
+
+BoZo intermediate bones (spine_02, spine_04, neck_02) have no Kevin equivalent and keep global rest.
+
+## Key Files
+
+| File | Purpose |
+|------|---------|
+| `setup_retarget.gd` | Headless script: patches .import files with BoneMap + retarget config |
+| `run_retarget.gd` | EditorScript: same but runs inside Godot editor GUI |
+| `addons/retarget_setup/plugin.gd` | EditorPlugin: auto-runs on editor start |
+| `assets/retarget/kevin_bonemap.tres` | Kevin → Humanoid BoneMap resource |
+| `assets/retarget/bozo_bonemap.tres` | BoZo → Humanoid BoneMap resource |
+| `inspect_fbx.gd` | Debug: prints bone names, rest poses, animation values |
+| `src/Viewer/PlayerController.cs` | Character: loads animation, remaps %GeneralSkeleton paths |
+
+## Godot Engine Source (for debugging)
+
+| File | What |
+|------|------|
+| `editor/import/3d/post_import_plugin_skeleton_rest_fixer.cpp` | Overwrite Axis + animation conversion |
+| `editor/import/3d/post_import_plugin_skeleton_renamer.cpp` | Bone renaming |
+| `scene/3d/retarget_modifier_3d.cpp` | Runtime retargeting (RetargetModifier3D) |
+| `scene/resources/bone_map.cpp` | BoneMap resource |
+| `scene/resources/skeleton_profile.cpp` | SkeletonProfile + Humanoid preset |
+
+## What NOT to do
+
+1. **Manual quaternion retargeting in C#** — tried 5 different formulas, all failed. The formula requires parent GLOBAL rest transforms for the entire bone chain. Only Godot's engine code handles this correctly.
+2. **Rename BoZo bones at runtime** — breaks outfit/clothing FBX loading (bone name mismatch).
+3. **BoneAttachment3D for head without inverse rest compensation** — double-transforms the head.
+4. **Headless import without deleting .scn cache** — Godot skips reimport if source FBX unchanged.