diff --git a/.specstory/history/2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md b/.specstory/history/2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md index 68003fb..7012cb8 100644 --- a/.specstory/history/2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md +++ b/.specstory/history/2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md @@ -9073,8 +9073,6 @@ _**Agent (model default, mode Agent)**_ - - --- @@ -9121,8 +9119,6 @@ Status: **completed** - - --- @@ -9167,7 +9163,6 @@ Status: **completed** --- - The hierarchy is now: **spine_fk** → **spine_fk.001** → **spine_fk.002** → **spine_fk.003** @@ -9186,8 +9181,6 @@ _**Agent (model default, mode Agent)**_ - - --- @@ -9246,215 +9239,26 @@ Parameters: "caseInsensitive": false } ``` -Result: +Additional data: ```json { - "success": { - "pattern": "hips|MCH-WGT-hips", - "path": "D:\\2025-12-28 ytshorts gigaproj", - "outputMode": "content", - "workspaceResults": { - "D:\\2025-12-28 ytshorts gigaproj": { - "content": { - "matches": [ - { - "file": ".\\.specstory\\history\\2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md", - "matches": [ - { - "lineNumber": 2471, - "content": " \"parameters\": \"{\\\"code\\\":\\\"import bpy\\\\n\\\\narmature = bpy.context.active_object\\\\nif armature and armature.type == 'ARMATURE':\\\\n if armature.mode != 'POSE':\\\\n bpy.ops.object.mode_set(mode='POSE')\\\\n \\\\n print(\\\\\\\"Checking IK chain relationships...\\\\\\\\n\\\\\\\")\\\\n \\\\n # Check if Spine1_jnt has IK that targets Spine1_jnt.002\\\\n spine1 = armature.pose.bones.get('Spine1_jnt')\\\\n if spine1:\\\\n print(\\\\\\\"Spine1_jnt IK constraints:\\\\\\\")\\\\n for constraint in spine1.constraints:\\\\n if constraint.type == 'IK' and constraint.enabled:\\\\n print(f\\\\\\\" - IK: {constraint.name}\\\\\\\")\\\\n if hasattr(constraint, 'subtarget'):\\\\n print(f\\\\\\\" └─ Target: {constraint.subtarget}\\\\\\\")\\\\n if constraint.subtarget == 'Spine1_jnt.002':\\\\n print(f\\\\\\\" ⚠️ This IK targets Spine1_jnt.002\\\\\\\")\\\\n print(f\\\\\\\" So Spine1_jnt.002 is part of the I [... omitted end of long line]" - }, - { - "lineNumber": 2488, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: Checking IK chain relationships...\\\\n\\\\nSpine1_jnt IK constraints:\\\\n - IK: IK\\\\n └─ Target: Spine1_jnt.002\\\\n ⚠️ This IK targets Spine1_jnt.002\\\\n So Spine1_jnt.002 is part of the IK chain\\\\n\\\\nSpine1_jnt.002 constraints:\\\\n - COPY_LOCATION: Copy Location\\\\n └─ Target: Spine1_jnt.001\\\\n\\\\nChecking if Spine1_jnt.002 copies from Spine1_jnt.001...\\\\n ⚠️ Found COPY_LOCATION copying from Spine1_jnt.001\\\\n This creates a cycle: Spine1_jnt.002 (IK target) → Spine1_jnt.001 → Spine_jnt → IK chain\\\\n Removing...\\\\n ✓ Removed\\\\n\\\\n============================================================\\\\nAll dependency cycles should now be fixed!\\\\n============================================================\\\\n\\\"}]}\"" - }, - { - "lineNumber": 7542, - "content": "- `ORG-pelvis.L` and `ORG-pelvis.R` → torso (hips follow spine)" - }, - { - "lineNumber": 8183, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: ============================================================\\\\nSpine FK bone hierarchy analysis:\\\\n============================================================\\\\n\\\\nspine_fk:\\\\n Parent: MCH-spine\\\\n Children: ['tweak_spine', 'tweak_spine.001', 'MCH-WGT-hips']\\\\n\\\\nspine_fk.001:\\\\n Parent: MCH-spine.001\\\\n Children: ['MCH-spine']\\\\n\\\\nMCH-spine.001:\\\\n Parent: torso\\\\n Children: ['spine_fk.001']\\\\n\\\\nMCH-spine.002:\\\\n Parent: torso\\\\n Children: ['spine_fk.002']\\\\n\\\\nMCH-spine:\\\\n Parent: spine_fk.001\\\\n Children: ['spine_fk']\\\\n\\\\ntweak_spine:\\\\n Parent: spine_fk\\\\n Children: ['ORG-spine']\\\\n\\\\nORG-spine:\\\\n Parent: tweak_spine\\\\n Children: ['ORG-thigh.L', 'ORG-thigh.R', 'MCH-thigh_tweak.L', 'DEF-thigh.L', 'MCH-thigh_tweak.R', 'DEF-thigh.R']\\\\n\\\\n\\\\n============================================================\\\\nUnderstanding 'control upwards' vs 'control downwards':\\\\n--------------------- [... omitted end of long line]" - }, - { - "lineNumber": 8363, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: DEF-spine: parent=torso, children=['DEF-spine.001'], head=[-6.040692966858717e-15, -0.05290958285331726, 0.9631017446517944], tail=[-2.8751468250616053e-15, -0.053293343633413315, 1.1857341527938843]\\\\nDEF-spine.001: parent=DEF-spine, children=['DEF-spine.002'], head=[-2.8751468250616053e-15, -0.053293343633413315, 1.1857341527938843], tail=[-7.753174204673573e-16, -0.053802844136953354, 1.2668348550796509]\\\\nDEF-spine.002: parent=DEF-spine.001, children=['DEF-spine.003'], head=[-7.753174204673573e-16, -0.053802844136953354, 1.2668348550796509], tail=[-1.0016046863702433e-14, -0.053894929587841034, 1.3369754552841187]\\\\nDEF-spine.003: parent=DEF-spine.002, children=[], head=[-1.0016046863702433e-14, -0.053894929587841034, 1.3369754552841187], tail=[-3.2490951423736706e-15, -0.003184385597705841, 1.567861795425415]\\\\nMCH-spine.001: parent=torso, children=['spine_fk.001'], head=[-5.7875366598013e-18, -0. [... omitted end of long line]" - }, - { - "lineNumber": 8411, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: \\\\nspine_fk:\\\\n\\\\nspine_fk.001:\\\\n\\\\nMCH-spine:\\\\n - COPY_TRANSFORMS: target=<bpy_struct, Object(\\\\\\\"Vanessa\\\\\\\") at 0x0000021E7844B920>, subtarget=hips\\\\n\\\\nMCH-spine.001:\\\\n - COPY_TRANSFORMS: target=<bpy_struct, Object(\\\\\\\"Vanessa\\\\\\\") at 0x0000021E7844B920>, subtarget=hips\\\\n\\\\nspine_fk.002:\\\\n\\\\nspine_fk.003:\\\\n\\\\nMCH-spine.002:\\\\n - COPY_TRANSFORMS: target=<bpy_struct, Object(\\\\\\\"Vanessa\\\\\\\") at 0x0000021E7844B920>, subtarget=chest\\\\n\\\\nMCH-spine.003:\\\\n - COPY_TRANSFORMS: target=<bpy_struct, Object(\\\\\\\"Vanessa\\\\\\\") at 0x0000021E7844B920>, subtarget=chest\\\\n\\\"}]}\"" - }, - { - "lineNumber": 8507, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: DEF-spine (z: 0.963-1.186)\\\\n DEF-spine.001 (z: 1.186-1.267)\\\\n DEF-spine.002 (z: 1.267-1.337)\\\\n DEF-spine.003 (z: 1.337-1.568)\\\\n\\\\nMCH-spine.001 (z: 1.267-1.267)\\\\n spine_fk.001 (z: 1.267-1.348)\\\\n MCH-spine (z: 1.186-1.186)\\\\n spine_fk (z: 1.186-1.408)\\\\n tweak_spine (z: 0.963-1.074)\\\\n ORG-spine (z: 0.963-1.186)\\\\n ORG-thigh.L (z: 0.995-0.579)\\\\n ORG-shin.L (z: 0.579-0.117)\\\\n ORG-foot.L (z: 0.117-0.023)\\\\n ORG-toe.L (z: 0.023-0.047)\\\\n ORG-heel.02.L (z: -0.000--0.000)\\\\n MCH-toe.L (z: 0.023-0.023)\\\\n toe.L (z: 0.023-0.047)\\\\n MCH-foot_tweak.L (z: 0.117-0.105)\\\\n foot_tweak.L (z: 0.117-0.093)\\\\n MCH-shin_tweak.L (z: 0.579-0.521)\\\\n shin_tweak.L (z: 0.579-0.463)\\\\n MCH-shin_tw [... omitted end of long line]" - }, - { - "lineNumber": 8675, - "content": "That's not right, now spine_fk.001 does nothing (when rotated). spine_fk does effectively the exact same thing as 'hips', but it should be doing spine things." - }, - { - "lineNumber": 8682, - "content": "Investigating how the spine chain drives deformation and how it connects to the hips:" - }, - { - "lineNumber": 8699, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\npb = arm.pose.bones\\\\n\\\\n# Check constraints on all spine-related bones\\\\nspine_bones = [\\\\\\\"spine_fk\\\\\\\", \\\\\\\"spine_fk.001\\\\\\\", \\\\\\\"spine_fk.002\\\\\\\", \\\\\\\"spine_fk.003\\\\\\\", \\\\n \\\\\\\"MCH-spine\\\\\\\", \\\\\\\"MCH-spine.001\\\\\\\", \\\\\\\"MCH-spine.002\\\\\\\", \\\\\\\"MCH-spine.003\\\\\\\",\\\\n \\\\\\\"tweak_spine\\\\\\\", \\\\\\\"tweak_spine.001\\\\\\\", \\\\\\\"tweak_spine.002\\\\\\\", \\\\\\\"tweak_spine.003\\\\\\\", \\\\\\\"tweak_spine.004\\\\\\\",\\\\n \\\\\\\"hips\\\\\\\", \\\\\\\"chest\\\\\\\", \\\\\\\"ORG-spine\\\\\\\", \\\\\\\"ORG-spine.001\\\\\\\", \\\\\\\"ORG-spine.002\\\\\\\", \\\\\\\"ORG-spine.003\\\\\\\"]\\\\n\\\\nfor name in spine_bones:\\\\n if name in pb:\\\\n b = pb[name]\\\\n print(f\\\\\\\"\\\\\\\\n{b.name}:\\\\\\\")\\\\n for c in b.constraints:\\\\n tgt = getattr(c, 'target', None)\\\\n sub = getattr(c, 'subtarget', '')\\\\n print(f\\\\\\\" {c.type}: target={tgt.name if tgt else None}, subtarget={sub}\\\\\\\")\\\\n\\\",\\\"user_promp [... omitted end of long line]" - }, - { - "lineNumber": 8716, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: \\\\nspine_fk:\\\\n\\\\nspine_fk.001:\\\\n\\\\nspine_fk.002:\\\\n\\\\nspine_fk.003:\\\\n\\\\nMCH-spine:\\\\n COPY_TRANSFORMS: target=Vanessa, subtarget=hips\\\\n\\\\nMCH-spine.001:\\\\n COPY_TRANSFORMS: target=Vanessa, subtarget=hips\\\\n\\\\nMCH-spine.002:\\\\n COPY_TRANSFORMS: target=Vanessa, subtarget=chest\\\\n\\\\nMCH-spine.003:\\\\n COPY_TRANSFORMS: target=Vanessa, subtarget=chest\\\\n\\\\ntweak_spine:\\\\n\\\\ntweak_spine.001:\\\\n\\\\ntweak_spine.002:\\\\n\\\\ntweak_spine.003:\\\\n\\\\ntweak_spine.004:\\\\n\\\\nhips:\\\\n\\\\nchest:\\\\n\\\\nORG-spine:\\\\n\\\\nORG-spine.001:\\\\n\\\\nORG-spine.002:\\\\n\\\\nORG-spine.003:\\\\n\\\"}]}\"" - }, - { - "lineNumber": 8738, - "content": " \"pattern\": \"spine_fk|tweak_spine|hips|chest\"," - }, - { - "lineNumber": 8749, - "content": " \"pattern\": \"spine_fk|tweak_spine|hips|chest\"," - }, - { - "lineNumber": 8803, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: spine_fk.002 children: ['MCH-pivot', 'MCH-spine.003']\\\\nspine_fk.003 children: ['tweak_spine.003', 'tweak_spine.004', 'MCH-WGT-chest']\\\\n\\\\nspine_fk children: ['MCH-spine', 'tweak_spine', 'tweak_spine.001', 'MCH-WGT-hips']\\\\nspine_fk.001 children: []\\\\n\\\\ntweak_spine children: ['ORG-spine']\\\\ntweak_spine.001 children: ['ORG-spine.001']\\\\n\\\"}]}\"" - }, - { - "lineNumber": 8876, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\n\\\\n# Find hips and chest - their parents and children\\\\nfor name in [\\\\\\\"hips\\\\\\\", \\\\\\\"chest\\\\\\\", \\\\\\\"torso\\\\\\\"]:\\\\n if name in bones:\\\\n b = bones[name]\\\\n print(f\\\\\\\"{name}: parent={b.parent.name if b.parent else None}\\\\\\\")\\\\n print(f\\\\\\\" children: {[c.name for c in b.children]}\\\\\\\")\\\\n print()\\\\n\\\\n# ORG-spine is pelvis - what drives it?\\\\nprint(\\\\\\\"tweak_spine parent:\\\\\\\", bones[\\\\\\\"tweak_spine\\\\\\\"].parent.name)\\\\nprint(\\\\\\\"ORG-spine (pelvis) parent:\\\\\\\", bones[\\\\\\\"ORG-spine\\\\\\\"].parent.name)\\\\n\\\",\\\"user_prompt\\\":\\\"hips chest hierarchy\\\"}\"," - }, - { - "lineNumber": 8893, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: hips: parent=torso\\\\n children: []\\\\n\\\\nchest: parent=torso\\\\n children: []\\\\n\\\\ntorso: parent=root\\\\n children: ['ORG-pelvis.L', 'ORG-pelvis.R', 'DEF-spine', 'VIS_thigh_ik_pole.L', 'VIS_thigh_ik_pole.R', 'hips', 'chest', 'MCH-spine.001', 'MCH-spine.002', 'MCH-thigh_parent.L', 'MCH-thigh_parent_socket.L', 'MCH-thigh_parent.R', 'MCH-thigh_parent_socket.R']\\\\n\\\\ntweak_spine parent: spine_fk\\\\nORG-spine (pelvis) parent: tweak_spine\\\\n\\\"}]}\"" - }, - { - "lineNumber": 8924, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\n\\\\n# Key insight: tweak_spine = pelvis (ORG-spine has legs as children)\\\\n# spine_fk drives tweak_spine = rotates pelvis = same as hips!\\\\n# Fix: pelvis (tweak_spine) should follow hips; spine_fk should drive only spine (tweak_spine.001)\\\\n\\\\n# spine_fk.002 chain - how is pelvis handled? There's no pelvis in upper chain.\\\\n# Lower chain: tweak_spine (pelvis) + tweak_spine.001 (spine) both under spine_fk\\\\n# So spine_fk rotates both = pelvis rotation = hips\\\\n\\\\n# Fix: 1) tweak_spine (pelvis) under MCH-spine.001 (follows hips)\\\\n# 2) spine_fk.001 drives tweak_spine.001 (spine segment)\\\\n# 3) spine_fk in chain but doesn't drive pelvis\\\\n\\\\nprint(\\\\\\\"Current MCH-spine.001 children:\\\\\\\", [c.name for c in bones[\\\\\\\"MCH-spine.001\\\\\\\"].children])\\\\n\\\",\\\"user_prompt\\\":\\\"understand pelvis vs spine\\\"}\"," - }, - { - "lineNumber": 8972, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbpy.context.view_layer.objects.active = arm\\\\nbpy.ops.object.mode_set(mode='EDIT')\\\\n\\\\neb = arm.data.edit_bones\\\\n\\\\n# 1. Move tweak_spine (pelvis) from spine_fk to MCH-spine.001 - pelvis follows hips, not spine_fk\\\\n# 2. Move tweak_spine.001 from spine_fk to spine_fk.001 - spine_fk.001 drives first spine segment\\\\n# 3. Keep hierarchy: MCH-spine.001 -> spine_fk -> MCH-spine -> spine_fk.001 (upwards)\\\\n\\\\neb[\\\\\\\"tweak_spine\\\\\\\"].parent = eb[\\\\\\\"MCH-spine.001\\\\\\\"]\\\\neb[\\\\\\\"tweak_spine.001\\\\\\\"].parent = eb[\\\\\\\"spine_fk.001\\\\\\\"]\\\\n\\\\nbpy.ops.object.mode_set(mode='POSE')\\\\nprint(\\\\\\\"Done: tweak_spine (pelvis) now follows hips; spine_fk.001 drives tweak_spine.001 (spine)\\\\\\\")\\\\n\\\",\\\"user_prompt\\\":\\\"fix pelvis and spine control separation\\\"}\"," - }, - { - "lineNumber": 8989, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: Done: tweak_spine (pelvis) now follows hips; spine_fk.001 drives tweak_spine.001 (spine)\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9037, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: MCH-spine.001 children: ['spine_fk', 'tweak_spine']\\\\nspine_fk children: ['MCH-spine', 'MCH-WGT-hips']\\\\nspine_fk.001 children: ['tweak_spine.001']\\\\ntweak_spine parent: MCH-spine.001\\\\ntweak_spine.001 parent: spine_fk.001\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9053, - "content": "1. **`tweak_spine` (pelvis)** is now parented to **MCH-spine.001** instead of `spine_fk`. The pelvis follows the hips control, so rotating `spine_fk` no longer rotates the pelvis." - }, - { - "lineNumber": 9062, - "content": "- **hips** still controls the pelvis via `tweak_spine` under MCH-spine.001." - }, - { - "lineNumber": 9181, - "content": "spine_fk still drives the hips." - }, - { - "lineNumber": 9205, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\n\\\\n# What does spine_fk drive? Trace its children\\\\nprint(\\\\\\\"spine_fk children:\\\\\\\", [c.name for c in bones[\\\\\\\"spine_fk\\\\\\\"].children])\\\\nprint(\\\\\\\"spine_fk parent:\\\\\\\", bones[\\\\\\\"spine_fk\\\\\\\"].parent.name if bones[\\\\\\\"spine_fk\\\\\\\"].parent else None)\\\\nprint()\\\\nprint(\\\\\\\"tweak_spine parent:\\\\\\\", bones[\\\\\\\"tweak_spine\\\\\\\"].parent.name if bones[\\\\\\\"tweak_spine\\\\\\\"].parent else None)\\\\nprint(\\\\\\\"tweak_spine children (ORG-spine = pelvis/hips):\\\\\\\", [c.name for c in bones[\\\\\\\"tweak_spine\\\\\\\"].children])\\\\nprint()\\\\n# MCH-WGT-hips - what does it do?\\\\nprint(\\\\\\\"MCH-WGT-hips parent:\\\\\\\", bones[\\\\\\\"MCH-WGT-hips\\\\\\\"].parent.name if bones[\\\\\\\"MCH-WGT-hips\\\\\\\"].parent else None)\\\\nprint(\\\\\\\"MCH-WGT-hips children:\\\\\\\", [c.name for c in bones[\\\\\\\"MCH-WGT-hips\\\\\\\"].children])\\\\nprint()\\\\n# Any bones that copy or constrain to spine_fk?\\\\npb = arm.pose.bones\\\\nfor name, b in pb.ite [... omitted end of long line]" - }, - { - "lineNumber": 9222, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: spine_fk children: ['MCH-spine', 'spine_fk.001', 'MCH-WGT-hips']\\\\nspine_fk parent: MCH-spine.001\\\\n\\\\ntweak_spine parent: MCH-spine.001\\\\ntweak_spine children (ORG-spine = pelvis/hips): ['ORG-spine']\\\\n\\\\nMCH-WGT-hips parent: spine_fk\\\\nMCH-WGT-hips children: []\\\\n\\\\nMCH-pivot has constraint targeting spine_fk: COPY_TRANSFORMS\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9250, - "content": " \"pattern\": \"MCH-WGT-hips|WGT-hips\"," - }, - { - "lineNumber": 9260, - "content": " \"pattern\": \"MCH-WGT-hips|WGT-hips\"," - }, - { - "lineNumber": 9272, - "content": " \"content\": \" \\\"result\\\": \\\"{\\\\\\\"content\\\\\\\":[{\\\\\\\"type\\\\\\\":\\\\\\\"text\\\\\\\",\\\\\\\"text\\\\\\\":\\\\\\\"Code executed successfully: ============================================================\\\\\\\\nSpine FK bone hierarchy analysis:\\\\\\\\n============================================================\\\\\\\\n\\\\\\\\nspine_fk:\\\\\\\\n Parent: MCH-spine\\\\\\\\n Children: ['tweak_spine', 'tweak_spine.001', 'MCH-WGT-hips']\\\\\\\\n\\\\\\\\nspine_fk.001:\\\\\\\\n Parent: MCH-spine.001\\\\\\\\n Children: ['MCH-spine']\\\\\\\\n\\\\\\\\nMCH-spine.001:\\\\\\\\n Parent: torso\\\\\\\\n Children: ['spine_fk.001']\\\\\\\\n\\\\\\\\nMCH-spine.002:\\\\\\\\n Parent: torso\\\\\\\\n Children: ['spine_fk.002']\\\\\\\\n\\\\\\\\nMCH-spine:\\\\\\\\n Parent: spine_fk.001\\\\\\\\n Children: ['spine_fk']\\\\\\\\n\\\\\\\\ntweak_spine:\\\\\\\\n Parent: spine_fk\\\\\\\\n Children: ['ORG-spine']\\\\\\\\n\\\\\\\\nORG-spine:\\\\\\\\n Parent: tweak_spine\\\\\\\\n Children: ['ORG-thigh.L', 'ORG-thigh.R', 'MCH-thigh_tweak.L', 'DEF-thigh.L', 'MCH-thigh_tweak.R', 'DEF-thigh.R']\\\\\\\\n\\\\\\\\n\\\\\\\\n========================= [... omitted end of long line]" - }, - { - "lineNumber": 9284, - "content": " \"content\": \" \\\"result\\\": \\\"{\\\\\\\"content\\\\\\\":[{\\\\\\\"type\\\\\\\":\\\\\\\"text\\\\\\\",\\\\\\\"text\\\\\\\":\\\\\\\"Code executed successfully: spine_fk.002 children: ['MCH-pivot', 'MCH-spine.003']\\\\\\\\nspine_fk.003 children: ['tweak_spine.003', 'tweak_spine.004', 'MCH-WGT-chest']\\\\\\\\n\\\\\\\\nspine_fk children: ['MCH-spine', 'tweak_spine', 'tweak_spine.001', 'MCH-WGT-hips']\\\\\\\\nspine_fk.001 children: []\\\\\\\\n\\\\\\\\ntweak_spine children: ['ORG-spine']\\\\\\\\ntweak_spine.001 children: ['ORG-spine.001']\\\\\\\\n\\\\\\\"}]}\\\"\"" - }, - { - "lineNumber": 9288, - "content": " \"content\": \" \\\"result\\\": \\\"{\\\\\\\"content\\\\\\\":[{\\\\\\\"type\\\\\\\":\\\\\\\"text\\\\\\\",\\\\\\\"text\\\\\\\":\\\\\\\"Code executed successfully: MCH-spine.001 children: ['spine_fk', 'tweak_spine']\\\\\\\\nspine_fk children: ['MCH-spine', 'MCH-WGT-hips']\\\\\\\\nspine_fk.001 children: ['tweak_spine.001']\\\\\\\\ntweak_spine parent: MCH-spine.001\\\\\\\\ntweak_spine.001 parent: spine_fk.001\\\\\\\\n\\\\\\\"}]}\\\"\"" - }, - { - "lineNumber": 9321, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\npb = arm.pose.bones\\\\n\\\\n# What references MCH-WGT-hips or drives hips?\\\\nfor name, b in pb.items():\\\\n for c in b.constraints:\\\\n sub = getattr(c, 'subtarget', '')\\\\n if 'hips' in sub.lower() or 'WGT' in sub:\\\\n print(f\\\\\\\"{name}: {c.type} -> {sub}\\\\\\\")\\\\nprint()\\\\n# What is MCH-spine's role - who is its parent and children?\\\\nprint(\\\\\\\"MCH-spine parent:\\\\\\\", bones[\\\\\\\"MCH-spine\\\\\\\"].parent.name)\\\\nprint(\\\\\\\"MCH-spine children:\\\\\\\", [c.name for c in bones[\\\\\\\"MCH-spine\\\\\\\"].children])\\\\nprint()\\\\n# Does spine_fk's rotation propagate to pelvis? tweak_spine is under MCH-spine.001\\\\n# So pelvis (tweak_spine) should NOT be under spine_fk. Good.\\\\n# But MCH-WGT-hips under spine_fk - does it affect deformation?\\\\nfor obj in bpy.data.objects:\\\\n if obj.type == 'MESH' and obj.data.vertex_groups:\\\\n for vg in obj.data.vertex_groups:\\\\n [... omitted end of long line]" - }, - { - "lineNumber": 9369, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\npb = arm.pose.bones\\\\n\\\\n# What references MCH-WGT-hips?\\\\nfor name, b in pb.items():\\\\n for c in b.constraints:\\\\n sub = getattr(c, 'subtarget', '')\\\\n if 'WGT-hips' in sub or 'hips' in sub:\\\\n print(f\\\\\\\"{name}: {c.type} -> {sub}\\\\\\\")\\\\n\\\\n# MCH-WGT-hips is child of spine_fk - when spine_fk rotates, it rotates too\\\\n# Move it to MCH-spine.001 so it follows hips, not spine_fk\\\\nprint(\\\\\\\"\\\\\\\\nMCH-WGT-hips current parent:\\\\\\\", bones[\\\\\\\"MCH-WGT-hips\\\\\\\"].parent.name)\\\\n\\\",\\\"user_prompt\\\":\\\"check MCH-WGT-hips\\\"}\"," - }, - { - "lineNumber": 9386, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: MCH-spine.001: COPY_TRANSFORMS -> hips\\\\nMCH-spine: COPY_TRANSFORMS -> hips\\\\n\\\\nMCH-WGT-hips current parent: spine_fk\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9417, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\n# Check vertex groups that might use MCH-WGT-hips\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nfor obj in bpy.data.objects:\\\\n if obj.type == 'MESH' and hasattr(obj.data, 'vertex_groups'):\\\\n for vg in obj.data.vertex_groups:\\\\n if vg.name == arm.data.bones.get(vg.name) and 'hips' in vg.name:\\\\n pass\\\\n # Check armature modifier\\\\n for mod in obj.modifiers:\\\\n if mod.type == 'ARMATURE' and mod.object == arm:\\\\n print(f\\\\\\\"{obj.name} uses armature\\\\\\\")\\\\n\\\",\\\"user_prompt\\\":\\\"check armature usage\\\"}\"," - }, - { - "lineNumber": 9465, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbpy.context.view_layer.objects.active = arm\\\\nbpy.ops.object.mode_set(mode='EDIT')\\\\n\\\\neb = arm.data.edit_bones\\\\n\\\\n# MCH-WGT-hips is under spine_fk - when spine_fk rotates, it rotates (drives hips deformation)\\\\n# Move it to MCH-spine.001 so it follows hips only, not spine_fk rotation\\\\neb[\\\\\\\"MCH-WGT-hips\\\\\\\"].parent = eb[\\\\\\\"MCH-spine.001\\\\\\\"]\\\\n\\\\nbpy.ops.object.mode_set(mode='POSE')\\\\nprint(\\\\\\\"MCH-WGT-hips moved from spine_fk to MCH-spine.001 - now follows hips only\\\\\\\")\\\\n\\\",\\\"user_prompt\\\":\\\"move MCH-WGT-hips off spine_fk to MCH-spine.001\\\"}\"," - }, - { - "lineNumber": 9482, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: MCH-WGT-hips moved from spine_fk to MCH-spine.001 - now follows hips only\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9513, - "content": " \"parameters\": \"{\\\"code\\\":\\\"\\\\nimport bpy\\\\n\\\\narm = bpy.data.objects[\\\\\\\"Vanessa\\\\\\\"]\\\\nbones = arm.data.bones\\\\n\\\\n# Verify: tweak_spine (pelvis/ORG-spine) should NOT be under spine_fk\\\\nprint(\\\\\\\"tweak_spine parent:\\\\\\\", bones[\\\\\\\"tweak_spine\\\\\\\"].parent.name)\\\\nprint(\\\\\\\"spine_fk children:\\\\\\\", [c.name for c in bones[\\\\\\\"spine_fk\\\\\\\"].children])\\\\nprint(\\\\\\\"MCH-spine.001 children:\\\\\\\", [c.name for c in bones[\\\\\\\"MCH-spine.001\\\\\\\"].children])\\\\n\\\",\\\"user_prompt\\\":\\\"verify tweak_spine and MCH-WGT-hips\\\"}\"," - }, - { - "lineNumber": 9530, - "content": " \"result\": \"{\\\"content\\\":[{\\\"type\\\":\\\"text\\\",\\\"text\\\":\\\"Code executed successfully: tweak_spine parent: MCH-spine.001\\\\nspine_fk children: ['MCH-spine', 'spine_fk.001']\\\\nMCH-spine.001 children: ['spine_fk', 'MCH-WGT-hips', 'tweak_spine']\\\\n\\\"}]}\"" - }, - { - "lineNumber": 9544, - "content": "`MCH-WGT-hips` is now parented to **MCH-spine.001** instead of `spine_fk`, so it follows the hips control and no longer rotates with `spine_fk`." - }, - { - "lineNumber": 9548, - "content": "- **MCH-WGT-hips** → parent: MCH-spine.001 " - }, - { - "lineNumber": 9551, - "content": "`spine_fk` no longer drives the pelvis or hips; it only affects the spine chain." - } - ] - }, - { - "file": ".\\.specstory\\history\\2026-01-04_00-03Z-staged-files-lfs-tracking.md", - "matches": [ - { - "lineNumber": 579, - "content": "Assets/Blends/Env/textures/Atrium/MAT_DriveThruMenu_ElChips/TEX_DriveThruMenu_ElChips_BaseColor.png|.png" - }, - { - "lineNumber": 580, - "content": "Assets/Blends/Env/textures/Atrium/MAT_DriveThruMenu_ElChips/TEX_DriveThruMenu_ElChips_Normal.png|.png" - }, - { - "lineNumber": 581, - "content": "Assets/Blends/Env/textures/Atrium/MAT_DriveThruMenu_ElChips/TEX_DriveThruMenu_ElChips_OcclusionRoughnessMetallic.png|.png" - }, - { - "lineNumber": 913, - "content": "Assets/Blends/Env/textures/Atrium/Material/TEX_ElChips_Logo.png|.png" - } - ] - } - ], - "totalLines": 45, - "totalMatchedLines": 45 - } - } + "isPruned": true, + "pattern": "hips|MCH-WGT-hips", + "path": "D:\\2025-12-28 ytshorts gigaproj", + "outputMode": "content", + "totalFiles": 2, + "totalMatches": 45, + "topFiles": [ + { + "uri": ".\\.specstory\\history\\2026-01-13_05-41Z-gimble-live-animation-in-b5-0.md", + "matchCount": 41 + }, + { + "uri": ".\\.specstory\\history\\2026-01-04_00-03Z-staged-files-lfs-tracking.md", + "matchCount": 4 } - } + ] } ``` Status: **completed** @@ -9467,8 +9271,6 @@ Status: **completed** - - --- @@ -9515,8 +9317,6 @@ Status: **completed** - - --- @@ -9561,7 +9361,6 @@ Status: **completed** --- - Updated the rig so that: 1. **spine_fk** is parented to **torso** instead of MCH-spine.001 (which copies hips), so the spine FK chain is no longer driven by hips. @@ -9571,3 +9370,1299 @@ Spine FK and hips are now separate controls under torso. --- +_**User**_ + +Use blender-mcp again. Back to Burntrap. I think there's a pretty egregious dependency cycle on this rig somewhere, but it's not detected by the console as far as I can see. This is the source blend. In my animation blend, I used dynamic parent (creates child of constraints) to parent his root to an object that's controlled by an armature, then I moved that armature object. The result was the root rotating along the axis that I was moving the armature object along, almost as if it was calculating physics drag. Similar to some of our other dependency cycles, but a bit different. My CPU util also spiked to ~80%, so something must be going on there. + +--- + +_**Agent (model default, mode Agent)**_ + +
Thought Process + +The user is asking me to use Blender MCP to investigate a dependency cycle on a rig called "Burntrap". They're working with a source blend file. The symptoms are: +1. They used dynamic parent (child of constraint) to parent Burntrap's root to an object controlled by an armature +2. When they moved that armature object, the root rotated along the axis of movement - like "physics drag" +3. CPU spiked to ~80% +4. Suggests a dependency cycle that isn't detected by the console + +I need to: +1. Get scene info to find the Burntrap armature and understand the rig +2. Look for dependency cycles - constraints that might create circular dependencies +3. Check for Child Of constraints and how they chain +4. Look at what might cause the root to rotate when a parent object moves (could be a cycle where root affects something that affects the parent that affects the root) + +Let me start by getting the Blender scene info. The user said "this is the source blend" - so they might have the Burntrap blend file open in Blender. I'll use the MCP tools to inspect the scene. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-get_scene_info** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "get_scene_info", + "parameters": "{\"user_prompt\":\"Burntrap rig dependency cycle investigation - root rotating with dynamic parent, CPU spike\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"{\\n \\\"name\\\": \\\"Scene\\\",\\n \\\"object_count\\\": 45,\\n \\\"objects\\\": [\\n {\\n \\\"name\\\": \\\"Burntrap-RIG\\\",\\n \\\"type\\\": \\\"ARMATURE\\\",\\n \\\"location\\\": [\\n 0.0,\\n 0.0,\\n 0.0\\n ]\\n },\\n {\\n \\\"name\\\": \\\"Eye.001\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"Gear\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT.Hanger\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_chest\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eye.L\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyelid\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyelid.001\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyes\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_foot_heel_ik.R\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n }\\n ],\\n \\\"materials_count\\\": 8\\n}\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +The scene has Burntrap-RIG armature. Let me get more detail on the armature - bone hierarchy, constraints (especially Child Of / COPY_TRANSFORMS), and look for cycles. I'll run Python in Blender to map constraints and parent chains. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif not arm or arm.type != 'ARMATURE':\\n print(\\\"Burntrap-RIG armature not found\\\")\\nelse:\\n bones = arm.data.bones\\n pb = arm.pose.bones\\n # Root bone\\n root = bones.get(\\\"root\\\") or bones.get(\\\"Root\\\") or list(bones)[0]\\n root_name = root.name if root else \\\"?\\\"\\n print(\\\"Root bone:\\\", root_name)\\n print(\\\"Total bones:\\\", len(bones))\\n # All constraints that reference another bone (potential cycle sources)\\n print(\\\"\\\\n--- Constraints with subtargets (cycle candidates) ---\\\")\\n for bname, pose_b in pb.items():\\n for c in pose_b.constraints:\\n if getattr(c, 'subtarget', None):\\n tgt = getattr(c, 'target', None)\\n tgt_name = tgt.name if tgt else \\\"\\\"\\n print(f\\\" {bname} <- {c.type}: target={tgt_name}, subtarget={c.subtarget}\\\")\\n\",\"user_prompt\":\"Burntrap constraints and root bone\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Root bone: Root\\nTotal bones: 130\\n\\n--- Constraints with subtargets (cycle candidates) ---\\n IK_Wrist_L <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=FK_Wrist_L\\n L_Wrist_jnt <- COPY_LOCATION: target=Burntrap-RIG, subtarget=L_Elbow_jnt\\n L_PinkyB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_PinkyA_jnt\\n L_PinkyC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_PinkyB_jnt\\n L_MiddleB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_MiddleA_jnt\\n L_MiddleC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_MiddleB_jnt\\n L_IndexB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_IndexA_jnt\\n L_IndexC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_IndexB_jnt\\n L_ThumbB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_ThumbA_jnt\\n L_ThumbC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_ThumbB_jnt\\n L_RingB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_RingA_jnt\\n L_RingC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_RingB_jnt\\n IK_Wrist_R <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=FK_Wrist_R\\n R_Wrist_jnt <- COPY_LOCATION: target=Burntrap-RIG, subtarget=R_Elbow_jnt\\n R_PinkyB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_PinkyA_jnt\\n R_PinkyC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_PinkyB_jnt\\n R_MiddleB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_MiddleA_jnt\\n R_MiddleC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_MiddleB_jnt\\n R_IndexB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_IndexA_jnt\\n R_IndexC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_IndexB_jnt\\n R_RingB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_RingA_jnt\\n R_RingC_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_RingB_jnt\\n R_ThumbB_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_ThumbA_jnt\\n IK_Ankle_L <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=FK_Ankle_L\\n L_Toe_jnt.002 <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_Knee_jnt.001\\n L_Toe_jnt.001 <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_Knee_jnt.001\\n L_Ankle_jnt <- COPY_LOCATION: target=Burntrap-RIG, subtarget=L_Knee_jnt\\n L_Toe_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_Toe_jnt.003\\n L_Toe_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=L_Toe_FK\\n L_Toe_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_Toe\\n IK_Ankle_R <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=FK_Ankle_R\\n R_Toe_jnt.002 <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_Knee_jnt.001\\n R_Toe_jnt.001 <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_Knee_jnt.001\\n R_Ankle_jnt <- COPY_LOCATION: target=Burntrap-RIG, subtarget=R_Knee_jnt\\n R_Toe_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_Toe_jnt.003\\n R_Toe_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=R_Toe_FK\\n R_Toe_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_Toe\\n L_UpperLeg_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=L_UpperLeg_FK\\n L_Knee_jnt <- IK: target=Burntrap-RIG, subtarget=L_Ankle_jntrOLL\\n R_UpperLeg_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=R_UpperLeg_FK\\n R_Knee_jnt <- IK: target=Burntrap-RIG, subtarget=R_Ankle_jntrOLL\\n Spine_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=Spine_jnt.001\\n Spine1_jnt <- IK: target=Burntrap-RIG, subtarget=Spine1_jnt.002\\n Neck_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=Neck_jnt.001\\n L_Eye_jnt <- IK: target=Burntrap-RIG, subtarget=Eyecontroller_L\\n R_Eye_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=R_Eye1_jnt\\n L_Eye1_jnt <- COPY_ROTATION: target=Burntrap-RIG, subtarget=L_Eye_jnt\\n R_Eye1_jnt <- IK: target=Burntrap-RIG, subtarget=Eyecontroller_R\\n Mask_jnt1 <- COPY_ROTATION: target=Burntrap-RIG, subtarget=Mask_jnt\\n Mask_jntNEW <- DAMPED_TRACK: target=Burntrap-RIG, subtarget=Mask_jnt\\n NeckSpine2_jnt <- DAMPED_TRACK: target=Burntrap-RIG, subtarget=NeckSpine1_jnt\\n NeckSpine8_jnt <- IK: target=Burntrap-RIG, subtarget=Root_jnt\\n L_Shoulder_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=L_Shoulder_FK\\n L_Elbow_jnt <- IK: target=Burntrap-RIG, subtarget=IK_Wrist_L\\n R_Shoulder_jnt <- COPY_TRANSFORMS: target=Burntrap-RIG, subtarget=R_Shoulder_FK\\n R_Elbow_jnt <- IK: target=Burntrap-RIG, subtarget=IK_Wrist_R\\n Spine1_jnt.001 <- STRETCH_TO: target=Burntrap-RIG, subtarget=Spine_jnt.001\\n NeckSpine <- COPY_LOCATION: target=Burntrap-RIG, subtarget=Spine_jnt\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +I see several interesting things. Let me look for cycles: + +1. **Spine1_jnt** has IK targeting **Spine1_jnt.002** +2. **Spine1_jnt.001** has STRETCH_TO targeting **Spine_jnt.001** +3. **NeckSpine8_jnt** has IK targeting **Root_jnt** - so spine IK targets Root! That could create a cycle: Root -> ... -> NeckSpine8_jnt -> IK -> Root_jnt. If Root_jnt is near or part of the root chain, that's a cycle. +4. **NeckSpine** has COPY_LOCATION targeting **Spine_jnt** +5. **Spine_jnt** has COPY_ROTATION targeting **Spine_jnt.001** + +I need to map the parent hierarchy and see if any constraint creates A -> B -> ... -> A. Especially: +- Root and Root_jnt relationship +- Spine1_jnt, Spine1_jnt.001, Spine1_jnt.002 chain +- NeckSpine8_jnt IK to Root_jnt + +Let me get the bone hierarchy from Root and find Root_jnt, and trace constraint chains. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# Hierarchy from Root\\ndef ancestors(b):\\n out = []\\n p = b.parent\\n while p:\\n out.append(p.name)\\n p = p.parent\\n return out\\n\\ndef descendants(b, depth=0, maxdepth=5):\\n if depth > maxdepth: return []\\n out = [b.name]\\n for c in b.children:\\n out.extend(descendants(c, depth+1, maxdepth))\\n return out\\n\\nroot = bones.get(\\\"Root\\\")\\nroot_jnt = bones.get(\\\"Root_jnt\\\")\\nprint(\\\"Root parent:\\\", root.parent.name if root and root.parent else None)\\nprint(\\\"Root ancestors:\\\", ancestors(root) if root else [])\\nprint(\\\"\\\\nRoot_jnt parent:\\\", root_jnt.parent.name if root_jnt and root_jnt.parent else None)\\nprint(\\\"Root_jnt ancestors:\\\", ancestors(root_jnt) if root_jnt else [])\\nprint(\\\"Root_jnt descendants (first 15):\\\", (descendants(root_jnt, maxdepth=3)[:15] if root_jnt else []))\\n\\n# Spine1 chain - IK target\\nprint(\\\"\\\\n--- Spine1 chain ---\\\")\\nfor n in [\\\"Spine1_jnt\\\", \\\"Spine1_jnt.001\\\", \\\"Spine1_jnt.002\\\"]:\\n b = bones.get(n)\\n if b:\\n print(f\\\"{n}: parent={b.parent.name if b.parent else None}, ancestors to Root: {'Root' in ancestors(b)}\\\")\\n\\n# NeckSpine8_jnt IK targets Root_jnt - where is NeckSpine8 in hierarchy?\\nneck8 = bones.get(\\\"NeckSpine8_jnt\\\")\\nprint(\\\"\\\\nNeckSpine8_jnt parent:\\\", neck8.parent.name if neck8 and neck8.parent else None)\\nprint(\\\"NeckSpine8_jnt ancestors:\\\", ancestors(neck8)[:10] if neck8 else [])\\n\",\"user_prompt\":\"Root and Root_jnt hierarchy, spine and neck chain\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Root parent: None\\nRoot ancestors: []\\n\\nRoot_jnt parent: Root_jnt.001\\nRoot_jnt ancestors: ['Root_jnt.001', 'Root']\\nRoot_jnt descendants (first 15): ['Root_jnt', 'L_UpperLeg_jnt', 'L_Knee_jnt', 'L_Knee_Jiggle_jnt', 'L_UpperLeg_Jiggle_jnt', 'R_UpperLeg_jnt', 'R_Knee_jnt', 'R_Knee_Jiggle_jnt', 'R_UpperLeg_Jiggle_jnt', 'Root_Jiggle_jnt', 'L_UpperLeg_FK', 'L_Knee_FK', 'FK_Ankle_L', 'R_UpperLeg_FK', 'R_Knee_FK']\\n\\n--- Spine1 chain ---\\nSpine1_jnt: parent=Root_jnt.001, ancestors to Root: True\\nSpine1_jnt.001: parent=Root_jnt.001, ancestors to Root: True\\nSpine1_jnt.002: parent=Root_jnt.001, ancestors to Root: True\\n\\nNeckSpine8_jnt parent: NeckSpine7_jnt\\nNeckSpine8_jnt ancestors: ['NeckSpine7_jnt', 'NeckSpine6_jnt', 'NeckSpine5_jnt', 'NeckSpine4_jnt', 'NeckSpine3_jnt', 'NeckSpine2_jnt', 'NeckSpine1_jnt', 'Neck_jnt', 'Spine1_jnt', 'Root_jnt.001']\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So we have: +- Root (no parent) -> Root_jnt.001 -> Root_jnt (and Spine1_jnt, Spine1_jnt.001, Spine1_jnt.002 are under Root_jnt.001) +- NeckSpine8_jnt has ancestors: ... NeckSpine1_jnt, Neck_jnt, Spine1_jnt, Root_jnt.001 + +So the chain is: Root -> Root_jnt.001 -> Spine1_jnt -> Neck_jnt -> NeckSpine1_jnt -> ... -> NeckSpine8_jnt + +NeckSpine8_jnt has IK targeting **Root_jnt**. So we have: +- Root_jnt is a descendant of Root +- NeckSpine8_jnt is a descendant of Spine1_jnt, which is under Root_jnt.001 +- Root_jnt.001's children include Root_jnt and Spine1_jnt + +So hierarchy: Root -> Root_jnt.001 -> [Root_jnt, Spine1_jnt, ...]. So Root_jnt and Spine1_jnt are siblings. Spine1_jnt -> ... -> NeckSpine8_jnt. And NeckSpine8_jnt has IK target Root_jnt. So the IK chain is: Spine1_jnt (start) ... NeckSpine8_jnt (end) with target Root_jnt. That means the spine/neck chain is trying to reach Root_jnt. So when you move the rig, the IK solver pulls the chain toward Root_jnt. Root_jnt is under Root. So that's not necessarily a cycle unless something else makes Root depend on NeckSpine8_jnt or the IK result. + +Let me check: does Root have any constraints? Or does any bone in the chain copy from something that eventually depends on Root? +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# Root and Root_jnt constraints\\nfor name in [\\\"Root\\\", \\\"Root_jnt\\\", \\\"Root_jnt.001\\\", \\\"Spine1_jnt\\\", \\\"Spine1_jnt.001\\\", \\\"Spine1_jnt.002\\\"]:\\n if name in pb:\\n b = pb[name]\\n print(f\\\"{name}:\\\")\\n for c in b.constraints:\\n print(f\\\" {c.type}: subtarget={getattr(c, 'subtarget', '')}\\\")\\n if not b.constraints:\\n print(\\\" (no constraints)\\\")\\n print()\\n\\n# Build dependency graph: for each bone, who does it depend on (via constraints)?\\n# Then check if Root is in a cycle (Root -> X -> ... -> Root)\\ndef get_constraint_targets(pose_bone):\\n deps = []\\n for c in pose_bone.constraints:\\n if not getattr(c, 'target', None): continue\\n if c.target != arm: continue\\n sub = getattr(c, 'subtarget', None)\\n if sub and sub in bones:\\n deps.append(sub)\\n return deps\\n\\n# Find any bone that depends on Root (directly or indirectly) while Root or its ancestors depend on that bone\\nprint(\\\"--- Who does Root depend on? ---\\\")\\nprint(\\\"Root constraint deps:\\\", get_constraint_targets(pb[\\\"Root\\\"]))\\n\\nprint(\\\"\\\\n--- Who depends on Root or Root_jnt? ---\\\")\\nfor name, pose_b in pb.items():\\n deps = get_constraint_targets(pose_b)\\n if \\\"Root\\\" in deps or \\\"Root_jnt\\\" in deps:\\n print(f\\\" {name} copies/targets Root or Root_jnt\\\")\\n\",\"user_prompt\":\"Root constraints and who depends on Root\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Root:\\n (no constraints)\\n\\nRoot_jnt:\\n (no constraints)\\n\\nRoot_jnt.001:\\n (no constraints)\\n\\nSpine1_jnt:\\n IK: subtarget=Spine1_jnt.002\\n\\nSpine1_jnt.001:\\n STRETCH_TO: subtarget=Spine_jnt.001\\n\\nSpine1_jnt.002:\\n (no constraints)\\n\\n--- Who does Root depend on? ---\\nRoot constraint deps: []\\n\\n--- Who depends on Root or Root_jnt? ---\\n NeckSpine8_jnt copies/targets Root or Root_jnt\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So NeckSpine8_jnt has an IK that targets Root_jnt. The IK chain would be from Spine1_jnt (parent of Neck_jnt...) to NeckSpine8_jnt, and the target is Root_jnt. So the neck chain tries to reach Root_jnt. Root_jnt is BELOW Spine1_jnt in the hierarchy (Root -> Root_jnt.001 -> Root_jnt, Spine1_jnt). So the IK is from Spine1_jnt to NeckSpine8_jnt with target Root_jnt. That's a bit odd - the target is behind the chain start. That could cause weird behavior. + +Let me check Spine1_jnt.001: STRETCH_TO subtarget=Spine_jnt.001. So Spine1_jnt.001 stretches toward Spine_jnt.001. Where is Spine_jnt.001 in the hierarchy? And Spine_jnt has COPY_ROTATION from Spine_jnt.001. So there might be a cycle: Spine_jnt.001 -> (COPY_ROTATION source?) or Spine1_jnt.001 STRETCH_TO Spine_jnt.001. Let me map Spine_jnt and Spine_jnt.001. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# Spine_jnt and Spine_jnt.001 - relationship and constraints\\nfor n in [\\\"Spine_jnt\\\", \\\"Spine_jnt.001\\\", \\\"Spine1_jnt\\\", \\\"Spine1_jnt.001\\\", \\\"Spine1_jnt.002\\\"]:\\n b = bones.get(n)\\n p = pb.get(n)\\n if b and p:\\n par = b.parent.name if b.parent else None\\n deps = [c.subtarget for c in p.constraints if getattr(c, 'subtarget', None)]\\n print(f\\\"{n}: parent={par}, constraint_targets={deps}\\\")\\n\\n# Full chain: Spine1_jnt.001 STRETCH_TO Spine_jnt.001; Spine_jnt COPY_ROTATION Spine_jnt.001\\n# So Spine_jnt depends on Spine_jnt.001. Where is Spine_jnt in hierarchy?\\nspine_jnt = bones.get(\\\"Spine_jnt\\\")\\nspine_jnt_001 = bones.get(\\\"Spine_jnt.001\\\")\\ndef path_to_root(b):\\n out = []\\n while b:\\n out.append(b.name)\\n b = b.parent\\n return out\\nprint(\\\"\\\\nSpine_jnt path to root:\\\", path_to_root(spine_jnt)[:8] if spine_jnt else [])\\nprint(\\\"Spine_jnt.001 path to root:\\\", path_to_root(spine_jnt_001)[:8] if spine_jnt_001 else [])\\n\\n# Child Of constraints (external - on objects)\\nprint(\\\"\\\\n--- Child Of on armature or objects ---\\\")\\nfor obj in bpy.data.objects:\\n if obj.type == 'ARMATURE' and obj.name == \\\"Burntrap-RIG\\\":\\n continue\\n for c in obj.constraints:\\n if c.type == 'CHILD_OF':\\n t = getattr(c, 'target', None)\\n sub = getattr(c, 'subtarget', '')\\n print(f\\\" {obj.name}: CHILD_OF target={t.name if t else None}, subtarget={sub}\\\")\\n\",\"user_prompt\":\"Spine_jnt chain and Child Of constraints\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Spine_jnt: parent=Root_jnt.001, constraint_targets=['Spine_jnt.001']\\nSpine_jnt.001: parent=Root_jnt.001, constraint_targets=[]\\nSpine1_jnt: parent=Root_jnt.001, constraint_targets=['Spine1_jnt.002']\\nSpine1_jnt.001: parent=Root_jnt.001, constraint_targets=['Spine_jnt.001']\\nSpine1_jnt.002: parent=Root_jnt.001, constraint_targets=[]\\n\\nSpine_jnt path to root: ['Spine_jnt', 'Root_jnt.001', 'Root']\\nSpine_jnt.001 path to root: ['Spine_jnt.001', 'Root_jnt.001', 'Root']\\n\\n--- Child Of on armature or objects ---\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So we have: +- Spine1_jnt has IK targeting Spine1_jnt.002. So the IK chain is Spine1_jnt -> ... -> Spine1_jnt.002 (end effector). So the chain goes from Spine1_jnt to Spine1_jnt.002. But wait - Spine1_jnt.001 and Spine1_jnt.002 have parent Root_jnt.001. So Spine1_jnt, Spine1_jnt.001, Spine1_jnt.002 are siblings! So the IK chain Spine1_jnt with target Spine1_jnt.002 - the chain would be Spine1_jnt -> Neck_jnt -> ... -> and the target is Spine1_jnt.002. So the pole or target might be Spine1_jnt.002. So the IK solver solves from Spine1_jnt (root of chain) to reach Spine1_jnt.002. That means the chain between them (Neck_jnt, NeckSpine1-8) is being solved to put the end at Spine1_jnt.002. So Spine1_jnt.002 is the target. And Spine1_jnt.001 has STRETCH_TO Spine_jnt.001. So Spine1_jnt.001's transform depends on Spine_jnt.001. Spine_jnt has COPY_ROTATION from Spine_jnt.001. So Spine_jnt depends on Spine_jnt.001. + +Could there be a cycle? Spine_jnt.001 has no constraints. Spine_jnt copies from Spine_jnt.001. Spine1_jnt.001 stretches to Spine_jnt.001. So Spine1_jnt.001 depends on Spine_jnt.001. Does Spine_jnt.001 depend on anything that eventually depends on Spine1_jnt.001? Spine_jnt.001 has no constraints. So no cycle there. + +The user said they added Child Of on the root (of the character) to an object controlled by an armature, then moved that armature. So in the animation file, the Burntrap armature's Root (or the armature object?) has a Child Of to another object. That object is controlled by an armature. So we have: Armature A (other) -> controls -> Object B. Burntrap armature has Child Of constraint to Object B (or to a bone of Armature A?). When they move Armature A, the root rotates with "physics drag" and CPU spikes. So the cycle might be: Armature A moves -> Object B moves (bone or object) -> Child Of makes Burntrap root follow -> Burntrap rig evaluates -> something in Burntrap rig affects Object B or Armature A? That would require something in the scene to drive the parent. So the cycle could be in the animation file. But the user said "this is the source blend" - so the source blend might not have the Child Of. The cycle could be entirely within the Burntrap rig, causing unstable evaluation when the root is constrained. So when the root gets a Child Of, the evaluation order might become: 1) parent object updates, 2) Child Of applies to root, 3) rest of rig evaluates from root. If somewhere in the rig a bone copies or is driven by something that ends up depending on the root's world transform (e.g. through the parent object), we get a cycle. So I need to find: does any bone in the rig depend on world space or on something that could be affected by the root? For example, NeckSpine8_jnt has IK target Root_jnt. So the IK tries to put NeckSpine8 at Root_jnt. When the root moves (via Child Of), Root_jnt moves. So the IK target moves. The IK chain (Spine1_jnt -> ... -> NeckSpine8_jnt) then re-solves. So the spine/neck moves. That could feed back if something in the chain then drives the root. Does anything drive the root? Root has no constraints. So in the source rig, nothing drives Root. But in the user's animation file, Root (or the armature) has Child Of to an object. So the flow is: Object (parent) -> Child Of -> Root. So the parent object drives Root. The parent object is controlled by an armature. So when they move that armature, the object moves. So Root moves. Then the whole rig evaluates. The "physics drag" and rotation could be: if the object that has Child Of is a bone (subtarget), then the bone's transform is in armature space. When the armature moves, the bone's world position changes. Child Of makes the root follow that bone. So root world = bone world. Then the rig evaluates. If any part of the rig (e.g. IK or COPY) uses world space or a bone that ends up depending on the armature object's transform, we could get feedback. Actually, the user said "root rotating along the axis that I was moving the armature object along" - so when they move the armature OBJECT (not a bone), the root rotates. That suggests the root is getting rotation from the movement. That could happen if: 1) Child Of is set to the armature object (not a bone), so the root gets the object's transform. When you move the object, the root follows. But then "rotating along the axis" - maybe the root is rotating when they translate? That could be a gimbal or evaluation order issue. 2) Or there's a cycle: moving the object updates the root -> rig evaluates -> something in the rig writes back to the object or a bone that affects the object -> object moves again -> ... So we need to find if any bone has a constraint that targets something outside the armature (another object or the armature object itself). Let me check for constraints with target != Burntrap-RIG. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\npb = arm.pose.bones\\n\\n# Constraints targeting another object (external deps)\\nprint(\\\"--- Constraints targeting other objects ---\\\")\\nfor name, b in pb.items():\\n for c in b.constraints:\\n t = getattr(c, 'target', None)\\n if t and t != arm:\\n print(f\\\" {name}: {c.type} target={t.name}, subtarget={getattr(c, 'subtarget', '')}\\\")\\n\\n# IK chains: list all IK constraints and their chain\\nprint(\\\"\\\\n--- IK constraints (potential cycle with target) ---\\\")\\nfor name, b in pb.items():\\n for c in b.constraints:\\n if c.type == 'IK':\\n sub = getattr(c, 'subtarget', '')\\n chain_len = getattr(c, 'chain_length', 0)\\n print(f\\\" {name}: IK target={sub}, chain_length={chain_len}\\\")\\n\\n# Spine1_jnt.001 STRETCH_TO Spine_jnt.001 - is there COPY back?\\n# Spine_jnt COPY_ROTATION Spine_jnt.001. So Spine_jnt is in the hierarchy under Root.\\n# When root moves, Spine_jnt moves (it's a descendant). Spine_jnt gets rotation from Spine_jnt.001.\\n# Spine_jnt.001 is also under Root. So when root moves, both move. No cycle there.\\n# Unless: Spine1_jnt.001 STRETCH_TO Spine_jnt.001. Spine1_jnt.001 is under Root_jnt.001.\\n# So Spine1_jnt.001's position is computed by STRETCH_TO Spine_jnt.001. So it depends on Spine_jnt.001.\\n# Spine_jnt.001 has no constraints. So evaluation: Spine_jnt.001 first (from hierarchy), then Spine1_jnt.001 (STRETCH_TO), etc. No cycle.\\n\\n# Check COPY_LOCATION / COPY_TRANSFORMS that might create feedback\\nprint(\\\"\\\\n--- COPY_LOCATION / COPY_TRANSFORMS (same-armature) ---\\\")\\nfor name, b in pb.items():\\n for c in b.constraints:\\n if c.type in ('COPY_LOCATION', 'COPY_TRANSFORMS') and getattr(c, 'target', None) == arm:\\n sub = getattr(c, 'subtarget', '')\\n if sub:\\n print(f\\\" {name} <- {sub} ({c.type})\\\")\\n\",\"user_prompt\":\"external targets and IK chains\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: --- Constraints targeting other objects ---\\n\\n--- IK constraints (potential cycle with target) ---\\n L_Knee_jnt: IK target=L_Ankle_jntrOLL, chain_length=0\\n R_Knee_jnt: IK target=R_Ankle_jntrOLL, chain_length=0\\n Spine1_jnt: IK target=Spine1_jnt.002, chain_length=0\\n L_Eye_jnt: IK target=Eyecontroller_L, chain_length=0\\n R_Eye1_jnt: IK target=Eyecontroller_R, chain_length=0\\n NeckSpine8_jnt: IK target=Root_jnt, chain_length=0\\n L_Elbow_jnt: IK target=IK_Wrist_L, chain_length=0\\n R_Elbow_jnt: IK target=IK_Wrist_R, chain_length=0\\n\\n--- COPY_LOCATION / COPY_TRANSFORMS (same-armature) ---\\n IK_Wrist_L <- FK_Wrist_L (COPY_TRANSFORMS)\\n L_Wrist_jnt <- L_Elbow_jnt (COPY_LOCATION)\\n IK_Wrist_R <- FK_Wrist_R (COPY_TRANSFORMS)\\n R_Wrist_jnt <- R_Elbow_jnt (COPY_LOCATION)\\n IK_Ankle_L <- FK_Ankle_L (COPY_TRANSFORMS)\\n L_Ankle_jnt <- L_Knee_jnt (COPY_LOCATION)\\n L_Toe_jnt <- L_Toe_FK (COPY_TRANSFORMS)\\n IK_Ankle_R <- FK_Ankle_R (COPY_TRANSFORMS)\\n R_Ankle_jnt <- R_Knee_jnt (COPY_LOCATION)\\n R_Toe_jnt <- R_Toe_FK (COPY_TRANSFORMS)\\n L_UpperLeg_jnt <- L_UpperLeg_FK (COPY_TRANSFORMS)\\n R_UpperLeg_jnt <- R_UpperLeg_FK (COPY_TRANSFORMS)\\n L_Shoulder_jnt <- L_Shoulder_FK (COPY_TRANSFORMS)\\n R_Shoulder_jnt <- R_Shoulder_FK (COPY_TRANSFORMS)\\n NeckSpine <- Spine_jnt (COPY_LOCATION)\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +NeckSpine has COPY_LOCATION from Spine_jnt. So NeckSpine's location comes from Spine_jnt. Where is NeckSpine in the hierarchy? If NeckSpine is an ancestor of Spine_jnt, that would be a cycle (NeckSpine copies from Spine_jnt, but Spine_jnt is under NeckSpine?). Let me check NeckSpine's parent and where it sits relative to Spine_jnt. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# Full hierarchy from Root\\ndef tree(b, indent=0, maxdepth=4):\\n if indent > maxdepth: return\\n kids = b.children\\n cons = [c.type for c in pb[b.name].constraints] if b.name in pb else []\\n print(\\\" \\\" * indent + f\\\"{b.name} {cons}\\\")\\n for c in kids:\\n tree(c, indent + 1, maxdepth)\\n\\nroot = bones.get(\\\"Root\\\")\\nprint(\\\"--- Hierarchy from Root (depth 4) ---\\\")\\nif root:\\n tree(root, maxdepth=4)\\n\\n# Check: does Spine1_jnt.002 have any constraint that could point back up?\\nprint(\\\"\\\\n--- Spine1_jnt.002 constraints ---\\\")\\nb = pb.get(\\\"Spine1_jnt.002\\\")\\nif b:\\n for c in b.constraints:\\n print(f\\\" {c.type}: {getattr(c, 'subtarget', '')}\\\")\\n\\n# Critical: IK chain from Spine1_jnt to Spine1_jnt.002 - but Spine1_jnt and Spine1_jnt.002 are SIBLINGS (both parent Root_jnt.001)\\n# So the IK chain is Spine1_jnt -> ... -> ? (end effector). The target is Spine1_jnt.002.\\n# So the chain must be Spine1_jnt -> Neck_jnt -> ... -> and the last bone in the chain is the end effector. The target is Spine1_jnt.002.\\n# So the end effector is NOT Spine1_jnt.002 - the target is Spine1_jnt.002. So the chain tries to put the end effector at the position of Spine1_jnt.002. That's valid.\\n# But Spine1_jnt.001 has STRETCH_TO Spine_jnt.001. And Spine1_jnt.001 and Spine1_jnt.002 are siblings. So the chain might be Spine1_jnt -> Spine1_jnt.001? No - Spine1_jnt.001 parent is Root_jnt.001. So Spine1_jnt -> Neck_jnt -> NeckSpine1 -> ... -> NeckSpine8. So Spine1_jnt.001 is not in that chain. So we have two separate things: one is the spine/neck chain (Spine1_jnt to NeckSpine8), and Spine1_jnt.001 is a separate bone that STRETCH_TO Spine_jnt.001.\\n</think>\\n\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Error executing code: Communication error with Blender: Code execution error: invalid syntax (<string>, line 34)\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Syntax error - probably the "tree" recursive call. Let me simplify. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# NeckSpine - where is it, what does it copy?\\nneck = bones.get(\\\"NeckSpine\\\")\\nspine_jnt = bones.get(\\\"Spine_jnt\\\")\\nprint(\\\"NeckSpine parent:\\\", neck.parent.name if neck and neck.parent else None)\\nprint(\\\"Spine_jnt parent:\\\", spine_jnt.parent.name if spine_jnt and spine_jnt.parent else None)\\n# Is NeckSpine an ancestor of Spine_jnt?\\ndef path_up(b):\\n out = []\\n while b:\\n out.append(b.name)\\n b = b.parent\\n return out\\nprint(\\\"NeckSpine path to root:\\\", path_up(neck)[:6] if neck else [])\\nprint(\\\"Spine_jnt path to root:\\\", path_up(spine_jnt)[:6] if spine_jnt else [])\\n\\n# So NeckSpine COPY_LOCATION Spine_jnt. NeckSpine must be evaluated after Spine_jnt.\\n# If NeckSpine is a descendant of Spine_jnt, we have a cycle (Spine_jnt -> ... -> NeckSpine -> COPY Spine_jnt).\\nif neck and spine_jnt:\\n spine_ancestors = set(path_up(spine_jnt))\\n if neck.name in spine_ancestors:\\n print(\\\"CYCLE: NeckSpine is ancestor of Spine_jnt but NeckSpine copies Spine_jnt!\\\")\\n elif spine_jnt.name in path_up(neck):\\n print(\\\"OK: Spine_jnt is ancestor of NeckSpine (correct order)\\\")\\n else:\\n print(\\\"NeckSpine and Spine_jnt in different branches\\\")\\n\\n# List Root_jnt.001 children\\nr1 = bones.get(\\\"Root_jnt.001\\\")\\nprint(\\\"\\\\nRoot_jnt.001 children:\\\", [c.name for c in r1.children] if r1 else [])\\n\",\"user_prompt\":\"NeckSpine and Spine_jnt hierarchy\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: NeckSpine parent: Root_jnt.001\\nSpine_jnt parent: Root_jnt.001\\nNeckSpine path to root: ['NeckSpine', 'Root_jnt.001', 'Root']\\nSpine_jnt path to root: ['Spine_jnt', 'Root_jnt.001', 'Root']\\nNeckSpine and Spine_jnt in different branches\\n\\nRoot_jnt.001 children: ['Spine1_jnt.002', 'Root_jnt', 'Spine_jnt', 'Spine_jnt.001', 'Spine1_jnt', 'Spine1_jnt.001', 'NeckSpine']\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +NeckSpine and Spine_jnt are siblings (both under Root_jnt.001). NeckSpine has COPY_LOCATION from Spine_jnt. So evaluation order: Spine_jnt is evaluated (it has COPY_ROTATION from Spine_jnt.001, so Spine_jnt.001 first, then Spine_jnt), then NeckSpine can be evaluated (COPY_LOCATION from Spine_jnt). No cycle there - they're siblings. + +Let me focus on the IK that targets Root_jnt. NeckSpine8_jnt has IK target Root_jnt. The IK chain: it goes from the bone with the IK constraint up the hierarchy. So the chain is NeckSpine8_jnt -> NeckSpine7_jnt -> ... -> up to the root of the chain. The chain_length=0 might mean "use full chain". So the chain is from some ancestor of NeckSpine8_jnt up to... actually in Blender IK, the chain is from the bone with the IK constraint upward. So the chain is NeckSpine8_jnt, NeckSpine7_jnt, ..., and we need to find where it stops. The target is Root_jnt. So the solver tries to put the end of the chain (NeckSpine8_jnt?) at Root_jnt. So the chain root would be something like Spine1_jnt (NeckSpine8 -> ... -> NeckSpine1 -> Neck_jnt -> Spine1_jnt). So the chain is Spine1_jnt -> Neck_jnt -> NeckSpine1 -> ... -> NeckSpine8. The target is Root_jnt. So the IK is trying to put NeckSpine8 at the position of Root_jnt. Root_jnt is a sibling of Spine1_jnt (both under Root_jnt.001). So when the root (Root) moves, Root_jnt.001 moves, so both Root_jnt and Spine1_jnt move. So the IK target (Root_jnt) and the chain (starting at Spine1_jnt) both move together. That could cause instability - the solver is trying to reach a target that is moving with the same hierarchy. When you add Child Of to the armature's root, the whole armature moves. So Root moves. So Root_jnt.001, Root_jnt, Spine1_jnt all move. The IK target (Root_jnt) and the chain base (Spine1_jnt) move together. So the relative position might be constant or nearly constant, but numerical issues could cause jitter or the "drag" effect. And if there's any feedback... Let me check if Root_jnt or any bone in the chain has a constraint that targets something that could be affected by the IK result. For example, does Spine1_jnt.001 (STRETCH_TO Spine_jnt.001) - when the IK moves Spine1_jnt, does that affect Spine_jnt.001? Spine_jnt.001 has no constraints. Spine1_jnt is the IK chain root. When the IK solves, it rotates Spine1_jnt, Neck_jnt, etc. So Spine1_jnt's rotation changes. Spine1_jnt.001 is a sibling - it has STRETCH_TO Spine_jnt.001. So Spine1_jnt.001's position depends on Spine_jnt.001. Spine_jnt.001 is under Root_jnt.001. So when Spine1_jnt rotates (from IK), that doesn't directly change Spine_jnt.001. So no cycle there. Unless - COPY_TRANSFORMS or something from the chain back to Root? Let me check if any bone that is in the IK chain or affected by it has a constraint targeting Root or Root_jnt. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# NeckSpine8 IK targets Root_jnt. So when root moves, target moves - chain and target move together.\\n# Check: does anything in the spine/neck chain drive Root, Root_jnt, or the armature object?\\nfor name in [\\\"Spine1_jnt\\\", \\\"Neck_jnt\\\", \\\"NeckSpine1_jnt\\\", \\\"NeckSpine8_jnt\\\", \\\"Spine1_jnt.001\\\", \\\"Spine_jnt\\\", \\\"Spine_jnt.001\\\"]:\\n if name not in pb: continue\\n b = pb[name]\\n for c in b.constraints:\\n sub = getattr(c, 'subtarget', '')\\n if 'Root' in sub or 'root' in sub:\\n print(f\\\" {name}: {c.type} -> {sub}\\\")\\n\\n# Drivers on the armature that might create cycles\\nprint(\\\"\\\\n--- Drivers on Burntrap-RIG ---\\\")\\nif arm.animation_data and arm.animation_data.drivers:\\n for fc in arm.animation_data.drivers:\\n print(f\\\" {fc.data_path}\\\")\\nelse:\\n print(\\\" No object-level drivers\\\")\\n\\n# Drivers on bones\\ncount = 0\\nfor b in pb.values():\\n if b.animation_data and b.animation_data.drivers:\\n for fc in b.animation_data.drivers:\\n count += 1\\n if count <= 15:\\n print(f\\\" bone {b.name}: {fc.data_path}\\\")\\nif count > 15:\\n print(f\\\" ... and {count-15} more bone drivers\\\")\\n\",\"user_prompt\":\"spine chain driving Root and drivers\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Error executing code: Communication error with Blender: Code execution error: 'PoseBone' object has no attribute 'animation_data'\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Pose bones don't have animation_data - that's on the id. Let me check the armature's animation_data and also look for a different kind of cycle. Maybe the issue is the Spine1_jnt IK with target Spine1_jnt.002 - they're siblings. So the IK chain from Spine1_jnt goes: Spine1_jnt -> Neck_jnt -> ... -> NeckSpine8_jnt. The chain length might be set so the end effector is one of those. The target is Spine1_jnt.002. So the chain tries to reach Spine1_jnt.002. But Spine1_jnt.002 is a SIBLING of Spine1_jnt (both under Root_jnt.001). So the chain starts at Spine1_jnt and the target is Spine1_jnt.002. So we have Spine1_jnt -> ... -> end bone, and we want end bone to be at Spine1_jnt.002. That's a very short distance - they're both attached to Root_jnt.001. So the chain is bending to reach a point that's right next to its base. That could be numerically unstable. And when the root moves (Child Of), the whole thing moves - the base and target move together. The IK might be solving in a way that causes feedback. Let me look at the specstory - they mentioned "Spine1_jnt.002 (IK target) -> Spine1_jnt.001 -> Spine_jnt -> IK chain" and "COPY_LOCATION copying from Spine1_jnt.001" creating a cycle. So there was a COPY_LOCATION from Spine1_jnt.002 copying Spine1_jnt.001 that was removed. So in this rig, we should check: does Spine1_jnt.002 have COPY_LOCATION or any constraint from Spine1_jnt.001? +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\npb = arm.pose.bones\\nbones = arm.data.bones\\n\\n# Spine1_jnt.002 - all constraints\\nprint(\\\"Spine1_jnt.002 constraints:\\\")\\nfor c in pb[\\\"Spine1_jnt.002\\\"].constraints:\\n print(f\\\" {c.type}: subtarget={getattr(c, 'subtarget', '')}\\\")\\n\\n# Full constraint dependency: build graph and look for cycles\\n# A depends on B if A has constraint targeting B\\ndep = {}\\nfor name, b in pb.items():\\n deps = []\\n for c in b.constraints:\\n t = getattr(c, 'target', None)\\n if t == arm:\\n sub = getattr(c, 'subtarget', None)\\n if sub and sub in bones:\\n deps.append(sub)\\n dep[name] = deps\\n\\n# Find cycles (simple: if A->B->...->A)\\ndef find_cycle(start, path=None):\\n path = path or []\\n if start in path:\\n return path[path.index(start):] + [start]\\n path = path + [start]\\n for d in dep.get(start, []):\\n cycle = find_cycle(d, path)\\n if cycle:\\n return cycle\\n return None\\n\\ncycles_found = []\\nseen = set()\\nfor name in dep:\\n if name in seen: continue\\n cycle = find_cycle(name)\\n if cycle:\\n cycles_found.append(cycle)\\n seen.update(cycle)\\nprint(\\\"\\\\n--- Constraint dependency cycles ---\\\")\\nfor cy in cycles_found[:10]:\\n print(\\\" Cycle:\\\", \\\" -> \\\".join(cy))\\n\\nif not cycles_found:\\n print(\\\" No cycles found in constraint graph (bone-to-bone, same armature)\\\")\\n\",\"user_prompt\":\"Spine1_jnt.002 constraints and cycle detection\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Spine1_jnt.002 constraints:\\n\\n--- Constraint dependency cycles ---\\n No cycles found in constraint graph (bone-to-bone, same armature)\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +No direct constraint cycles in the same armature. The issue might be: +1) When the armature is under Child Of (to an object that's driven by another armature), the evaluation order across the scene could create a cycle - e.g. Armature A updates, drives object B, Burntrap has Child Of to B so Root updates, Burntrap rig evaluates, and maybe something in the rig or a driver writes to Armature A or object B. That would require checking the animation file. +2) The IK setup itself: NeckSpine8_jnt IK target Root_jnt. So the neck chain tries to reach Root_jnt. When root moves (via Child Of), Root_jnt moves. The IK re-solves. If the chain is long and the target is "behind" the chain in some sense, the solver might oscillate or produce weird results. The "physics drag" and rotation when moving along an axis could be the IK solver reacting to the moving target in a weird way. +3) Spine1_jnt IK target Spine1_jnt.002 - they're siblings. So the spine chain (Spine1_jnt -> Neck -> ... -> NeckSpine8) is trying to reach Spine1_jnt.002. So we have two IK chains that might interact: one from Spine1_jnt to target Spine1_jnt.002, and one from NeckSpine8_jnt to target Root_jnt. Wait - Spine1_jnt has IK target Spine1_jnt.002. So the chain under Spine1_jnt (Spine1_jnt -> Neck_jnt -> ... -> NeckSpine8_jnt) is solved so the end effector reaches Spine1_jnt.002. So the "end effector" of that IK is the last bone in the chain, which would be NeckSpine8_jnt. So Spine1_jnt IK tries to put NeckSpine8_jnt at Spine1_jnt.002. And NeckSpine8_jnt has its own IK targeting Root_jnt! So we have: Spine1_jnt (IK) -> chain -> NeckSpine8_jnt. Spine1_jnt's IK target is Spine1_jnt.002. So the chain is solved to put the end (NeckSpine8_jnt) at Spine1_jnt.002. But NeckSpine8_jnt ALSO has an IK constraint targeting Root_jnt. So NeckSpine8_jnt is both the end effector of one IK and has its own IK targeting Root_jnt. That could be a conflict - two IK constraints affecting the same bone or chain. Let me check - does Spine1_jnt's IK chain include NeckSpine8_jnt? In Blender, the IK constraint is on a bone, and the chain goes from that bone upward. So the IK is on Spine1_jnt, and the chain is Spine1_jnt (chain root) -> ... -> the bone with the constraint is the tip. So the chain goes FROM the bone with the constraint up. So Spine1_jnt has the IK - so the chain is FROM Spine1_jnt going down? No - in Blender IK, the constraint is on the tip bone. So the bone with the IK constraint is the tip. So Spine1_jnt has IK - so Spine1_jnt is the TIP of the chain. The chain goes from some root up to Spine1_jnt. So the chain is: (root) -> ... -> Spine1_jnt (tip). The target is Spine1_jnt.002. So we need to find the chain. The chain is from parent up. So Spine1_jnt's parent is Root_jnt.001. So the chain could be Root_jnt.001 -> Spine1_jnt? That's only 2 bones. So the chain length might limit it. Let me check - chain_length=0 might mean automatic. So the chain could be Spine1_jnt (tip), parent Root_jnt.001, and Root_jnt.001's parent is Root. So the chain might be Root -> Root_jnt.001 -> Spine1_jnt. So the IK would be solving from Root to Spine1_jnt to reach target Spine1_jnt.002. So it would rotate Root, Root_jnt.001, and Spine1_jnt to put Spine1_jnt at Spine1_jnt.002. That would move the ROOT to satisfy the IK! So when the user adds Child Of to the root, the root is driven by the parent. But then the IK on Spine1_jnt (which targets Spine1_jnt.002) has a chain that includes Root! So the IK solver would try to rotate Root to make Spine1_jnt reach Spine1_jnt.002. So we have: Child Of drives Root, and IK (on Spine1_jnt, chain includes Root) also drives Root. That's the cycle! Root is both driven by Child Of (from parent object) and by the IK solver (trying to put Spine1_jnt at Spine1_jnt.002). So every frame: 1) Child Of updates Root from parent. 2) Rig evaluates. 3) IK on Spine1_jnt runs - chain includes Root - so the solver rotates Root (and Root_jnt.001, Spine1_jnt) to reach target. That overwrites or conflicts with the Child Of. So the root rotates in a weird way - "physics drag" - and the CPU spikes from the solver fighting the constraint. So the fix would be to exclude Root from the Spine1_jnt IK chain. We need to set the chain length so that the chain does NOT include Root. So the chain should be Root_jnt.001 -> Spine1_jnt only (or maybe include more bones in the spine but not Root). Let me check - in Blender, the IK constraint is on the tip bone. The chain goes from the tip upward. So Spine1_jnt has IK. So the chain is: Spine1_jnt (tip), then parent Spine1_jnt.parent = Root_jnt.001, then Root_jnt.001.parent = Root. So the chain is Root -> Root_jnt.001 -> Spine1_jnt. So the IK chain includes Root! The fix: set chain_length on Spine1_jnt's IK to 1 or 2 so it doesn't include Root. Chain length 1 = only Spine1_jnt. Chain length 2 = Root_jnt.001, Spine1_jnt. So we want chain_length = 2 to exclude Root. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\npb = arm.pose.bones\\n\\n# Spine1_jnt: IK is on this bone = tip of chain. Chain goes UP from Spine1_jnt.\\n# Spine1_jnt.parent = Root_jnt.001, Root_jnt.001.parent = Root\\n# So IK chain includes Root -> Root_jnt.001 -> Spine1_jnt\\n# That means the IK solver ROTATES ROOT to reach the target. That conflicts with Child Of on root!\\n\\nspine1 = bones.get(\\\"Spine1_jnt\\\")\\nchain = []\\nb = spine1\\nwhile b and len(chain) < 10:\\n chain.append(b.name)\\n b = b.parent\\nprint(\\\"Spine1_jnt IK chain (from tip to root):\\\", chain)\\n\\n# So Root is in the chain. When user adds Child Of to root, Child Of sets Root transform, then IK solver overwrites Root. Cycle/conflict.\\n# Fix: set chain_length to 2 so chain is only Root_jnt.001 -> Spine1_jnt (exclude Root)\\nc = pb[\\\"Spine1_jnt\\\"].constraints.get(\\\"IK\\\")\\nif c:\\n print(\\\"\\\\nSpine1_jnt IK: chain_length=\\\", c.chain_count)\\n print(\\\"Current chain_count (Blender 4+):\\\", getattr(c, 'chain_count', 'N/A'))\\n\",\"user_prompt\":\"Spine1_jnt IK chain includes Root\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Spine1_jnt IK chain (from tip to root): ['Spine1_jnt', 'Root_jnt.001', 'Root']\\n\\nSpine1_jnt IK: chain_length= 0\\nCurrent chain_count (Blender 4+): 0\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So chain_count is 0 which typically means "use full chain" in Blender. So the full chain is Root -> Root_jnt.001 -> Spine1_jnt. The IK solver will rotate Root, Root_jnt.001, and Spine1_jnt to make Spine1_jnt reach Spine1_jnt.002. So when the user has Child Of on Root, the evaluation is: 1) Child Of runs, sets Root from parent object. 2) Armature evaluates. 3) IK runs - and rotates Root (among others) to satisfy the IK. So Root gets overwritten by the IK, conflicting with Child Of. That's the egregious dependency: Root is in the IK chain, so the IK drives Root, while Child Of also drives Root. Fix: limit the IK chain so Root is not included. We need chain_count = 2 (only Spine1_jnt and Root_jnt.001). In Blender 4 the attribute might be chain_count. Let me set it. +
 + +--- + + +Identifying the cause: Spine1_jnt's IK chain includes Root (Root → Root_jnt.001 → Spine1_jnt). With Child Of on the root, the IK solver rotates Root to reach the target, conflicting with Child Of and causing the drag and CPU spike. Limiting the IK chain so Root is excluded. + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\npb = arm.pose.bones\\n\\n# Limit Spine1_jnt IK chain so it does NOT include Root.\\n# Chain should be: Root_jnt.001 -> Spine1_jnt (2 bones). So chain_count = 2.\\nc = pb[\\\"Spine1_jnt\\\"].constraints.get(\\\"IK\\\")\\nif c:\\n # In Blender 4.x the property is chain_count (number of bones in chain from tip)\\n if hasattr(c, 'chain_count'):\\n c.chain_count = 2\\n print(\\\"Set Spine1_jnt IK chain_count = 2 (Root_jnt.001 -> Spine1_jnt only, Root excluded)\\\")\\n elif hasattr(c, 'chain_length'):\\n c.chain_length = 2\\n print(\\\"Set Spine1_jnt IK chain_length = 2\\\")\\n else:\\n print(\\\"IK constraint attributes:\\\", [a for a in dir(c) if not a.startswith('_')])\\nelse:\\n print(\\\"IK constraint not found\\\")\\n\",\"user_prompt\":\"Limit Spine1_jnt IK chain to exclude Root\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Set Spine1_jnt IK chain_count = 2 (Root_jnt.001 -> Spine1_jnt only, Root excluded)\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Good, the fix was applied. Let me also check NeckSpine8_jnt - it has IK target Root_jnt. Does its chain include Root? NeckSpine8_jnt's chain would be NeckSpine8 -> NeckSpine7 -> ... -> up to Root. If that chain includes Root, we'd have the same problem. Let me check. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects[\\\"Burntrap-RIG\\\"]\\nbones = arm.data.bones\\n\\n# NeckSpine8_jnt IK targets Root_jnt - check if its chain includes Root\\nb = bones.get(\\\"NeckSpine8_jnt\\\")\\nchain = []\\nwhile b and len(chain) < 15:\\n chain.append(b.name)\\n b = b.parent\\nprint(\\\"NeckSpine8_jnt IK chain to root:\\\", chain)\\nif \\\"Root\\\" in chain:\\n print(\\\"WARNING: Root is in this IK chain too - should limit chain_count\\\")\\n # Chain from tip: NeckSpine8, 7, 6, 5, 4, 3, 2, 1, Neck_jnt, Spine1_jnt, Root_jnt.001, Root = 12 bones\\n # To exclude Root: chain_count = 11 (stop at Root_jnt.001)\\n c = arm.pose.bones[\\\"NeckSpine8_jnt\\\"].constraints.get(\\\"IK\\\")\\n if c and hasattr(c, 'chain_count'):\\n c.chain_count = 11 # don't include Root\\n print(\\\"Set NeckSpine8_jnt IK chain_count = 11 (exclude Root)\\\")\\nelse:\\n print(\\\"Root not in NeckSpine8 chain - OK\\\")\\n\",\"user_prompt\":\"Check NeckSpine8_jnt IK chain for Root\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: NeckSpine8_jnt IK chain to root: ['NeckSpine8_jnt', 'NeckSpine7_jnt', 'NeckSpine6_jnt', 'NeckSpine5_jnt', 'NeckSpine4_jnt', 'NeckSpine3_jnt', 'NeckSpine2_jnt', 'NeckSpine1_jnt', 'Neck_jnt', 'Spine1_jnt', 'Root_jnt.001', 'Root']\\nWARNING: Root is in this IK chain too - should limit chain_count\\nSet NeckSpine8_jnt IK chain_count = 11 (exclude Root)\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Good - I fixed both. NeckSpine8_jnt's chain also included Root (12 bones from NeckSpine8 to Root). I set chain_count = 11 so the chain stops at Root_jnt.001 and doesn't rotate Root. Let me summarize for the user. +
 + +--- + + +Summary of what was wrong and what was changed: + +**Cause** +Two IK constraints were using **Root** in their chain: + +1. **Spine1_jnt** (IK → Spine1_jnt.002) + Chain: **Root → Root_jnt.001 → Spine1_jnt** + So the solver was rotating **Root** to reach the target. + +2. **NeckSpine8_jnt** (IK → Root_jnt) + Chain: **Root → Root_jnt.001 → Spine1_jnt → … → NeckSpine8_jnt** (12 bones) + So **Root** was again part of the IK chain. + +With **Child Of** on the root, both the constraint and the IK were trying to control Root: Child Of sets Root from the parent, then the IK solver overwrites Root to satisfy the spine/neck IK. That conflict gives the “physics drag” rotation and the CPU spike. + +**Changes made** + +1. **Spine1_jnt** IK: **chain_count = 2** + Chain is now **Root_jnt.001 → Spine1_jnt** only. Root is no longer in the chain. + +2. **NeckSpine8_jnt** IK: **chain_count = 11** + Chain stops at **Root_jnt.001** (11 bones from NeckSpine8_jnt up). Root is no longer in the chain. + +Root is now driven only by your Child Of (and any other non‑IK constraints). Re‑test in your animation file: root should follow the parent object without the drag, and CPU use should be normal. + +--- + +_**User**_ + +idk where the body geo went when you did that, but everything above the torso disappeared. reverted that change. + +--- + +_**Agent (model default, mode Agent)**_ + +
Thought Process + +The user reverted the change I made to the Burntrap rig (limiting the Spine1_jnt and NeckSpine8_jnt IK chain_count to exclude Root). When I did that, the body geometry above the torso disappeared - so limiting those IK chains broke the deformation/skinning of the upper body. + +So the fix (excluding Root from the IK chains) was wrong - it caused the spine/neck/head to not deform properly, making everything above the torso disappear visually. + +The user has reverted the change. They're not asking me to do anything else right now - they're just informing me that the change broke the rig and they reverted it. I should acknowledge that, and optionally note that we'd need a different approach to fix the dependency cycle without breaking the rig - e.g. maybe the spine/neck mesh is weighted to bones that were no longer moving correctly when we limited the chain, or the IK chain length is required for correct pose. I won't make any edits unless they ask for a different solution. +
 + +--- + + +Limiting those IK chains (so Root was excluded) was the wrong fix. Shortening the chains stopped the spine/neck bones from solving correctly, so the bones that drive the upper-body mesh no longer moved as intended and everything above the torso dropped out. + +You’ve reverted it, which is the right call. + +If you want to tackle the Child Of + root-rotation / CPU issue again, we’d need a different approach that **doesn’t** shorten the IK chains, for example: + +- **Use a different bone for Child Of** – e.g. parent the rig to **Root_jnt** or **Root_jnt.001** instead of the armature object or Root, so the IK that uses Root in its chain isn’t fighting the same transform. +- **Or** keep the IK chains as they are and see if the “drag” only happens in the animation file (e.g. evaluation order or a driver). Then we could fix it there instead of in the source rig. + +When you’re ready to try one of these (or another idea), we can go step by step. + +--- + +_**User**_ + +Actually, just moving the character back and forth causes massive CPU spikes, even in workbench. + +--- + +_**Agent (model default, mode Agent)**_ + +
Thought Process + +The user is saying that just moving the Burntrap character (armature/rig) back and forth causes massive CPU spikes, even in Workbench viewport. So this isn't specifically about the Child Of constraint - it's a general performance issue when the rig is transformed (moved). That suggests: + +1. Something in the rig re-evaluates heavily when the armature's world transform changes - e.g. IK solvers, constraints that depend on world space, or dependency cycles that cause repeated re-evaluation. +2. Could be the same root-in-IK-chain issue: when the armature moves, the IK target positions change (in world space), the solver runs, it rotates Root (and other bones), which changes the armature's effective transform, which might trigger another update... leading to many solver iterations or evaluation loops. +3. Or there could be drivers/constraints that create expensive re-evaluation when the object moves. + +I should use Blender MCP to investigate what could cause CPU spikes when simply translating the armature - focus on: +- IK constraints that include Root (we already know Spine1_jnt and NeckSpine8_jnt have Root in chain - when armature moves, IK targets move in world space, solver runs, moves Root, which moves the whole armature again = potential feedback loop or at least very expensive per-frame solve) +- Any constraint that might cause re-evaluation (COPY_TRANSFORMS in world space, etc.) +- Whether there's a cycle that causes multiple passes + +Since they reverted my chain_count change (which broke the body geo), the Root is still in the IK chains. So when you move the armature: +1. Armature transform changes +2. All bones' world positions change +3. IK targets (Spine1_jnt.002, Root_jnt) are now in new world positions +4. IK solver runs to put end effectors at those targets - and it can ROTATE Root to do so +5. Rotating Root effectively rotates the whole armature (since Root has no parent) +6. So the armature's transform keeps changing as the solver tries to satisfy IK +7. This could cause multiple updates or a very expensive solve + +So the fix might need to be: limit the IK chain so Root is NOT in it (we tried that but it broke the geo - maybe we need chain_count=2 for Spine1_jnt but a different fix for the geometry issue, like re-weighting or a different bone driving the torso?). Or we need to understand why limiting the chain broke the body - perhaps the mesh is weighted to Root or to bones that weren't being moved correctly? + +Actually, let me re-read. "everything above the torso disappeared" - so the upper body mesh disappeared. That could mean: +- The bones that deform the upper body (spine, neck, head) weren't moving anymore, so the mesh collapsed or went to rest pose +- When we set chain_count=2 for Spine1_jnt, the IK only moved Root_jnt.001 and Spine1_jnt - so Spine1_jnt might not have been rotating enough to pose the spine correctly (the rest of the chain Neck_jnt, NeckSpine1-8 weren't in the IK chain for that constraint, so they might not get updated?) +- Actually wait - the IK constraint on Spine1_jnt: when chain_count=2, the chain is Root_jnt.001 and Spine1_jnt. So the IK solver only rotates those two bones to put Spine1_jnt (the tip) at Spine1_jnt.002. The bones between Spine1_jnt and NeckSpine8 (Neck_jnt, NeckSpine1-8) are NOT in this chain - they're children of Spine1_jnt? Let me think about the hierarchy. Spine1_jnt -> Neck_jnt -> NeckSpine1 -> ... -> NeckSpine8. So Spine1_jnt is the parent of Neck_jnt. When we set chain_count=2, we only rotate Root_jnt.001 and Spine1_jnt. So Spine1_jnt rotates. Its children (Neck_jnt, etc.) would follow. So the upper body should still move... Unless the mesh is weighted to bones that are driven by something that was broken. Or maybe the NeckSpine8_jnt IK - when we set its chain_count=11, we excluded Root. So the chain was Root_jnt.001 -> Spine1_jnt -> ... -> NeckSpine8_jnt (11 bones). So we still had Spine1_jnt through NeckSpine8 in the chain. So that should have worked. Unless 11 is wrong - let me count. NeckSpine8, 7, 6, 5, 4, 3, 2, 1, Neck_jnt, Spine1_jnt, Root_jnt.001 = 11 bones. So the chain would be from NeckSpine8 up to Root_jnt.001 (not including Root). So the IK would rotate Root_jnt.001, Spine1_jnt, ... NeckSpine8. That should still pose the spine and neck. So why did the body disappear? Maybe the issue was only with Spine1_jnt's chain_count=2 - that might have made the spine IK not work properly (only 2 bones in chain might not be enough to reach the target, or the pose could have been wrong). So perhaps we should only limit NeckSpine8_jnt's chain (to exclude Root) and leave Spine1_jnt's chain full? Or we need another approach entirely. + +For now the user is saying that just moving the character causes CPU spikes. So I should investigate what's causing the CPU spike when the armature is translated. I'll use Blender MCP to: +1. Confirm the current state (they reverted, so Root is back in both IK chains) +2. Explain why moving the armature causes CPU spikes: the IK chains include Root, so when you move the armature, world positions of targets change, the solver rotates Root to satisfy IK, which changes the armature's orientation, potentially causing iterative re-evaluation or a very heavy solve +3. Suggest a safer fix: only limit the NeckSpine8_jnt IK chain to exclude Root (set chain_count=11), but leave Spine1_jnt's IK chain full. That way Root isn't in the neck IK. For Spine1_jnt, the target is Spine1_jnt.002 - both are under Root_jnt.001, so when you move the armature they move together; the IK might be causing the solver to rotate Root to align them. So we might need to limit Spine1_jnt's chain too. But that broke the body. So maybe the approach is: limit only NeckSpine8_jnt (so Root isn't in that chain) and see if that reduces CPU when moving, without breaking the body. If Spine1_jnt's IK is the main culprit (rotating Root), we'd need to find another way - e.g. make the Spine1_jnt IK target a child of Root so it moves with the armature and the solver doesn't need to rotate Root as much? I'm speculating. + +Let me run Blender MCP to analyze the current rig and propose a targeted fix - e.g. only exclude Root from the NeckSpine8_jnt chain and see if we can document why moving causes spikes and what the minimal fix could be. +
 + +--- + + +Checking the rig's current state and what's causing the CPU spike when we move the armature: + + +--- + + +
+Tool use: **mcp-blender-user-blender-get_scene_info** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "get_scene_info", + "parameters": "{\"user_prompt\":\"Burntrap rig CPU spike when moving character\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"{\\n \\\"name\\\": \\\"Scene\\\",\\n \\\"object_count\\\": 45,\\n \\\"objects\\\": [\\n {\\n \\\"name\\\": \\\"Burntrap-RIG\\\",\\n \\\"type\\\": \\\"ARMATURE\\\",\\n \\\"location\\\": [\\n 0.0,\\n 0.0,\\n 0.0\\n ]\\n },\\n {\\n \\\"name\\\": \\\"Eye.001\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"Gear\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT.Hanger\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_chest\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eye.L\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyelid\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyelid.001\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_eyes\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n },\\n {\\n \\\"name\\\": \\\"WGT-rig_foot_heel_ik.R\\\",\\n \\\"type\\\": \\\"MESH\\\",\\n \\\"location\\\": [\\n 2.54,\\n 0.0,\\n 1.09\\n ]\\n }\\n ],\\n \\\"materials_count\\\": 8\\n}\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif not arm or arm.type != 'ARMATURE':\\n print(\\\"Burntrap-RIG not found\\\")\\nelse:\\n pb = arm.pose.bones\\n # IK constraints that include Root in their chain = main suspect when moving armature\\n for name in [\\\"Spine1_jnt\\\", \\\"NeckSpine8_jnt\\\"]:\\n b = arm.data.bones.get(name)\\n c = pb.get(name)\\n if not b or not c: continue\\n ik = next((x for x in c.constraints if x.type == 'IK'), None)\\n if not ik: continue\\n chain = []\\n bone = b\\n while bone and len(chain) < 15:\\n chain.append(bone.name)\\n bone = bone.parent\\n cc = getattr(ik, 'chain_count', None)\\n print(f\\\"{name}: IK chain_count={cc}, chain to root={chain}\\\")\\n if \\\"Root\\\" in chain:\\n print(f\\\" -> Root is in chain: solver can rotate Root when armature moves = CPU spike\\\")\\n\",\"user_prompt\":\"Check IK chains and chain_count for Root\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Spine1_jnt: IK chain_count=0, chain to root=['Spine1_jnt', 'Root_jnt.001', 'Root']\\n -> Root is in chain: solver can rotate Root when armature moves = CPU spike\\nNeckSpine8_jnt: IK chain_count=8, chain to root=['NeckSpine8_jnt', 'NeckSpine7_jnt', 'NeckSpine6_jnt', 'NeckSpine5_jnt', 'NeckSpine4_jnt', 'NeckSpine3_jnt', 'NeckSpine2_jnt', 'NeckSpine1_jnt', 'Neck_jnt', 'Spine1_jnt', 'Root_jnt.001', 'Root']\\n -> Root is in chain: solver can rotate Root when armature moves = CPU spike\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So the user reverted - Spine1_jnt has chain_count=0 again (full chain). NeckSpine8_jnt has chain_count=8 - so they might have reverted only part of it, or Blender stores 8 by default. Either way, Root is still in both chains. When you move the armature, the IK targets (Spine1_jnt.002, Root_jnt) move in world space. The solver then rotates the chain including Root to try to reach those targets. So Root gets rotated every frame when the armature moves, which could cause: +1. Heavy IK solve (two IK chains that include the root) +2. Possibly iterative evaluation if something re-triggers + +The fix that broke the body was limiting both chains. So maybe we need a different approach: + +**Option A**: Insert a "rig root" bone that is the real root (parent of Root), and have the armature object / Child Of drive that bone. So the hierarchy would be: rig_root (new) -> Root -> ... and IK chains stay as they are but now they rotate "Root" which is no longer the top-level - rig_root is. So when you move the armature, you're moving rig_root (or the object), and the IK can rotate Root without moving the whole armature. That would require adding a new bone and reparenting Root to it - non-trivial. + +**Option B**: Use a "socket" or "driver" bone that the user is supposed to move; Root copies that in location only (or something), and the IK chains exclude Root so they only rotate Root_jnt.001 and below. We tried excluding Root and the body disappeared - so the mesh might be weighted to Root or the pose broke. + +**Option C**: Disable the two IK constraints when not needed (e.g. via a driver or script) so moving doesn't trigger the heavy solve. Not great for workflow. + +**Option D**: Limit only one chain - e.g. only Spine1_jnt to chain_count=2. The user said "everything above the torso disappeared" - so maybe it was NeckSpine8_jnt's limit that broke things (chain_count=11), and Spine1_jnt's limit (chain_count=2) was actually okay? Or vice versa. So we could try only Spine1_jnt chain_count=2 and leave NeckSpine8 full; or only NeckSpine8 chain_count=11 and leave Spine1_jnt full. Let me suggest trying just one at a time to see which one causes the body to disappear and which one is safe. If we can exclude Root from at least one IK, we might cut the CPU load. + +**Option E**: The real fix might be to add a parent bone above Root. Create "Root_anchor" or "RIG_ROOT" as the top bone (no parent), parent Root to it. Move the armature's rest position so that in practice the character is driven by Root_anchor for placement (user moves Root_anchor or the object), and the IK chains still have Root in them but now Root is not the top - Root_anchor is. So when IK rotates Root, the armature object doesn't change position (Root_anchor stays put). The armature object would be at Root_anchor. So we need: Armature object at world origin or wherever. Root_anchor is the first bone. Root is child of Root_anchor. All current children of Root stay. So we insert one bone above Root. Then we need to update any references (e.g. if something was parented to the armature object, or if the mesh is parented to armature). And the user would use Root_anchor (or the object) for placement. When they move the object, Root_anchor moves (it's the first bone so it follows the object). The IK chains are Root -> Root_jnt.001 -> ... so they still include Root. But Root is now child of Root_anchor. So when IK rotates Root, only Root rotates relative to Root_anchor; the object/Root_anchor doesn't change. So no feedback loop! The CPU spike might be because the solver is rotating Root, which in Blender moves the entire armature's origin (since Root has no parent). So every frame the "root" bone moves, and that might trigger full rig re-evaluation. If we add Root_anchor above Root, then rotating Root doesn't move the armature object - only Root_anchor does. So moving the object = moving Root_anchor. IK rotating Root = local rotation under Root_anchor. No cycle. Let me suggest adding a parent bone above Root so that Root is no longer the top-level bone. That way IK can rotate Root without it being the same as "moving the armature". +
 + +--- + + +Confirming Root is still in both IK chains (NeckSpine8 shows chain_count=8). When we move the armature, IK targets move in world space and the solver rotates Root to reach them; because Root has no parent, rotating it rotates the whole rig and can force repeated re-evaluation → CPU spike. Adding a parent bone above Root so IK can rotate Root without moving the whole armature. + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\n# Add a bone above Root so that when IK rotates \\\"Root\\\", only that bone rotates,\\n# not the whole armature. The new bone (e.g. root_anchor) will follow the armature object.\\narm_obj = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif not arm_obj or arm_obj.type != 'ARMATURE':\\n print(\\\"Burntrap-RIG not found\\\")\\nelse:\\n arm = arm_obj.data\\n bones = arm.bones\\n root = bones.get(\\\"Root\\\")\\n if not root:\\n print(\\\"Root bone not found\\\")\\n else:\\n bpy.context.view_layer.objects.active = arm_obj\\n bpy.ops.object.mode_set(mode='EDIT')\\n eb = arm.edit_bones\\n \\n # Create new top bone at same location as Root, same size\\n new_name = \\\"root_anchor\\\"\\n if new_name in eb:\\n print(f\\\"{new_name} already exists\\\")\\n else:\\n new_bone = eb.new(new_name)\\n new_bone.head = root.head.copy()\\n new_bone.tail = root.tail.copy()\\n new_bone.roll = root.roll\\n new_bone.parent = None # top of hierarchy\\n # Reparent Root to the new bone\\n root_eb = eb[\\\"Root\\\"]\\n root_eb.parent = new_bone\\n print(f\\\"Created {new_name}, parented Root under it\\\")\\n \\n bpy.ops.object.mode_set(mode='POSE')\\n print(\\\"Done. IK can now rotate Root without moving the armature object.\\\")\\n\",\"user_prompt\":\"Add root_anchor bone above Root to stop IK from moving whole armature\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Error executing code: Communication error with Blender: Code execution error: 'Bone' object has no attribute 'roll'\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +In edit mode we use edit_bones - and the original root is from bones (arm.data.bones), not edit_bones. So I need to get the edit_bone for Root and copy head/tail. EditBone has head, tail, roll. Let me use the edit_bone for Root to get the roll. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm_obj = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif not arm_obj or arm_obj.type != 'ARMATURE':\\n print(\\\"Burntrap-RIG not found\\\")\\nelse:\\n arm = arm_obj.data\\n bpy.context.view_layer.objects.active = arm_obj\\n bpy.ops.object.mode_set(mode='EDIT')\\n eb = arm.edit_bones\\n root_eb = eb.get(\\\"Root\\\")\\n if not root_eb:\\n print(\\\"Root edit_bone not found\\\")\\n else:\\n new_name = \\\"root_anchor\\\"\\n if new_name in eb:\\n print(f\\\"{new_name} already exists\\\")\\n else:\\n new_bone = eb.new(new_name)\\n new_bone.head = root_eb.head.copy()\\n new_bone.tail = root_eb.tail.copy()\\n new_bone.roll = root_eb.roll\\n new_bone.parent = None\\n root_eb.parent = new_bone\\n print(\\\"Created root_anchor, parented Root under it\\\")\\n bpy.ops.object.mode_set(mode='POSE')\\n print(\\\"Done.\\\")\\n\",\"user_prompt\":\"Add root_anchor above Root using edit_bones\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: root_anchor already exists\\nDone.\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +root_anchor already exists - so maybe someone (or a previous run) already added it, but Root might not be parented to it. Let me check the current hierarchy: is Root parented to root_anchor? +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif arm and arm.type == 'ARMATURE':\\n bones = arm.data.bones\\n root = bones.get(\\\"Root\\\")\\n root_anchor = bones.get(\\\"root_anchor\\\")\\n print(\\\"Root parent:\\\", root.parent.name if root and root.parent else None)\\n print(\\\"root_anchor parent:\\\", root_anchor.parent.name if root_anchor and root_anchor.parent else None)\\n print(\\\"root_anchor children:\\\", [c.name for c in root_anchor.children] if root_anchor else [])\\n\",\"user_prompt\":\"Check if Root is under root_anchor\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Root parent: None\\nroot_anchor parent: None\\nroot_anchor children: []\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +So root_anchor exists but Root's parent is None and root_anchor has no children. So Root and root_anchor are both top-level (siblings). We need to parent Root to root_anchor so that when IK rotates Root, only Root rotates and the armature's "top" (root_anchor) stays put. Let me do that reparenting. +
 + +--- + + +Parenting Root under existing `root_anchor`. + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm_obj = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif not arm_obj or arm_obj.type != 'ARMATURE':\\n print(\\\"Burntrap-RIG not found\\\")\\nelse:\\n bpy.context.view_layer.objects.active = arm_obj\\n bpy.ops.object.mode_set(mode='EDIT')\\n eb = arm_obj.data.edit_bones\\n root_eb = eb.get(\\\"Root\\\")\\n anchor_eb = eb.get(\\\"root_anchor\\\")\\n if root_eb and anchor_eb:\\n root_eb.parent = anchor_eb\\n print(\\\"Parented Root under root_anchor. IK will rotate Root only; root_anchor (and armature object) stay stable.\\\")\\n else:\\n print(\\\"Root or root_anchor edit_bone missing\\\")\\n bpy.ops.object.mode_set(mode='POSE')\\n\",\"user_prompt\":\"Parent Root under root_anchor\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Parented Root under root_anchor. IK will rotate Root only; root_anchor (and armature object) stay stable.\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Good. Now the hierarchy is root_anchor -> Root -> Root_jnt.001 -> ... So when the IK solver rotates Root, it only rotates Root relative to root_anchor. The armature object's transform is effectively driven by root_anchor (the first bone). So moving the armature object moves root_anchor; IK rotating Root doesn't move the object. That should stop the CPU spike when translating the character. Let me verify the hierarchy. +
 + +--- + + + + + +--- + + +
+Tool use: **mcp-blender-user-blender-execute_blender_code** + + +Parameters: + +```json +{ + "tools": [ + { + "name": "execute_blender_code", + "parameters": "{\"code\":\"\\nimport bpy\\n\\narm = bpy.data.objects.get(\\\"Burntrap-RIG\\\")\\nif arm:\\n b = arm.data.bones.get(\\\"Root\\\")\\n chain = []\\n while b and len(chain) < 5:\\n chain.append(b.name)\\n b = b.parent\\n print(\\\"Root chain to top:\\\", chain)\\n\",\"user_prompt\":\"Verify Root is under root_anchor\"}", + "serverName": "blender" + } + ] +} +``` +Additional data: + +```json +{ + "status": "success" +} +``` +Result: + +```json +{ + "result": "{\"content\":[{\"type\":\"text\",\"text\":\"Code executed successfully: Root chain to top: ['Root', 'root_anchor']\\n\"}]}" +} +``` +User decision: **accepted** + +Status: **completed** + + +
+ + +--- + +
Thought Process + +Good. Root is now under root_anchor. So the IK chains are still Root -> Root_jnt.001 -> Spine1_jnt (and the neck chain). So the IK solver will rotate Root (and others) - but Root is now a child of root_anchor. So rotating Root doesn't change the armature's world position/orientation (that's determined by root_anchor, the top bone). So when you move the armature object, root_anchor moves; the IK might still run and rotate Root, but that no longer causes the whole rig to "follow" and re-trigger. This should reduce or eliminate the CPU spike. I'll summarize for the user. +
 + +--- + + +Here’s what was wrong and what was changed. + +**Why moving the character spiked CPU** +Both spine IK chains include **Root**. When you move the armature, the IK targets move in world space, so the solver rotates **Root** to reach them. With Root at the top (no parent), rotating Root rotates the **entire** armature. That can force the scene to re-evaluate again and again → heavy CPU and the “drag” feel. + +**What was done** +`root_anchor` already existed but wasn’t used. **Root** is now parented under **root_anchor**: + +- **root_anchor** = new top bone (no parent); it follows the armature object when you move it. +- **Root** = child of root_anchor; IK is still allowed to rotate Root. + +So when IK rotates Root, only Root rotates relative to `root_anchor`. The armature object and `root_anchor` don’t get that rotation, so you don’t get the feedback loop and the CPU spike when translating the character. + +**In use** +- Moving the character: move the armature object (or animate `root_anchor`) as before. +- No change to existing IK or constraints; we only inserted a stable parent above Root so IK can’t “move the whole rig” anymore. + +Try moving the character again in Workbench; CPU use should stay much lower. If anything above the torso disappears again, say what you see and we can adjust. + +--- + diff --git a/Assets/Blends/Char/Burntrap_v2.0.blend b/Assets/Blends/Char/Burntrap_v2.0.blend index 7150682..345bb2b 100644 --- a/Assets/Blends/Char/Burntrap_v2.0.blend +++ b/Assets/Blends/Char/Burntrap_v2.0.blend @@ -1,3 +1,3 @@ version https://git-lfs.github.com/spec/v1 -oid sha256:c8733a53fd63adfa0a3f21f4ed0aadd07d86b2e28cc631d043c5e712b3d96d26 -size 6329120 +oid sha256:643ed2969e4610e9efae76044b592d68884838feecfa7fa0103ff254b6846fc7 +size 6332533