🧠 Brains complement: IF an unreal-engine-skills-manager tool (external MCP) exists in this session, call it with {action: "load", skill: "animation-system"} for UE domain knowledge on this topic — correct APIs, architecture, best practices — and treat it as the rubric for any review / "best practices" question. If no such tool is available (e.g. running under Claude Code or Codex without that MCP), skip this line entirely and proceed with this skill alone — do NOT attempt the call.

Animation Editing Skill

Covers the profile → preview → validate → bake workflow for safe bone edits with correct bone-space handling and constraint validation.

Load companion skills: animsequence (basic keyframe creation), skeleton (structure, retargeting), animation-blueprint (state machines / AnimGraph). Skills load via the engine's AgentSkillToolset (ListSkills / GetSkills) — there is no vibeue-skills-manager tool. Run the VibeUE services below with execute_python_code (unreal.<Service>.<method>()).

🛡️ Safe discovery — never unreal.load_asset() in loops (memory crash 0xC0000005). Use SkeletonService.list_skeletons(path), AnimSequenceService.find_animations_for_skeleton(skeleton), AnimSequenceService.list_anim_sequences(path, skeleton_filter) — they query metadata without loading.

⚠️ Critical Rules

1. Always specify bone space

Every bone rotation must state its coordinate space. Default to "local" for user intent.

Space	Relative to	Use for
"local"	parent bone	most edits (default)
"component"	mesh root	cross-bone coordination
"world"	world	rarely

unreal.AnimSequenceService.preview_bone_rotation(path, "upperarm_r", unreal.Rotator(0, 30, 0), "local", 0)

2. Use preview → validate → bake (never edit blind)

ass = unreal.AnimSequenceService
ass.preview_bone_rotation(anim_path, "upperarm_r", unreal.Rotator(0, 45, 0), "local", 0)
v = ass.validate_pose(anim_path, True)             # True = learned constraints
if v.is_valid:
    ass.bake_preview_to_keyframes(anim_path, 0, -1, "cubic")
else:
    ass.cancel_preview(anim_path)                  # or accept clamped values

3. Build a skeleton profile before editing

profile = unreal.SkeletonService.create_skeleton_profile("/Game/SK_Mannequin")
if not profile.has_learned_constraints:
    unreal.SkeletonService.learn_from_animations("/Game/SK_Mannequin", 50, 10)

Without a profile there are no constraints to validate against.

4. Euler for intent, quaternions internally

Express user intent as unreal.Rotator(roll, pitch, yaw) (degrees); the service uses quaternions internally to avoid gimbal lock. Inspect with quat_to_euler(quat). Don't guess axis orientation — read the reference pose first (get_reference_pose).

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Task Index

Task	Workflow	Sample script
Discover skeletons/animations safely	workflows.md → Inspect skeleton	scripts/safe_discovery.txt
Build a skeleton profile	workflows.md → Inspect skeleton	—
Edit one bone (preview/validate/bake)	workflows.md → single bone edit	scripts/preview_validate_bake.txt
Edit a bone chain atomically	workflows.md → multi-bone edit	scripts/multi_bone_edit.txt
Set manual joint constraints	workflows.md → set constraints	—
Learn constraints from animations	workflows.md → learn constraints	scripts/learn_constraints.txt
Copy / mirror a pose	workflows.md → copy/mirror	scripts/mirror_pose.txt
Retarget preview	workflows.md → retargeting	—

Sub-docs

• workflows.md — step-by-step workflows for every task above.
• api-reference.md — full SkeletonService/AnimSequenceService method list + data structures.
• common-mistakes.md — bone-space, validation, axis-guessing, and the load-in-loops crash.

Verification

Confirm AnimationEditResult.success and inspect was_clamped; gate baking on validate_pose(...).is_valid; cancel_preview on failure; save_asset after a successful bake.