Animation setup

Get clip and joint names from inspect-glb; never guess them.

• For one clip, use the surface's simple playback path. For blending, transitions, or events, adapt an AnimStateGraph from an official animation example with find-examples.
• Put the anim component on or above the rendered skinned hierarchy, not on a separate pivot.
• Clamp every 1D blend parameter to its first and last child points. The Engine does not; values outside the span zero every weight and can make synced speeds non-finite, freezing the pose.
• Retarget only when each source animationTargets path, minus its .translation, .rotation, .scale, or .weights suffix, matches a destination nodePaths entry below the model root. Equal joint counts or similar names are not enough.
• Scale a wrapper, never skinned bones.

Prove playback

An active state or advancing state time does not prove motion. Sample two non-root joints over several rendered frames (inspect-runtime) at idle and at both ends of each blend tree. Zero joint motion means a binding, playback, or blend-weight failure.