Animation-only FBX files (no mesh, clips only) could not be used:
clips are keyed by node index into the parsed model's node table, so
there was no path to get them onto a different model's skeleton.
Add AssetManager::AttachAnimationClips: parses the container with the
CPU-only path (no GPU upload -- empty meshes cannot build a Model),
remaps each clip's channels to the target model's node indices by
bone name, and appends to its clip list. Channels whose bone name is
absent are skipped and counted; clips with zero matching channels are
dropped. Same-source attach is idempotent via a new
AnimationClip::sourcePath marker; name clashes get the file stem
prefixed.
Inspector Animation block gains an attach slot (UE Details semantics)
listing model-container files plus a bullet list of attached sources;
already-attached paths are replayed idempotently when the entity is
selected, so clips survive restarts. The paths persist in the scene
(Animation.Attached); the clips themselves stay runtime state.
Limitations (documented, by design): same-skeleton retargeting only
-- bone names must match between source and target (same DCC export
or Mixamo-style per-animation downloads); cross-skeleton retargeting
is out of scope.
atdunbg
90bf63e641