Function removeFromScene

Remove an entity from the scene, undoing what addToScene did. Accepts the same union as addToScene: a Mesh, light, camera, shadow generator, transform node, or a whole AssetContainer. Safe to call more than once (idempotent).

Mesh GPU lifetime contract. Removing a mesh from its LAST scene disposes it: it releases its claim on every GPU resource it owns (geometry, skeleton, morph targets, thin instances). Those resources are shared and ref-counted, so each one survives while another owner remains — another scene holding the same mesh, a cloneTransformNode clone, or another glTF node sharing the primitive — and is destroyed once the last claim goes away. Either way the mesh itself is retired permanently and addToScene throws if it is added back: its buffers may be gone, and releasing a second claim it no longer holds would free buffers a surviving sibling still renders with. Removing a mesh from one of SEVERAL scenes holding it is not a disposal, so re-adding it there is fine. Otherwise create a new mesh — and to hide a mesh temporarily, set mesh.visible = false (or setSubtreeVisible) instead of removing it.

Standalone function for tree-shaking — only included when actually used.