RLMeshRotationTransformFn
All callables receive borrowed inputs and transfer their owned output Value, even on failure. State transfers only on successful construction. Transforms may be called concurrently; their clones share identity and user_data.
typedef RLMeshStatus (
*RLMeshRotationTransformFn
)(void* user_data, const RLMeshValue* value, RLMeshValue** out)