This question is about USD animations playing correctly in macOS Preview but not with RealityKit on visionOS.
I have a USD file created with 3D Studio Max that contains mesh-based smoke animation:
https://drive.google.com/file/d/1L7Jophgvw0u0USSv-_0fPGuCuJtapmzo/view (5.6 MB)
Apple's macOS 14.5 Preview app is able to play the animation correctly:
However, when a visionOS app uses RealityKit to load that same USD file in visionOS 2.0 beta 4, built with 16.0 beta 3 (16A5202i), and Entity/playAnimation is called, the animation does not play as expected:
This same app is able to successfully play animation of a hierarchy of solid objects read from a different USD file.
When I inspect the RealityKit entities loaded from the USD file, the ground plane entity is a ModelEntity, as expected, but the smoke entity type is Entity, with no associated geometry.
Why is it that macOS Preview can play the animation in the file, but RealityKit cannot?
Thank you for considering this question.
Preview uses Storm, not RealityKit. They have different capabilities as listed here: https://developer.apple.com/documentation/realitykit/creating-usd-files-for-apple-devices
