The angle at which anisotropic effects are rotated relative to the local tangent basis.
- iOS 9.0+
- macOS 10.11+
- tvOS 9.0+
- Model I/O
Values for this semantic in the range from
1 map to angles from
2 * M. This semantic has no effect in a mesh that does not contain vertex attribute data providing a tangent basis.
Model I/O uses this semantic for the
map attributes when importing from the MTL file format (for assets in the OBJ file format).