The variation in the surface normal vectors in a material, relative to surface tangent coordinate space.
Mac Catalyst 13.0+Beta
Model I/O uses this semantic for the objectTangentSpaceNormal and map_objectTangentSpaceNormal attributes when importing from the MTL file format (for assets in the OBJ file format).
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.