A description of how a submesh's index buffer data is arranged and how that arrangement should be used to produce the submesh's intended 3D shape.
- iOS 9.0+
- macOS 10.11+
- tvOS 9.0+
- Model I/O
Model I/O creates topology objects when importing assets containing non-uniform index buffers (that is, index buffers not composed of a single primitive type such as triangles or quads). You can also use topology objects (or load assets from file formats supporting topology information) to describe models for surface subdivision, identifying which edges or vertices remain sharp or become smooth when you use the