Warren Moore

Thanks to the `KHR_materials_anisotropy` extension and cgltf v1.14, we have first-class support for anisotropy in the `GLTFAsset` API, but this isn't yet wired up in RealityKit material import. The task...

The [README](https://github.com/KhronosGroup/glTF-Sample-Assets/blob/main/Models/NormalTangentMirrorTest/README.md) for the NormalTangentMirrorTest sample asset contains the following text: "Note that this model (`NormalTangentTest`) does not supply tangent vectors, and specifically tests a rendering engine's ability to generate...