af0cfcb01c
Switch from Standard Surface to OpenPBR as the exported MaterialX surface, since this is the new standard more renderers are adopting and it more closely matches the Principled BSDF implementation. Anisotropy support is improved though still not quite the same, as formulas are different. Nodes are generated to apply anisotropic rotation to the tangent vector, as there is no corresponding parameter in OpenPBR. Fixes #138164 Authored by Apple: Lee Kerley Pull Request: https://projects.blender.org/blender/blender/pulls/138165