Integration of Pixar's Universal Scene Description into Unity. UPDATE: This package has been superseded by our new bundle of USD packages. Please see README & link below for further details.
There appears to be a bug in ImportMesh.UnrollFaceVarying, this may or may not be related to indexed UVs.
A test case from an external user looks wrong when imported, however breaking the mesh into polygon soup with no shared vertices results in the correct UV mapping, so some part of the unrolling process is failing.
For context: FaceVarying UVs in USD indicates that for every face, there exists one UV per vertex in the face. For example, a mesh with two triangles with two shared vertices (e.g. vertexCount == 4, indexCount = 6), will result in 6 UVs, not 4. The motivation for doing this is UV seams, where there is a break in the UV topology, but not in the mesh topology (which is desirable because unwelding the mesh topology would affect tessellation of the mesh during subdivision). Finally, because indexing UVs is typically still a win, a separate index array is optionally provided for UVs.
jcowles
commented
5 years ago
There appears to be a bug in ImportMesh.UnrollFaceVarying, this may or may not be related to indexed UVs.
A test case from an external user looks wrong when imported, however breaking the mesh into polygon soup with no shared vertices results in the correct UV mapping, so some part of the unrolling process is failing.
For context: FaceVarying UVs in USD indicates that for every face, there exists one UV per vertex in the face. For example, a mesh with two triangles with two shared vertices (e.g. vertexCount == 4, indexCount = 6), will result in 6 UVs, not 4. The motivation for doing this is UV seams, where there is a break in the UV topology, but not in the mesh topology (which is desirable because unwelding the mesh topology would affect tessellation of the mesh during subdivision). Finally, because indexing UVs is typically still a win, a separate index array is optionally provided for UVs.