By just changing the attribute name in the usd file from normal3f normals to vector3f primvars:normals I was able to get a proper render with Arnold. Now interestingly, after doing that, I still get artifacts with arnold.Īfter further testing, I found that this is because Arnold uses primvars for the normals like this : vector3f primvars:normals while maya exports them as just a usd normal attribute like this normal3f normals.

There is actually a way to get maya to export the normals, it's by giving a boolean custom attribute USD_EmitNormals to the shape nodes and set them to true for the ones we desire to have their normals emitted (exported). Same object can be exported from another DCC (ex from houdinj) and the issue happens again with arnold render.Īfter further digging and testing exports from different tools, this is what I found : Same usd file can be re-imported back to maya as a native object and it will render fine.

The assets we work on come primarly from tesselated surface nurbs in other apps like Vred, so this issue prevents us from using usd with arnold in production. Maya 2020 (tested on Maya 2022.3 aswell).The object in usd should render the same way as with native maya or alembic objects. Hide the native maya object and render the usd one, save a second snapshot.Render the native maya object alone, save a snapshot.The difference can be seen in the screenshot bellow, the same object rendered in usd (staged with maya-usd or simply as a standin) vs as a maya native object. Reflections look broken on tessellated surfaces that are read from a usd file

Arnold render settings maya 2020