Does Storm support OSD CPU tessellation?

Community Hydra
1

Hi everyone,

As I know, current OpenSubdiv refinement seems to do tessellation computation in GPU through specific tessellation related stages. For a few backend (e.g. WebGPU) there is not tessellation supported, is that possible to use OSD CPU tessellation? But it seems I cannot find where to enable it. Or it is not supported yet in Hydra Storm.

Thanks,
Francis

2

Hi Francis,

OSD supports CPU tessellation, and it looks like our Hydra Storm subdivision computation class does support CPU refinement: https://github.com/PixarAnimationStudios/OpenUSD/blob/release/pxr/imaging/hdSt/subdivision.h … However, hdSt/mesh.cpp is currently only calling GPU versions of the computation.

For uniform refinement I thought we only use compute shaders, not tessellation shaders? We have an adaptive refinement mode that definitely does rely on tessellation shaders, and would likely need to be disabled, but that’s currently an opt-in at the asset level anyway.

Hope this helps!
Tom