Bifrost graphs are not property exported to Arnold USD files

[jonahfriedman]

Describe the bug Bifrost graphs can live in .ass files just fine, but inside an Arnold-USD they do not execute. This is probably due to the input0 serialized data which is not converted in the same way in the two plugins.

To Reproduce Steps to reproduce the behavior:

1. In Maya, create a Bifrost graph which creates a sphere using create_mesh_sphere.
2. Export a .ass file with expand procedurals OFF
3. Export an Arnold USDA file with expand procedurals OFF
4. Kick the .ass file file (see: https://docs.arnoldrenderer.com/display/A5AFMUG/Bifrost+Graph). It will render correctly.
5. Kick the .usd file. It will not render correctly and give an error message.

00:00:05   579MB ERROR   |  [bifrost] /bifrostGraph1/bifrostGraphShape1: input input0 is missing the bifrost:input0 declared parameter
00:00:05   580MB ERROR   |  [proc] /bifrostGraph1/bifrostGraphShape1: error in user init from

Inside the files, you can see the input0 serialized data is rendered differently in .ass and usda forms.

See also: BIFROST-7914

Used Software Versions

• Arnold: 7.1.3
• MayaUSD 0.18
• OS: Windows 10

sphere_ass_and_usd.zip

[autodesk-oss-arnold-bot[bot]]

Issue synced internally to ARNOLD-13316