Arnold 7 cannot read usd primvars for instanced geo in htoa/mtoa

[dlekanis]

Is there anyone that has the same issue?

Describe the bug

I am testing a layout setup inside Solaris, where I generate per instance geo primvars to control shading variations.

While everything works fine inside Houdini Hydra with Arnold, and the shading variations work fine, when rendering the cached usd file with a standin, either in htoa or mtoa, the primvars are not being picked up and the shading variation doesn't work.

Replicate the bug

• bring multiple copies of the same packed primitive, with different integer index attibutes, inside Solaris and apply a shader with where we color jitter the diffuse Color using the index attribute inside a user_data_int
• Test if it works inside Solaris
• Save the Usd, and try to render it from a procedural, checking if the shading variations get picked up
• In the packed primitive option of Sop import/sop create, change to xforms or unpack, save as a different version and test if the error exists for this one too

Expected Behaviour

Expected the result from the Arnold procedural to give me the same shading variation as when rendered inside Solaris.

Screenshots

Render inside SolarisRender from Arnold Procedural

Used Software Versions

• Arnold 7.0.0.3
• Htoa 6.0.2.2
• Houdini 19.0.531
• OS: centos 7
• USD Version: 21.08

File:

testUsdPrimvars.zip

[Stephen.Blair]

@ Can you post your test scene please?

[dlekanis]

Added it in the main description

[Stephen.Blair]

The second usd file doesn't work at all with the procedural. I get

00:00:03   190MB ERROR   |      [usd] Failed to open file ()
00:00:03   190MB WARNING |      [ginstance] /torus2/torus_0002: trying to clone a NULL object
00:00:03   191MB WARNING |      [ginstance] /torus2/torus_0001: trying to clone a NULL object
00:00:03   191MB WARNING |      [ginstance] /torus2/torus_0000: trying to clone a NULL object

And if I write out the usd files again, neither of them works ("Failed to open file" )