Issues rendering primvar based cryptomattes

Hi,

Has anyone been able to render a primvar based cryptomatte in Solaris? It seems to output a default .5 .5 .5 value no matter what I feed it. Does it expect a certain data type or naming convention?

On Houdini 19.5.435 Vray 6.10.09

Thanks,
Chris

Hello @chris_elmer ,

We’re doing nothing particularly different, or requiring a special setup with Solaris - I’ve attached one of our test scenes we use to ensure parity with Karma’s output in terms of generated object hierarchy. Could you please give it a go to see if it clarifies the workflow?

As to steps to take in general:
1. Add a primvar on your geometry
2. Add a RenderVar LOP - set it to type “Primvar”, put your primvar in the field above, and enable Cryptomatte on the V-Ray tab.
3. Proceed with Render Product + Render Settings LOPs

Best regards!
HOU-3648.forForum.hip.zip (499 KB)

It looks like it needs a primvar that has constant interpolation. My issue was trying to drive the crypto with a per vertex primvar. I confirmed this in your file. If I swap in a per vertex primvar, it doesn’t work. Easy enough to change the primvar type on my end. Thanks!