Arnold ROP: Cryptomatte AOVs

Is there an existing issue for this?

[X] I have searched the existing issues.

Please describe the feature you have in mind and explain what the current shortcomings are?

Arnold is known for rendering the Cryptomatte separately, even when merged AOVs are configured - so extra testing is needed to confirm Arnold ROP works with Cryptomattes currently with how layers are merged or not.

With the https://github.com/ynput/ayon-houdini/pull/72 it's unclear whether there are issues with the Cryptomatte AOV and whether everything functions as intended when rendering to a single file or not.

So, this would be follow-up on https://github.com/ynput/ayon-houdini/pull/72 and in particular to resolve the points mentioned in this comment.

How would you imagine the implementation of the feature?

[x] Confirm merged AOVs (no separate files configured) works as intended when rendering output files with Cryptomattes. There should be no errors and if the cryptomatte ends up being separate (because Arnold forcing that) the publishing should pick up the files to become an extra product.
[x] And fix any issues if there are any

Are there any labels you wish to add?

[X] I have added the relevant labels to the enhancement request.

Describe alternatives you've considered:

No response

Additional context:

So the core of this issue is to first test the functionality more - and confirm the different edge cases of how the Cryptoatte AOVs get rendered from Arnold.

ynput / ayon-houdini