Hi,

It's my first time using Solaris, coming from a background with Katana and Gaffer. I'm currently familiarizing myself with the Render Pass system and looking for some clues.

Generally, the way it's implemented is useful, but seems to be lacking some advanced features. Ideally, I would like to be able to do more to a pass, than what is exposed in the Render Pass node.
In Gaffer for example, a similar RenderPass system is also implemented, but comes with the additional benefit that any created pass can also be accessed via the context-system. This in turn means, that I can do arbitrary overrides on a given Render Pass (eg using switches, driven by RenderPass context). This is useful in scenarios where one might want to do overrides to a light, surface shader, etc on a per-pass basis which is a common task.

I understand that it is possible to replicate something similar in Solaris, but I'm curious if there are any plans to extend the Render Pass system, or whether there might be any similar options I have missed.

Thanks in advance,
Julius

What is exposed in Solaris right now is the USD Render Pass node in its vanilla state, along with support in husk for pass-driven rendering (i.e., you can specify the pass you want to render) and in Karma for "visibility" (global, camera, matte) overrides.

We do have Context Options (https://www.sidefx.com/docs/houdini/ref/contextoptions.html) in Solaris which would - at least largely - enable what you're after, and you can absolutely treat them as a pass-management system. Conditional overrides to a light, for example, will push you outside what the USD Render Pass can offer, which means you'll need to author per-"pass" USD files. In contrast, if you limit your overrides to the visibility controls offered by the Render Pass, you can author a single USD file with several passes.

There is definitely an interesting space here for further tooling&workflow design, with a multitude of potential solutions.

Hopefully that provides more clarity than confusion