How to Exclude a render pass from combined pass

I want to exclude my volume from the combined pass. If I select Volume Direct in the layer properties I get a separate volume layer, which works great. But I don’t want this volume in the combined pass anymore.
Is there any way I can remove it from the combined pass?

I know I could do it if I rendered all the passes separately and then combined them. But I only want a select few passes and don’t want to create a massive node tree in the compositor.

I also know I could use render layers, but that will slow renders because I need to load the scene twice.

Any help would be great :slight_smile:

Substracting would work for passes that combine your final image as structured in Blender Cycles documentation. I believe that volume isn’t just a plus operation after everything. Did a fast test and didn’t worked. Quite sure that you will have to render again without volumes.

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But you can render it as a separate pass, so wouldn’t that mean you could also subtract it from the combined pass?

In theory yes, but from documentation, Cycles isn’t considering volume as part of combined pass. Probably is a different math operation to combine volume. You might find a better solution in Cycles Dev forum.

Thanks for your help,
My current solution is just rendering out all the passes then combining them in compositing, this way I can have a seperate volume pass.


It is also odd how this filter doesn’t filter out volumes.

I thought that you already have the combined pass and didn’t want to render again. But this might work. Glad to help.

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yea, the volume filter is slightly unrelated but maybe it only filters smoke?
Anyways :slight_smile:

It works for me in 3.0.0 alpha. It filters out Volume objects, not meshes with a volume shader, which might be where the confusion is coming from.

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Yea, that’ll be it. I was using a volume bsdf in the shader editor

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