VRayVolumeGrid as matte object/holdout?

[Dan Andersen]

It's often desirable to render out dynamic volumes coming from FX (smoke, clouds, etc) in a separate layer from static, "ambient" volumes (atmosphere, fog etc). For these layers to merge properly in comp, it requires the FX volumes to be rendered as hold-outs in the static volumes layer. I have yet to find a way to achieve this, making us rely on hacks to merge the elements in Nuke.

I am aware the whole issue is avoidable with deep exr - which we do use in some cases - but going that route carries its own set of issues/limitations which means it's not an ideal default solution for us.

Is there any way to make one VRayVolumeGrid "punch a hole" in the alpha of another VRayVolumeGrid?

Thanks,
Dan

[georgi.zhekov]

Hey,

I'm afraid this is still in the to do list. Adding one more vote for it.

[Dan Andersen]

Ok, thanks for letting me know. I do hope it makes its way to the top of the list in the foreseeable future, since it's a recurring challenge here (and the comp-hack solutions are never quite right).

[georgi.zhekov]

Will update the thread as soon as we have something. Thanks!