Hi folks,
So I’ve been trying to figure out if I can do something very specific using volumes and LPE (using vray volume grid loading normal VDB files) and and I can’t figure out the most elegant way to go about it, for instance, if I have 2 or more normal geometry mesh objects, and in an LPE I use the object tag to wildcard one object in, it will automatically “matte” the other object(s) (yea I know it doesn’t change alpha, this is non issue) This also works if I have a volume grid and i use the " CV.* " LPE, the geo goes black, things are held out (again, I’m aware of alpha). What I’m trying to do now is basically use the CV.* flag with the LPE properties for the volumes, so in this case " CV.‘volA’.* "(I know syntax is probably wrong here but this is just example) so I can just spit out the volume I want, with proper “matting” of the other volume, so in the end, I have a normal beauty render with both volumes, but in the split out LPE, I get volA as one LPE, and volB as the other.. The only way I can do this at the moment is pretty cludgey by:
1. matting the universe and
2. making the volA grid I want its normal volumetric color, and volB a black constant
3. reverse the colors and do it again. This means minimum of 2 renders
if the LPE’s supported the object tags like geometry (you can in fact tag them in vray properties, but they do nothing) it would be a perfect solution.
TLDR;
I’d like to be able to stream each vol to its own LPE/render element (whichever way would work better) in one render, kinda like how extratex works, with the volumes occluded by the other volumes/objects
beauty
LPE-volA
LPE-volB
I know it sounds like a weird request, but its mostly because I can’t comp with deeps for this because large.
cheers if anyone has a way to do this 
Yeah I’d be curious to see if there was a way to split the grids out other than the obvious hacky style (maybe its because all volumes fall under the single vray volume grid env entry or something) but yeah I’d love to know for sure