Volumetric Grid Displacement not working in Maya

[trainofthought]

Hi there,

This issue seems common to Vray 4.3 CPU and CUDA - displacement won't work for me on a volume grid, no matter what noise map or method I use. I'm trying to get more detail out of my cloud volume as illustrated in the documentation here: https://docs.chaosgroup.com/display/VMAYA/Displacement Just can't make it happen. Please help!

Scene file attached. Many Thanks

[hermit.crab]

The VRayVolumeGrid displacement works only with 3d maps. You could use a projection node between the texture and displacement, however, that won't work on GPU for the moment. Your best bet is to use the Volume Noise.
Another thing, your scene seems to be extremely huge, so you need to pump-up the numbers to get a visible result.

[trainofthought]

Thanks for your reply Alex, it's appreciated.

It really does seem that I just keep constantly running into limitations of GPU rendering, no matter what I do. This is the 3rd major issue while trying to do a single shot of my film. I was hoping that this many years into development Vray GPU would be as fully featured as CPU by now. I may have to buy a threadripper or switch to Redshift at this rate :/

[trainofthought]

Hi again,

Coming back to to project - I've tried Volume Grid displacement with volume noise, which seems to work when mapped onto objects but has no effect on volume displacement. I've made the scene scale more manageable and it works fine with the CPU renderer, but is still not working on GPU in Vray 5 - can I please request this feature be looked at? Thanks!

[hermit.crab]

Yes, support for displacement of Phoenix Volumetrics in V-Ray GPU is not yet supported. It is on our developers' to-do lists though (internal bug-tracker id: PHI-3533).