looking for help getting .vdb particles from houdini to render

[Harrison W]

Hello!

I am having trouble rendering some particle vdb's exported from houdini. There seems to be a lack of info on the vray volume grid and I have yet to find any helpful solution out there and establish a decent workflow.

1) In houdini I have the particle simulation cached as points and then using the 'convertvdbpoints' node before caching it out as .vdb format.
2) In maya I create a vray volume grid from the shelf, then I browse to my vdb cache and select the houdini preset upon the prompt. All appears normal and I can see my particles in the viewport just as they look in houdini. I also transfer @Cd in the 'convertvdbpoints' node and I can see my particles correctly shaded in maya.
3) When I try rending with vray (CPU and/or GPU), I cannot get the particles to show up in the render yet I can see them in the viewport just fine

Be that I'm doing this blindly and noobishly, I would love to know what I am doing wrong or if anyone would like to share their workflow/experience on this. Maybe the particles are there but just extremely small and I can't see them, or there is another way to redo the shading so they render appropriately in vray? It just seems strange that I can see it in viewport but not in render. Googling this issue seems to only turn the opposite result where people can render their vdb but it doesn't show in the viewport, or problems with distributed rendering which I am NOT doing.
If anyone has the time to look, I've included a wetransfer link to an example project with scene file and vdb cache up to frame 15. The particles do not show up until frame 10, look through the rendercam and you'll see. Also, you will have to relink the cache since it of course wont be the same file path. Ignore the missing lightning, it has nothing to do with the particle issue.

https://we.tl/t-ozM2HjBBCO

Windows 10
Vray Next for maya2018
Houdini 18

Thank you so much for any help
-Harrison

[georgi.zhekov]

Hello,

Unfortunately rendering VDB particles using V-Ray Volume Grid is not possible.

You can use Phoenix FD to load those and render them using the Phoenix Particle Shader.

You can find more about how the Particle Shader works here - https://docs.chaosgroup.com/display/...+PhoenixFDFoam

Cheers,

[psanitra]

For points export use Alembic ROP, you can load that with vrayproxy and it will render perfectly fine.

[Harrison W]

Thanks for the suggestions! I will try both methods.

Cheers