Maya VDB rendering in RT

[seandunderdale]

Is this something that will eventually make its way into Vray? Real time rendering is pretty much essential for building out scenes quickly and look devving assets, so itd be amazing if I could build out a bunch of fog and mist assets without having to keep starting and stopping a render over and over.

[damaggio]

I also would like to see this feature …will you get there in 2024 Chaos? Do other softwares have this already other than Redshift ?

[seandunderdale]

I saw some realtime VDB stuff in Blender. This is how I came across the method of downloading VDB fog presets and just fleshing out a scene with atmospherics. It was so fast compared to me trying to build it out from scratch with Maya fluids and vray env fog + noise.

[vladimir_krastev]

Hi, thanks for posting. I can reproduce this issue in a simple scene with V-Ray for Maya 6.10,01. The issue is logged under VMAYA-12535 in our bug tracking system.

[seandunderdale]

If its considered a bug, does it mean it did work fine in a previous version?

[vladimir_krastev]

Hi, the issue is logged for review by the developers. It has not worked in previous versions as far as I know.

[seandunderdale]

Another VDB / volume grid issue....Im finding the viewport runs incredibly slow when you pair Nparticles with an instancer, and VDB volume grids in the same scene. Even if BOTH are hidden and disabled, the viewport is almost unusable. If I delete the volume grid, or delete the INSTANCER, then things go back to normal. Its specifically the instancer, not the Nparticles that slow things down.

But as I said, if I delete either of them, the scene runs real time in the viewport, if both exist in the scene, then its unusable. Ive turned everything I can see down to low, zero or off...Ive exported to new scenes...everything I can think of. If I have either, Im all good, if I have both, Maya chugs to a halt pretty much. Which is frustrating cos Im working on a misty / snowy animation...and my mist and fog is volume grids + VDB and the snow is Nparticles with a snowflake instancer....so both are pretty crucial.

What Im having to do is Ive exported out my snow particle system, and Im progressing the scene...when I want to do a test render of everything, I have to import in the particle system..not ideal.

Im using Maya 2023.3
V-Ray 6 for Maya, update 1.1
(v6.10.01 from Sep 27 2023)

[seandunderdale]

Here is a Maya scene which shows the immense slowdown with instanced particles and VDBs. On their own in a scene, the viewport is realtime, smooth. Add one or the other, and instant chugging....also imagine there is a CAD car, and full cgi set build...so the slowdown is much more than this in a shot. Ive tried turning everything down that I can think of, but nothing gets it back to normal.

I couldnt include the particle cache since it was 2GB, but if you cache to oround frame 350, you should get the effect of the slowdown.

[Muhammed_Hamed]

Thank you for the feedback about interactive rendering, we will consider this for our 2024 plans
About the viewport slowdown with your scene, it seems to be a different issue. We need to reproduce on our end first, I will get back to you on that

Best,
Muhammed

[seandunderdale]

Any improvement on these issues? Having to use VDBs again and theyre so slow in the viewport, and RT does not like them much at all. Cant move or scale them and see any updates