Next CPU IPR - Volume Grids Not Rendering?

[mitchgates]

I'm running into a strange behavior in Next CPU for 3ds Max 2019 while using the IPR with Vray volume grids. For some reason they don't render at all in IPR mode, but if I do a full progressive render they show up fine. If I use Next GPU they render fine in IPR mode. Running Next 4.02.04.00003. Any ideas?

Thanks.

[matanov]

This is a current limitation of the CPU IPR - it doesn't support volumetrics (env fog too). You can switch the render mode of the volume grid to "volumetric geometry" as an workaround.

It will be fixed in a future release. Sorry for the inconvenience.

[vlado]

What Peter said - updating the volmetric rendering structures for the CPU renderer is a bit involved and we are still working on it.

Best regards,
Vlado

[JonasNöll]

Hi, this hasn't been adresse yet or? I'm running into the same issue that VDB's don't show up in IPR, just in a full rendering.
Stuff generated by Phoenix seems to show up in IPR though...

Edit: I found a video for Maya where it seems to work in IPR. Is that something 3ds Max specific?
https://youtu.be/A7wOhfwyNN4?t=182

[georgi.zhekov]

Hey Jonas,

Should be working with VDBs in IPR as well. Are there any errors in the log? Which version of V-Ray are you using?

Does it happen with any VDB file or just with a specific one? Can you send over the scene so that we can take a look?

Thanks!

[JonasNöll]

Hi, indeed I just tested it in VRay 6 Update 1 (latest official version) and there it seems to be working. The project where it doesn't work has to be setup and rendered in an earlier V-Ray version (I believe V-Ray 6 Hotfix 2) and there it doesn't seem to work. So this functionality to render VDBs in IPR was added sometime inbetween Hotfix 2 and Update 1?

[georgi.zhekov]

Ah, yes - this is it. The support for IPR was added in V-Ray 6.00.20 hotfix 3. You can find the release notes here - https://docs.chaos.com/display/VMAX/V-Ray+6

In case you can't use the newer version due to the project being locked to an earlier one - if you have access to Phoenix 5.10, maybe you can use a Phoenix simulator instead of a VRayVolume grid to load the cache - this way the IPR should be working.

Cheers!

[JonasNöll]

Ok awesome, that explains it. Great that it is working now in the current versions
Then I will try out the approach with Phoenix or just setup the scenes with the current version and save them down to the earlier version.