VRayVolumeGrid Lacks Motion Blur

[noouch]

I am rendering a FumeFX sim cached as VDB with the VRayVolumeGrid, and am getting very pretty results, except for one thing: motion blur appears to be nonexistent. No matter how I twist the settings I can't get it to show any effect, even with huge multipliers. I am caching velocity out of FumeFX so the information is definitely there.

Also, I can't seem to get any displacement using Volume Geometry mode, which is needed since I need deep output. I am working around this currently by rendering the displaced version in Volume mode and a deep pass with Volume Geometry, but this may cause trouble down the line.

Is this fixed in later versions? I am using using 3.60.04.

[georgi.zhekov]

Hey,

You can get a latest stable build from https://nightlies.chaosgroup.com (use the account for chaosgroup.com) where those things should be working.

Different applications use different channels and names for them. When loading f3d/vdb files, VRayVolumeGrid tries to automatically make the conversion to the supported channels. If a channel is not mapped by default, a channel can be manually set in the Input rollout on the Modify panel by clicking the Browse [...] button under Preview & Render Cache Path and choosing 3rd Party Channel Mappings from the pop-up menu. From there you can choose the appropriate velocity channel.

If you can't see the builds, drop an email to support@chaosgroup.com with a link to this thread.

[noouch]

Hi Georgi, rendering with the nightly fixed the motion blur for me. I have noticed that Z/Y seems to come in flipped by default with FumeFX 5 caches, though the Fume 4 caches seem correct.

I have however noticed something else: when rendering deep images with the VolumeGrid object in Volume Geometry mode, the samples all have infinite color values, and solid alpha, so the renders are essentially unusable within a larger workflow. The beauty image looks fine, just the deep output is messed up.

Edit: Rendering using the FumeFX Fusionworks renderer with the VRay Deep Data option also produces the same infinite color and solid alpha values in the deep render.

[georgi.zhekov]

Hello,

Can you send me a scene where this happens?

Thank you,

[noouch]

In reproducing the issue in a blank scene it seems the problem may be on our end. I'll investigate further.