Major rendering errors with Bifrost... step size?? Volume padding??

[aaronfross]

Hello,

I am taking baby steps with rendering Bifrost volumes in Arnold and have immediately fallen down on my face.

See the attached screen capture... major rendering errors here. Looks like the sort of thing that happens with bad settings for Step Size / Volume Padding.

However, I cannot find any settings for Step Size or Volume Padding in the bifShape node. I tried changing the settings in the source geometry mesh shape node that emits the volume, but it's not helping.

Viewport 2.0 looks fine. It's definitely an issue with Arnold. Looks like an epic fail, but maybe there's something I'm missing???

Caching to VDB didn't help.

Please advise,

Aaron

[aaronfross]

Also, I just got a fatal error and fast exit when merely closing the Arnold Render View.

It does not appear to me that the combination of Maya, Bifrost, and Arnold is stable or usable, but I desperately want to be proven wrong.

[aaronfross]

I struggled through the VDB caching procedure in Bifrost; sample graph was wired incorrectly. But eventually got it cached. Did not solve the Arnold rendering error, so I'd say it looks more and more like an epic fail.

[Stephen.Blair]

Are you using mesh_to_volume?

We haven't had any support cases about bifrost yet, so I haven't spent much time with Bifrost.
Bandwidth seemed to help a bit in my first test:

I'll check in with the devs on Monday and see what they say.

I do see this in the Bifrost release notes, so there some problems using bifrost graphs for volumes...

ARNOLD-118 Dark blocky artifacts visible in rendering some Bifrost volumes

In some cases, Bifrost volumes coming from the graph render in Arnold with blocky artifacts. OpenVDB files loaded using the graph can have the same issue. As a workaround, write your volume as OpenVDB files, and render it using the Arnold Volume node.

[aaronfross · Accepted solution]

That's crazy, I just submitted a reply here and the website deleted it.

I'll try again.

Thanks, Stephen, I didn't give you enough information.

I'm rendering an Aero simulation, not a mesh to volume.

The issue is my ignorance of Bifrost. I need to use a set_Arnold_volume_settings node.

So it's fixed, YAY!