(Open, Open, Open) [HOU-4574, HOU-4575, HOU-4576] VDB volumes rendering incorrectly

[andrew_cyrmarcoux]

Hi,

reaching out to you regarding VDBs in Solaris.

I'm currently working on a large water sim, and when importing my VDB from SOP, if put in volumetric mode it doesn't renders. But if I put it in volumetric geo, it renders, but way farther in the scene.
I'll put pictures that explains better.



Attached you'll find a file with one frame of the sim and my setup up to date.

Btw I'm working on Houdini 20.5.278 and V-Ray 6.20.24

[andrew_cyrmarcoux]

Can't seem to upload attachment, put it on Drive

[Gosho.Genchev]

Hey andrew_cyrmarcoux ,

We've identified a couple of issues that we'd need to resolve. I'll get back to you tomorrow with more information as I'll need to clarify with the development team.

Best regards!

[Gosho.Genchev]

Hey andrew_cyrmarcoux ,

This will take us a while to resolve - there are two unsupported cases happening there: (1) the non-uniform voxel sizes produced by the Volume Rasterize SOP when generating the VDB based on the camera frustrum, and (2) the "transform" primitive intrinsic attribute not being supported.
I had hopes that a VDB Resample would resolve (1) would help but then (2) popped up, and I have no workaround there.
The only suggestion that I have would be to generate the VDB without relying on the camera frustrum in order to circumvent these limitations.

Best regards!