[Resolved] Volume Grid Cache not loading VDB

V-Ray V-Ray for Houdini Issues
1

Hi,

i try to load a VDB fog and i give me an error.

I try also with an old scene i found on the beta forum and it’s not working, (https://drive.google.com/file/d/1K2C…_jUUEcIVD/view)

Have nice day.
Best Regads
Daniel

2

Hey there, use the File SOP for VDBs and native volumes. We’ve kept the VVG Cache for Phoenix FD Aura files only.

Hope that helps!

3

hi,

thank you for your response,

so i can directely load a vdb via the file Sop or directely a vdb on the fly ?
and for the material i put the volume grid shader ?
can you have a small scene exxemple ?

my output is black when i try.
Thank you for your help.
Best regards
Daniel

4

Hi @dpotuznik , you can load a vdb through FileSOP but should assign a VolumeGrid shader in order to get something rendered. V-Ray isn’t assigning a default shader to volumes like for the geometries.

5

Hi,

Thank you very much this is perfect.
i foud my mistake , the Cd attribute was missimg from my VDB and it failed to render.

Thank you again for your help.
Best Regards
Daniel

6

By the way, just a quick heads up - the Fields tab on the Volume Grid Shader expects vector fields to be represented as 3 separate float fields. E.g. ‘vel’ should be ‘vel.x’ , ‘vel.y’ and ‘vel.z’ when you middle mouse button click on the node holding the volumes. The same goes for Cd. Same goes for rendering the native houdini volumes. Technically speaking it’s not a requirement that you convert them to VDBs and cache them to disk but it makes things more efficient. Otherwise, we bake the entire volume to the VRScene file instead of reading it from disk.

This may cause some confusion so we’ll update the documentation ASAP.

Best regards!