Using standard volume medium in Houdini ?

[DamjanMX_1]

Hi,
is there a specific workflow needed for using standard volume medium in Houdini? I just can't seem to get it working, it renders as a solid cube of volume every time. Same VDB exported from Houdini and rendered with standard volume in standalone works as expected.

What am I missing? Thanks.

[galleon27]

In the obj parameters set the "Float Grid 1" to density or whatever float channel you want.

There are a few caveats. Rendering/Loading VDBs in Houdini is a bit slow so usually you convert them to volumes before rendering. That way it loads a lot faster. The problem with volumes is that they are scalar so you won't be able to read color or whatever vector volumes you have.
The only workable way is to write vdb to disk and load it via openVDB in obj parameters since VDBs can be vector. This way you can read vector channels (ex. Cd, Vel, etc).

[DamjanMX_1]

In the obj parameters set the "Float Grid 1" to density or whatever float channel you want.

Screenshot 2022-12-06 231846.jpg

There are a few caveats. Rendering/Loading VDBs in Houdini is a bit slow so usually you convert them to volumes before rendering. That way it loads a lot faster. The problem with volumes is that they are scalar so you won't be able to read color or whatever vector volumes you have.
The only workable way is to write vdb to disk and load it via openVDB in obj parameters since VDBs can be vector. This way you can read vector channels (ex. Cd, Vel, etc).

Thank you so much!

[juanjgon]

Yes, working with OpenVDB files to cache the volume objects is indeed the best workflow. The OpenVDB files are loaded by Octane at the render time, so the scene extraction time is almost zero, and all the Octane volume rendering features are supported.

Thanks,
-Juanjo