Is there a way to use OpenVDB volumes in the same way (or better) as using the VEX Volume Procedural?

I thought they were the same already?

No, they aren't the same. Vex volumes use the whole bounding box, whereas OpenVDB uses sparse voxels. At least that's what I've understood so far.

Sorry, I meant that they are the “same” in the sense that it should flow through the render pipeline in exactly the same way in response to your question. Say you had something working for native volumes, and if you replaced those native volume primitives with VDB primitives, then it should still render the same way.

Oh, yes in that respect they are the same. But, the VEX Volume Procedural creates the old kind of volumes at render time. I don't think there is a procedural that will create OpenVDB volumes at render time (yet). Unless someone has written one that they would like to share.

Sorry, I missed the *VEX* part of your description.

There's no way to create an openVDB volume or houdini geometry volume at render time aside from writing your own VRAY_Procedural in the HDK. The VEX volume procedural doesn't allow the creation of a VDB volume (or a houdini volume for that matter) - it's a way to specify a volume as a cvex shader that is point sampled by mantra's volumetric ray marcher. No intermediate voxel storage is created by the VEX volume procedural.

You could use the delayed load procedural for VDB and for houdini volumes if you have a .bgeo on disk storing the volume and wish to load it at render time.

Andrew

Is there any way to use the VDB narrow band as the the “bounds” of the Vex procedural volume?