Render Mesh As Volume In Houdini?

[jeffrey_felt]

I'm having trouble getting this to work. I've found other forum threads about doing this in other apps like Maya and Blender but can't get their process to work in Houdini. Does anyone have an example of this working?

https://forums.chaosgroup.com/forum/...mesh-to-volume

"You can render a mesh as volumetric by adding a VrayDistanceTex with a short distance value to the density of some vrayfog (or a filled up volume grid), then adding your geo to the vraydist. If you use the filled up volume/phoenix grid method, you can add displacement. I'm not 100% on the exact steps, but that's how we've made clouds before."

[glacierise]

It's a bit more straight forward in Houdini actually - you can convert the mesh to a density volume using the VDB from polygons SOP, and pick the density volume option. Then pack it and assign the volume grid shader, and it should render

[jeffrey_felt]

How would you use shader displacement in that situation though? I have been making VDB clouds and having trouble getting enough detail in them with the amount of memory I have. Some people seemed to have success using render time displacement but from what I've read that has to be done at the geometry level and not on a VDB.

[glacierise]

The volume grid shader has a displacement input. I haven't played with it much yet - it's not working well with animation. VDB is quite efficient memory wise, you'll be able to squeeze quite a lot of detail. After converting the mesh to a density vdb, try adding a cloud noise SOP - it will give you detailed cloudy distortions that usually look quite good. Find a nice look at low res, then increase the vdb resolution as much as you can, and see if it's detailed enough. Showing the high res in the viewport might be slow, you might wanna just render it

[bdancer]

If you want to replicate the setup like on your V-Ray for Maya screenshot then there is "Volume" input in the material output node of the vray material builder. You could connect "V-Ray Fog Effect" node to it, then just set material opacity to 0.