Hello All,
I'm totally new to Houdini(currently using apprentice to learn) and I was playing around with an idea but having trouble understanding how certain things work with volumes:

Basically what I'm trying to do is use an obj of a model that I import in Houdini to generate 2 volumes a) scalar density volume b) a “color” volume which is basically a vector volume(3 scalar volumes) that uses the vopsop to extract color attributes and assign them to the vector voxels. I'm using an isoOffset to create the basic density and a volumeFromAttribute to create the 3 volumes from the points and store the color values in the voxels. I'm then exporting these volumes as VDBs and using them in C4D(with Arnold) to essentially render a colored volume version of the original model.

The idea here was to pass the volumes into the pyro solver and use turbulence or any other microsolver to advect the volumes thus creating the illusion of a solid mesh evaporating into smoke.

I was already able to to render a proper colored volume with C4D and Arnold although having some issues getting the surface to look smooth but I'm not sure how to advect the color vector volume(or the 3 volumes representing the RGB components) with the density field. I know that rest fields are supposed to do that in order to support mapping textures but I can't figure out the best way to basically just copy the movement of a specific field(like density) to other fields and volumes since the pyro solver seems to only act on specific set and type of predefined fields(although I know that these fields can be bound to any volume name as long as it's one of the fields it's using for the solution).


Is there a way to do this in Houdini?

Regards,
Ihab

YAY!!! I figured it out…it was much simpler than I thought it would be.
The solution was simple volume VOP: sample the R G B fields positions using the pyro solver generated rest fields and assigned the RGB values based on the advected rest volume.

-still have a few problems: the rest field/volume seems to jump back to the beginning half way through the sim(not sure if I did something wrong)….any specific advice on how to setup and use the rest field?

-my original RGB volumes were setup with static bounding box, is there a way to dynamically resize an isoOffset volume while keeping the voxel values and positions the same?

Attached is a very low res(both render and volume) sample of the output from C4D/Arnold