Having trouble with foam renderings. Starting with the shelf tools and either getting whitewater by default or by adding it afterwards produces foam as a dark cloud instead of anything that resembles foam. I try modifying the colors and that doesn't change anything either. I'm sure I'm missing something simple. Any suggestions?

I have a nice environment light and the water looks good, but the grey cloud does not. It looks like the foam is being created from particles using a VDB node to create a volume. I've heard there are three ways to create foam. One using particles and rendering the particles. Another using volumes like I think I'm trying to do by default. And another using particle normals or something.

Haven't heard from anyone on this topic. Are there tutorials that cover this subject in depth. I've been through the cmivfx tutorials, but the volume method of particles isn't discussed there. I see tutorials on fluids and I see beautiful renders and the authors make it seem like they just hit the render button to get the great looks. I'm missing something critical here.

Can a person hire people to make tutorials on specific subjects? Where would I find someone? Something simple starting with a Flip tank and taking it through to getting nice clear water with foam/bubbles/spray and ocean water with foam/bubbles and spray.

Hey Jeff,

Head into SHOPs, go into your foam/spray material, and lighten up the density. That should make it more wispy.

In terms of tutorials - yeah, I feel your pain. I went through several weeks of R&D to figure out the basics of foam - lots of google work, searching through forums, etc. I'd make a tutorial myself, but I'm not a good presenter at all (trust me, haha).

– Luke

One thing I'm confused on is the same shader gets applied to bubbles, spray and foam if I try to shade the particles in the same Houdini file as the simulation. Is that also part of my problem? Or are they shaded differently somehow and I'm not seeing how?

Jeff Aberle2
One thing I'm confused on is the same shader gets applied to bubbles, spray and foam if I try to shade the particles in the same Houdini file as the simulation. Is that also part of my problem? Or are they shaded differently somehow and I'm not seeing how?

I guess what I mean is. Aren't the bubbles, spray and foam all going to have the same shader which would make foam appear within the water as well as outside the water?

Jeff Aberle2
I guess what I mean is. Aren't the bubbles, spray and foam all going to have the same shader which would make foam appear within the water as well as outside the water?

Yes - and I believe that's intentional, as foam does move beneath the water at times.

what material parametrs u have? for foam