Foam

[Macha]

Does anybody have an idea about how to create, animate, and render foam?

The kind of foam you get when you brush your teeth, or when you point the showerhead at soapy water, or sprinkle salt on slugs.

I'm thinking particles sticking to each other at a growing radius, or maybe smoke, metaballs, or, hmmm, tricky, and the shading part...hmmm...

Edited March 25, 2011 by Macha

[glomm]

i've done some rnd recently on this topic- foam bubbles in a cup

i've used sop solver with some vops using point clouds stuff inside

here's the result

i'll post hip file later

[pclaes]

I think the above mentioned pointcloud technique will give you the fastest, most controllable results.

In regards to rendering, I would consider rendering clusters of spheres (instances or use ClusterThis) or variations of spheres (2 together, 3 together, 4 together,..) to add more detail. There will be some intersections, but the general movement will probably be convincing enough and perhaps consider animating the bigger hero bubbles as rbds/particle system.

Shading wise, just transparent with a bit of a fake oily sheen to it should be fine, perhaps a bit of falloff added around the edges.

[bandini]

Very cool. I'd love to see how you did that.

i've done some rnd recently on this topic- foam bubbles in a cup

i've used sop solver with some vops using point clouds stuff inside

here's the result http://vimeo.com/21482676

i'll post hip file later

[Macha]

Something along those lines maybe.

Any ideas about shading? Transparent intersecting spheres are very expensive.

foasm.hipnc

[~nature~]

Hi, Macha, I have some idea about it. according to my reading, foam shading should be the typical of level of details.

for the mid and distant shot,usually foam is simulated using particles(birth,kill and convert into water) and finally rendered as mesh.

for the distant part, texture should be sufficient, I remember Houdini 10 has the foam shader shipped with it.

As for the mid one where detail begins to stand out, displaced subsurface scattering shading should do the job.Cellular noise is our best friend regarding the displacement shading. Sphere sim at this point is ok and maybe use metaball to produce the mesh so that the rough surface at the top of the foams continuity could be simulated to some extent.

[ohiro2]

Hi Macha,

Here is the spot I worked on the foam while ago.

It was not animated at all but shading wise,

It is just a volume cloud inside transparent object with noise displacement.

The volume cloud can give you a fluffy look.

Hope this helps

[dynamoanders]

Hi Macha,

Here is the spot I worked on the foam while ago.

It was not animated at all but shading wise,

It is just a volume cloud inside transparent object with noise displacement.

The volume cloud can give you a fluffy look.

Hope this helps

Hi ohiro2.

I´m trying to create a similar thing, could you post a hip file to help me get started with the shading?

Thanks

//Anders

[ohiro2]

Hi Anders,

Here is a basic setup. Hope you will get an idea.

foamsetup.hip

[3dome]

sry for reviving this, but how did @glomm make them stop and move along the "circle border"? unfortunately he never posted the hip, right?