Foam extremly slow

[naik]

Hey guys,

is there any option to boost render time when rendering a liquid with foam?
It's unbeliable slow, so that i think i'm missing something here.
Just a simple simulation. Grid Box + Cylinder + Liquid + Foam.
Nothing special at all.
Quality : 20
Total Cells 253440


cheers

naik

[ivaylo.ivanov]

The number of foam particles is important, not the cells count. One option is to render the foam as fog.

[naik]

Hi Ivanov,

thanks for dropping in.

I'm at 500.000 foams particles - is that much?
These are my first tests so far but im really shocked by the rendertime.
The Sim is really fast...

Can you elaborate more the the fog solution.
Although i want to render the water and the bubbles / foam.

[ivaylo.ivanov]

I don't think 500 000 is much. The pool example is with more particles. What is slow for you ? Yo will probably need 2-3 minutes per frame. The foam/splashes can produce overbright colors, which can force the image sampler to do it's maximum samples there. You can check the times with fixed sampler. If you want, you can send the scene to phoenix@chaosgroup to take a look.

[TSR_trix]

Also basic thing is to check are you using refraction on those foam particles? It obviously increase render times if you use refraction. And try to check particles shadows off.
Are you using motion blur? change from Adaptive subdivision sampler to adaptive DMC could help for that.

[Ivaylo Katev]

really it's very easy to overload the foam shader, my suggestion is to start from the lower settings and to rise the quality exploring how it affects the render time. to be clear what causes the delay, test to render with fixed image sampler as well.

[naik]

Thank you guys, that's a good start i think.
I gotta do some decent tests...

cheers
naik