foam take very very long time to render.

[lzmihich]

I am using the foam submarine presets , motion blur is vray.
all default.Scale is maybe the issue but resolution seems to be in control.
It takes hours to render the tiny region where the foam is.

[Ivaylo Katev]

all the frames or only one? we found situations, where the acceleration tree fails to build and single frames are renderd in about 100 times longer time than their neighbor frames with the same count of particles. this issue is fixed, so you can try with the nightlies.

[lzmihich]

Actually I was rendering a single frame only, it was stuck, and sometimes even Light cache with very
few samples , like 200 would get stuck too.
maybe I'll have to be more consistent about the scale of my scenes and
even with the unit's scale in Max.
I don't really know How to set up the perfect size for foam and splashes for instance..
I get confused as I work with meters ,and Vray seems to like milimiters.

P.S : About the nightlies.
Forgive my ignorance about it, but what exacly are the nightlies ?
are they patches to fix bugs?,if so, Where can I download them ?

[Ivaylo Katev]

the nightlies are builds of the intermediate development stages of the software, they include the latest fixes, but are in general less stable because the development changes.