Splash and Foam Render times

[Teriander]

I can not figure out a way to lower the rendertimes when the buckets start rendering the Splash and Foam. They are increasing the rendertime by at least 10X longer ,and only when the buckets are on the Splash and Foam. Is it possible to tell the Splash and Foam to not create reflections/refractions, etc.?

I can take a screenshot of my settings, just let me know what settings you'd like to see.

[Ivaylo Katev]

the foam and splash really lead to bigger render times and is very easy to become unacceptable. the best method to deal with this is to render them separately and to compose the result, but this is not always possible.
in the cases when you need full rendering you have to keep in mind the main reasons for longer rendering and to give in account the total rays count used during the rendering (this number you can find in the log window of vray)
the most common source of huge delay is the global illumination (GI). it is strongly recommended to avoid GI when rendering foam or smoke. usually instead GI ambient light is used, or few ordinary lights. this works very well in outdoor scenes, for indoor scenes it depends on the scene but also can be managed in many cases.
another important factor is the light source type. if is possible, use simple light types (omni,directionsl,spot, and don't forget to enable the atmosphere shadowing) instead area light. the area light uses multiple rays to calculate the shadows, the simple lights use only one ray.
another source of delay is the image sampler. you can decrease the upper limit of the subdivisions, if there is no noise in the result image, this can give you multiple times acceleration. for the vray auto adjustment algorithm the foam looks like noise and it forces the subdivision count to the upper limit.

[Teriander]

Ivaylo,

Thanks for the feedback, rendering the foam and splash separately and matting everything else is helping. Including disabling GI. I also want to note I think something that had helped was placing a VRaySky in the "Environment" slot for the Foam and Sky. My scene was being lit by an extremely high res HDMI and I think this was contributing to the longer render times. But overriding the "Environment" for just the foam and splashes helped (I think).


Thanks again!