Noise Fireflies in Foam/Splashes?

[markus_s_cg]

Hi

I am getting bright noise in my image in the foam splashes. How can I get rid of it? I am rendering foam as bubbles and splashes as splashes. I tried lowering the Highlights Strengths on the shader helper, but it didn't help. I am rendering with a HDRI (Cosmos Day 25) Dome in Vray 5, and I'm using Chaos Phoenix 4 ADV for 3ds Max 2021 / V-Ray 5.x,
version 4.41.02 Nightly. In this new render it even looks like I'm getting different results in some buckets, even though it is all on the same node (DR is disabled)?






Any tips or help would be greatly appreciated.

[georgi.zhekov]

Hey,

Does it help if you disable the Render as geometry checkbox or if you disable the Volume light cache?

[markus_s_cg]

Hmm, thanks, I will try that...

[markus_s_cg]

I tried turning off both. Seems like it has helped, but only a few buckets rendered locally so far.
I think it was the volume light cache, not the geometry. It seems to render quite slow, even slower than before. Any tips on how to speed it up a little without using volume light cache?

[markus_s_cg]

Lowering the exposure on the Vray Camera helped a bit with the speed. The image was rendering a bit overexposed and in the screengrab above I had lowered the exposure in the VFB.

[georgi.zhekov]

You can try to adjust the Probabilisitc samples in the Atmosphere settings here - https://docs.chaos.com/display/PHX4M...phere+Settings

Try lowering the samples a bit. Note that not always the lowest number will render the fastest, but try 5, try 10 and so on.

Also if the Volume light cache is the culprit - you can also try enabling it back on but use lower value for example. Try 0.5 for example, if it is still bad, lower it more. If the checkbox is on, even a value of 0 should contribute a bit to the render speed.

[markus_s_cg]

Thank you for the input! That seems like very helpful things I can test.