Noise around lightsource workaround again?

Started by Hannes, November 15, 2016, 10:58:33 AM

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Hannes

I know this problem has been mentioned a lot of times. I have a lightsource inside a localised cloud which represents fog. There's a lot of noise around the light. I tried everything: disabled "glow in atmosphere", increased the samples in the atmosphere's quality tab, increased the quality in the cloud itself (this helps a bit, but rendertimes explode!).
Now here is my question: is it somehow possible to "disconnect" the light from the cloud? I don't need any glow, only the illumination of an object.
Using another (invisible) object with a selfilluminating shader instead works somehow, but doesn't look as good as a real light.

Dune

Soft shadows of the light itself, or no shadows at all? I know it's a tough one.

Hannes

Quote from: Dune on November 15, 2016, 11:14:05 AM
Soft shadows of the light itself, or no shadows at all? I know it's a tough one.

Thanks Ulco. No, unfortunately the shadows don't seem to have any influence on the noise. This is really annoying. Using a selfilluminating object is really a foul compromise. I don't want to do that, but the noise is inacceptable as well.

Matt

Sunlights can be enabled separately for illuminating surfaces and atmosphere/clouds. Unfortunately this option hasn't been added to local "light source" nodes yet. I'll add this for v4.1.

Larger light sources have less of a central hot spot. That will reduce noise.

Another option is to render your scene in two layers. One atmosphere/cloud layer and one surface layer. If you set this up with Render Layers, you can do the setup just once to exclude certain lights from all your atmosphere/cloud renders. Of course this means you have to composite the renders afterwards.

Matt
Just because milk is white doesn't mean that clouds are made of milk.

Hannes

Quote from: Matt on November 15, 2016, 08:07:20 PM
Sunlights can be enabled separately for illuminating surfaces and atmosphere/clouds. Unfortunately this option hasn't been added to local "light source" nodes yet. I'll add this for v4.1.

Larger light sources have less of a central hot spot. That will reduce noise.

Another option is to render your scene in two layers. One atmosphere/cloud layer and one surface layer. If you set this up with Render Layers, you can do the setup just once to exclude certain lights from all your atmosphere/cloud renders. Of course this means you have to composite the renders afterwards.

Matt

Cool!! Thanks a lot, Matt!

Dune

Thanks, Matt. Great option about the distinction.

Hannes

Quote from: Matt on November 15, 2016, 08:07:20 PM
Larger light sources have less of a central hot spot. That will reduce noise.

Yessssss!!!! That helped! I changed the source radius from 0 to 1 and increased the light's strength. The more you increase it the more noise shows up again, but it's barely noticeable. Great!!
I thought I had to wait until v4.1... :)

bobbystahr

Good thread, great work around Matt and woo hoo for the 4.1 addition....
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist