Noise in Matte

[Morbid Angel]

Btw I had a look at your scene. So one of the causes of the noise could also be hdr. It had very detailed and contrasted white/black lines that would result it extra noise. I would not suggest to make the texture resolution very high for the lighting dome, instead keep it low and possibly blur the hdr so it contains less sharp detail, less detail less work for the sampling.

For the method I described. If you try it, and look at sample rate element you will see the shadow area below the car is red. This means that there is not enough samples there, where it exceeded the maximum, but more samples were required to create a clean look. I then had to raise the samples to 2/48 at noise 1.0 / 0.002, and got a very clean result but this would probably be quite slow, so you should find a balance

[RockinAkin]

Correct me if I'm wrong but isnt that incorrect? You are using AA to clean up noise that come out from light. Should he not tweakd DMC settings treshold lower or adaptive amount so that more samples get fired by Dome light ? This way his AA should stay low and dome light should render cleaner?

He lowered the AA sampling and increased the Domelight sampling while reducing the DMC sampler noise threshold in his examples... so why do you think he's using AA to clean up noise?

[nomads]

The way I understand it now is....

I use the sample rate element the view where the samples are going.

I want the Red samples to go where I need the detail ie noisy shadows and edges etc.

Blue where there is no detail.


Because this scene has soft Hdri shadows I will need lots of DMC samples.

I should be thinking lower AA and higher DMC

In other words.. Fewer Primary and more secondary, but I need to make sure there are enough primary samples in the detailed areas.

I can use the DMC calculator to refine what the max and min samples are.


If I get the equation right I wont need to reduce the noise threshold to far because the secondary sample will have already cleaned up.



I can also help the scene by blurring and reducing the HDRI map in the light,

[Svetlozar Draganov]

I usually use three methods to clear the noise in scenes.

1. using AA approach - shooting more camera rays will definitely clear noise coming from the lights too.
2. using DMC approach and tweaking directly light-subdivisions
3. using a combination of both - i.e. adding more light-subdivisions and shooting more camera-rays.

In this situation I have lowered AA sampling cause when I changed Noise Threshold value I decided that Max=15 subdivisions are too much to get the results I am looking after.
Since Noise Threshold value in DMC settings is changed to a lower value I do not need such high value for the DomeLight subdivisions and I decreased this value as well.