(NOISE) Problems with Corona sun for Cinema4D

[Giuseppe Marino]

Goodmorning everyone.
I have a problem!
As you can see from the attached photos, I have a scene where I set the sun of Corona with the sky of Corona, so far so good.
When I go to turn off the sun with the lightmix, a very high noise appears, it does not go away even with a clean scene at 2.5%.
I thought it was due to the size of the sun, but I have done various tests and it persists with both a sun at 1 and 10 in size, or different.
The Corona version is 8 (DailyBuild Feb 2 2022), but it also happened with the previous one.
The Cinema version is R20.
I also posted in the forum, but still no reply!
Has anyone else had the same problem and solved it?

[TomG]

This is expected - because Corona intelligently decides which light sources need more processing in every area of the scene (adaptive light solver), in that area the sun is given more focus than the other light sources because it is by far the largest contributor and noise in the other light sources is not visible underneath it.

This leaves the other light sources more noisy if the sun is removed. Often if you intend to use LightMix it is best to keep all light sources at a similar intensity if you are planning on making large changes (such as removing a light source that is much much brighter than others) once you get into LightMix. It means the Beauty looks strange, but you won't need it anyway 🙂

(In a similar way, to fully control color, it is best if all light sources are white, again because you will adjust it in LightMix and keeping them white gives you the most control in LightMix and lets you make the most adjustments).