Weird splotches

[vermu]

Hi,

I have been suffering from these strange artefacts as long I have been using gamma 2.2. If you zoom the pic abit you can see those splotches on the door and pilar etc. I am currently using gamma 2.2 with exponential color mapping and I am saving the images as 8 bit depth tiffs. Those splothes occur only on the shadowed areas. This is just one problem spot. Can you what causes that kind of problem?

Edit: I rendered a small area and saved it as 16 bit tiff. It seemed to take away alot of those artefacts. So I guess it was color grading issua caused too small bit depth.

[Drawehn]

These splotches are caused by the irradiance map settings. The shadowy areas don't get anough light rays bouncing on them to achieve smoothness.

In those cases I usually put the HSph. subdivs up to anywhere between 40 and 100 (the higher, the smoother but the more loss of detail. Higher setting also means higher render times).

THe other option is to increase your irradiance map settings.

Hope that helps.

[vermu]

Ok. I was using 70 Hsph subdivs. I'll test with higher settings. I noticed that using 16 bit depth removed the odd color errors but left the splotches. Is it possible to use different hsph values for different objects if I render the scene in one go?

[Morbid Angel]

You dont need to. Set your prepass to be -3/0 and set your ir map subdivs to 150/100 and you will get a pretty clean image, though may take longer to render but you can work backwards from those settings.

[vermu]

I found out that for my scenes ir map subdivs 150/50 and prepass -1 -4 worked pretty nicely. I have a clean enough image and render times are managable. I am using lightning where most of my building is in shadow or low light. I just thought that if you have to go beyond 100 with irr valueas there's something else wrong in the scene. Thanks for the great tips.