VRay dark Blotches

[monrosm]

Hi

 

I am quite new to the software and am sure there is a quick answer to this but so far it has eluded me on the forum posts. When rendering I seem to get dark blotches all over a smooth surface, can't figure out what it might be. I have attached images showing the blotches (on the walls).

 

The second image shows it better!

 

Any help is much appreciated.

[Bruce Hart]

check that you do not have coplanar faces.

[DavidR]

This is low indirect illumination settings. Try irradiance medium preset and see if it goes away. You can then decrease the hsubdivs from -3,-1 to something like -4,-2, etc.

[Bruce Hart]

I'm not trying to contradict David here - but I would be surprised if that was due to low IM/LC settings. GI splotchyness is not usually that dark, and the fact that it only seems to be mainly affecting the walls would seem to indicate there are some face problems. In the first image you can see artifacts on the walls, but the linen on the bed is pretty clean. If this were low GI settings, the problem would be all over the place?

 

I'm thinking that there are bits of geometry that have been cloned on top of themselves, or parts of the model have been imported twice. Maybe you've got this part of the boat from a CAD file somewhere and it has a double surface? There seems to be plenty of light getting in the space. As a quick fix you could try changing the secondary rays bias to 0.01 in the Global switches tab.