If I have artifacts I check my render elements (diffuse, lighting, GI,..) where it comes from. Did you check them and give you a clue?
hmmm i did now, and all elements look OK except for VrayLighting (in this one the bottom of the sofa is black) … so u guess something wrong with the lights then?
Its something with the lights, but im not even sure there is anything wrong? The scene is lit mostly with vrayies and when I move them the “shadow” on the sofa changes… If i change the material on the sofa the problem is still there, (but less noticable with a light material). I have re-smoothed the sofa, and applied a turbosmooth as well. Still there. So… is this just a shadow? I think it looks way too sharp and dark?
It sounds like a problem with the model. Have you checked for any overlapping faces? If you stick another sofa model in the same position with the same materials, does it have the same problem?
Thanks for the input - I thought so too, but I put a box-object there instead, with a noisemodifier and turbosmooth, and it had the same sharp shadows. Im starting to think the ies-file is bad. Using “override” shape in the lightsettings and making it a small sphere the problem seems to be reduced, but then I also loose the nice light distribution right? Im out to lunch, will try some more later today.
Is there any chance the apartment has rising damp in it?
Thats probably it… gonna let the client know that he is about to sell apartments with moisture problems 
I cant spend any more time on this… since everything else look OK ill just photoshop the sofa in the finals. Strange though, havent had that one before.
Increasing the shadow bias of the light might have helped a bit.
Best regards,
Vlado
Thanks Vlado. I tried that… Changed the bias from 0,2 cm to 10 cm and it didnt make much difference.
Ok, then I don’t know If you feel like it and have time, you can send the scene to support@chaosgroup.com so that we can check what’s going on.
Best regards,
Vlado
If it has a normal map it could be the gamma is wrong giving shading errors as it turns away from the camera.
It looks like the similar issue I had with some cushions. It ended up being a limitation of the bump map - having a low blur setting on the bump bitmap makes the problem worse so try turning it back to 1 if you have lowered it.
http://forums.chaosgroup.com/showthread.php?83560-Bump-map-issue
It doesnt have a normal map, but the problem went away when I turned off the bumpmap! (just a black and white jpeg).
Yes Chris! Thats it! The blur was set to 0,1. Changing to 0,7 gets rid of the shadow!
Huge thanks guys!
K
its the “roughness” of the surface produced by extreme bump as you guys already figured out.
