Problem with splotches

[fAEkE]

I have some strange splotch issues. The scene is lit by a vray sun and sky. 2000 LC subdivs and high preset with 200/50 for the IM. With those settings I don't understand why there are any splotches.. anyone got a clue?

[Morne]

in Irradiance tick "check sample visibility", also if your wall is only an extruded line, try making it a thick box (make your wall the actual thicknes of a wall, maybe 230mm)

[fAEkE]

Ah, it might be that. I don't do the modelling, and the room has no thickness. I need to fix that and see if it solves the problem.

[Deflaminis]

Also make sure part of the counter there isn't poking through the wall, I've seen this happen when geo intersects.

[fAEkE]

Rly, hmm.. I had another problem like this in another interior today, and there it probably is an issue with intersecting geometry. I didn't think that was a problem tbh, I almost always put cabinets and such so that they intersects the wall a bit.

[kriscabrera15]

i would also try using brute force instead of LC. I have had better luck with brute force

[fAEkE]

I like LC better. Rendertime is greatly reduced and in my opinion it looks better. In these soft white interiors that I work with anyway. Thanks for the tip tho

[3DMK]

When doing this sort of scene setup I ALWAYS put a box/wall at least 100mm thick covering the outside wall. This prevents the sun hitting the backside of your internal walls. If the sun hits the backside of a one sided wall then vray will end up rendering the outside light samples on the inside causeing exactly your problem.
This is a much better method than using the new Re-trace option which slows things down.

Hope this helps

[fAEkE]

Thanks guys. I remember discussing this a couple of years back and after that I have always modelled with thickness myself. The reason why I did not remodell the house was because I thought this problem was fixed, has been a long time since I experienced it and I had forgot about it.

Anyway, what is re-trace 3dmk? And another thing, how does this issue affect e.g. Leaves with 2sided material? The leaves in this case has no thickness, shouldn't that cause the same problem?

[Morne]

retrace is a new feature in LC in VRay version 2.0. It sometimes solves the kind of issue you have
look at the docs on spot3d for example pics of retrace under LC

[Deflaminis]

We did a commercial for Airwick not too long ago that had this problem on the wanes cotting on the walls in the bathroom. To fix it, we used a "subdivide" modifier on the mesh which helped vray subdivide it and the light problems went away. It's hard to say what will work without the scene, but a subdivide might help a bit, and doesn't destroy anything or become permanent if you don't want it.

[fAEkE]

Thickness on the wall fixed my problem, but thanks for the tip, I'll keep that in mind