GI Causes see through of geometry

[Joelaff]

I have a scene which is very similar to many scenes I have been working on on this project. I have been using the same objects, and the same lighting techniques throughout.

Now, on this one scene when I enable GI I can see through my object. The alpha is still solid in the renders, but the RGB shows the objects behind my object (which are hidden to the camera) through my object. The effect is subtle, as it is only in the GI. It is worst with Brute Force GI.

I have no clue what is causing this. I tried adjusting secondary ray distance. I tried upping subdivs and samples, etc.

The objects I am seeing through it are UV camera mapped and have a VRayMtl applied to them with simply a diffuse map using the camera mapped UV (basically a ground plane).

Anyone seen anything like this? Any thoughts on how to get rid of it?

Thanks!

[new.ages]

Sounds like you have the bitmap in camaramap set to environment screen-space - try to set it to texture space

[Joelaff]

Brilliant!

Yes... That was the issue...

Now, I am curious why, technically that would make the GI come through FG objects from BG objects, because the camera mapped texture was only on the BG objects. I guess it has to do with how VRay samples the GI textures.

Anyway, thanks.