I am doing some MR testing for a scene. Basicaly, its a wall (poly) with a hole in it. I use a spot light which is outside the room to light the interior.

As you can sell on the picture below, I somewhat have x-ray vision since I can see the thickness of the wall. How can I fix this?

I have tried in maya software renderer and the problem isnt present. But I have to use MR since I need Global illumination and the window will be filled with a stainnedglass.

Thanks!