Quote - > Quote -  If the wall is actually set invisible in properties then it should not show in the final render.  Maybe you just set part of the wall to invisible.  Sometimes walls are made of several bits.

Love esther

The problem with doing that is that it will affect the accuracy of the IDL, at the very least.

Serious for a second if that is even remotely possible.

Couldn't you move the wall out in Z and drop some primitives in place around the edges to plug the new gaps as long as they don't show in the camera-render view and not affect the IDL accuracy. 

But my question would then be how "light" or air-tight would it really have to be to trap the IDL bounces?

Gary

"Those who lose themselves in a passion lose less than those who lose their passion"