@DATAstrm I used some clever trickery in Blender to create a room where when the viewpoint is in the room all the walls, ceiling are visible. When outside the room the walls, ceiling and objects between you and room automatically disappear and reappear, but they still cast shadows. I used the same "Is Camera Ray" + Transparent into a mixer that you point to, but also a Geometry:Incoming + some other math nodes to achieve the magic disappearing act.
I think SH3D is wonderful, and very good for figuring out your space. But if you want ArchViz grade imagery, or clever tricks like you describe, I just don't think Emmanuel has the bandwidth to implement every feature people dream up. You need to either move to (very expensive) commercial products, or you have to learn how to beat blender into submission. I chose option 2.
