Hello Rich,
thanks for your reply.

The models are very complex. I would have to paint all the surfaces one by one? Or is there a function to automatically paint all surfaces that are visible from inside a room?

Best regards.

Hallo,
I'm new in this forum and maybe someone can help me.

We do acoustic ray-tracing calculations and the software can import sketchup-models. For the calculations we need a model which only contains 2d surfaces that are directed inside the room. Sadly most models from architects have a lot of planes that are "outside the room" e. g. walls are modeled as 3d-objects and we only need that surface that is part of the inner shell.

My question:
Is there a way or maybe a plugin that select all the surfaces that are part of the inner shell of inside a room? Or contrariwise select those surfaces that are outside the inner shell?
Thanks in advance best regards
Ralf