CAD import with active side

[mvargasevans]

Hello,

I successfully imported .stl files and run simulations. However, when I analyze the data I am not able to select an active side or sort out photons that hit the surface from an specific direction or at least side.

Is there a way to indicate this option in the output file? or achieving that analysis? Regards!

[ChileNeverDie]

have the same problem and looking for an answer...