Select Inside or Outside surfaces Only of shelled object

Hello, is there a command to select the internal or external surfaces of a shelled object?

I’ve a complex shelled solid and would like to offset the outside surface (made of multiple surfaces) of my solid but keep the inside surfaces intact. Would be nice to be able to select only inside to.

thank you

the short answer is no…

however most shelled objects have a connector surface that connects the inside and outside surfaces (typically along the parting line) . If you extract just that connector surface essentially exploding the model into 3 pieces (inside, outside, and connector surface) you can then easily isolate inner and outer surfaces-

@french_craftsman, @theoutside - you can try the attached Python script - use RunPythonScript. I have not actually run it in Mac Rhino, but I think it ought to work. (24.9 KB)
I think the command line options are self-explanatory but shout if you need help.


@theoutside & @pascal thanks between you two I made it work. I confirm that works on mac.