Selection external surface

Hello

Is there a method to select all external surfaces of a part / assembly?

At the moment i use a journal where i rotate the displayed part in different views and grab the visible faces. Often there are interferences / undercuts that are not selected properly. Is there a better selection method than mine or even a possibility to check whether surfaces are external?

Thank you and best regards

If you have access to SNAP, there is a property Body.Shells that gets all the shells of a given body. Then, each shell has a "Type" property that could be "Inner" or "Outer". A typical solid body has a single outer shell and perhaps some inner shells that define internal voids. So, you can look for outer shells, and then get the faces of those shells.

For an assembly, I don't see an easy way to proceed.