Hi EDDI -

re: window - in MoI if that's a solid I guess you'd say you're looking AT the window. There isn't anything built into MoI that considers one outer side of a solid to have a different property than the other side. The Flip command previously referenced only does something to a surface object, it doesn't do anything to a solid. A solid is automatically oriented to have its surface normals pointing to the outside region of the solid volume.

Similarly a "show backfaces" function will only show something of note on open surfaces, a solid doesn't have any visible backfacing polygons unless your eyepoint is located inside the solid itself which would then show all parts of the solid as backfaces.

- Michael