I am quite the newbie to Rhino, so please try to follow my lack of jargon.
I have been shown by one of my tutors through Rhino how to tell if a closed surface/surface/line is inverted (I think that may be the best term). For example, one surface to a hollow cube was pink and the rest another colour. He would then simply flip it, to have the inside and outside(?).
I was wondering how I could turn this function on for Mac?
I have just offset a mesh and I believe that this may be the problem because it is folding in on itself and in all different directions.