My only issue is that Sketchup always has two faces per quad, there doesn't seem to be the concept of a back-face. Consequently all the meshes I export have two faces, of which I definitely dont want one of them. However I dont know of any way of excluding the back-faces, since I find it difficult to even define one - I "know" its the face that is "inside" the 3d mesh object, but other than looking at its Face Normal in relation to the objects centre point (doesn't work with non convex bodies particularly) I find it difficult to hit on an idea for excluding them.
Does anyone have any bright ideas ?