Hi! I'm working over my very first project of a small family house with AC13 educational version for Mac. The problem I met is that the viewpoint of the ground floor plan (elevation 0.0) contains also the outlines of all the elements of mansard floor plan (elevation 3060). That is not a reference, just the "real" elements I can select and operate. The mansard plan is "clean", no elements of the ground plan here. Why does it happen and how could I get rid of the elements that do not belong to specific viewpoint?