Many times after editing a mesh (cut face, extruding, splitting etc.), I end up with overlapping vertices on other parts of the model (not necessarily near the area I just edited)...I notice this when viewing faces where I see normal points on edges. With the HUD on, I can go in, drag selecting vertices to find ones that overlap and merge to fix with no problem but what I want to understand is...why does this happen and is there a way to know that it is going to happen and where based on the cuts I'm making? Or, is this just something inherent in poly modeling in general that needs to be dealt with?