Please correct me if I'm wrong. Is XZ is the name of plane shown by default as the "floor" grid when you open C3D for the first time? Anyway, whatever that grid is called, if I create a box object, for example, the visible (grid) cuts right through the halfway mark on that box. How do I make one of the parallel faces of the box precisely intersect or align with that plane? In other words, what position properties put the new box on the floor rather than half above and half below it? is this a default that can be set for appropriate objects?