Milling, CDL-V3 allows the simultaneous viewing of your drawings from 4
separate angles. The 4 views are all active windows, so objects can be
selected from any of the windows, to make geometry or chains. You
can even draw lines from a point in one view to a point in a different
window. Any of the views can be expanded into the main window, and the
small window's viewpoints will automatically be adjusted to suit.