Adjust the shape and size of a beam system. Add openings where necessary.
 Mode panel
Mode panel 
  (Edit Boundary).
 (Edit Boundary). 
 Adjust panel
 Adjust panel  
  (Reset System).
 (Reset System).  Mode panel
Mode panel 
  (Finish Edit Mode).
 (Finish Edit Mode). 
Beams of a system will remain attached to their original supports until the beam system is reset.