cmd_viewport

command: /viewport

quick ref:

/viewport [@id] [alignment:_lt|_fi|_rt] [left] [top] [width] [height]

description:

 change main viewport 
e.g.
/viewport							fill all viewport
/viewport 0 0 100 0
/viewport _lt 0 0 600 400
/viewport @0 _lt 0 0 600 400