scale 1.0
boundary -10.0 -10.0   10.0 10.0

line  0.6 0.8   0.6    -10.0  10.0    10.0  10.0
line  0.6 0.8   0.6     10.0  10.0    10.0 -10.0
line  0.6 0.8   0.6     10.0 -10.0   -10.0 -10.0
line  0.6 0.8   0.6    -10.0 -10.0   -10.0  10.0