0 0 0 a
0 1/2 0 a
1/2 0 0 b
1/2 1/2 0 b
0 0 1/2 c
0 1/2 1/2 c
1/2 0 1/2 d
1/2 1/2 1/2 d
x 1/4 z e
-x 3/4 -z e
x y z f
-x y+1/2 -z f
-x -y -z f
x -y+1/2 z f