0 0 z a
0 1/2 z+1/4 a
0 0 z+1/2 a
0 1/2 z+3/4 a
x y z b
-x+1/2 -y+1/2 z+1/2 b
-y x+1/2 z+1/4 b
y+1/2 -x z+3/4 b
x -y z+1/2 b
-x+1/2 y+1/2 z b
-y -x+1/2 z+3/4 b
y+1/2 x z+1/4 b