z:
0
0

c:
1 0 0
0 1 0
0 0 1

P0:z-c
1 0.5 0
0 1 0

T0:c-c
1 0.5 0.5 
0 0.5 0 
0 0 0.5

T1:c-c
0.5 0 0
0.5 1 0.5
0 0 0.5

T2:c-c
0.5 0 0
0 0.5 0
0.5 0.5 1