4 -.75 -.75 .75 .75
          .5          0           0           .2     .25      0  .4
         .25          0           0         -.25    .125      0  .0
           0          1          -1            0       0      0  .2
           0         -1           1            0       0      0  .4


   .70710678  .70710678  -.70710678    .70710678       0      0  .0

          -1          0           0           -1       0      0  .0
// rotations
 90
180
270



