1 basis[0] = (1.0 - rr) * (1.0 - ss) * (1.0 - tt) / 8.0;
2 basis[1] = (1.0 + rr) * (1.0 - ss) * (1.0 - tt) / 8.0;
3 basis[2] = (1.0 + rr) * (1.0 + ss) * (1.0 - tt) / 8.0;
4 basis[3] = (1.0 - rr) * (1.0 + ss) * (1.0 - tt) / 8.0;
6 basis[4] = (1.0 - rr) * (1.0 - ss) * (1.0 + tt) / 8.0;
7 basis[5] = (1.0 + rr) * (1.0 - ss) * (1.0 + tt) / 8.0;
8 basis[6] = (1.0 + rr) * (1.0 + ss) * (1.0 + tt) / 8.0;
9 basis[7] = (1.0 - rr) * (1.0 + ss) * (1.0 + tt) / 8.0;