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