1 basis[0] = (-1. + rr + ss + tt) * (-1. + 2. * rr + 2. * ss + 2. * tt);
2 basis[1] = rr * (-1. + 2. * rr);
3 basis[2] = ss * (-1. + 2. * ss);
4 basis[3] = tt * (-1. + 2. * tt);
6 basis[4] = -4. * rr * (-1. + rr + ss + tt);
7 basis[5] = 4. * rr * ss;
8 basis[6] = -4. * ss * (-1. + rr + ss + tt);
9 basis[7] = -4. * tt * (-1. + rr + ss + tt);
10 basis[8] = 4. * rr * tt;
11 basis[9] = 4. * ss * tt;