/R; return exp(-0.5*p) * 1.0/(32.0*sqrt(15.0)) * (20.0 - 10.0*p + p*p)*p;            }
    float R42(float r) { float p = 3.0*r/R; return exp(-0.5*p) * 1.0/(96.0*sqrt(5.0))  * (6.0 - p)*p*p;                      }
    float R43(float r) { float p = 3.0*r/R; return exp(-0.5*p) * 1.0/(96.0*sqrt(35.0)) * p*p*p;                              }

    float P00(float x) { return 1.0;                                  }
    float P11(float x) { return -sqrt(1.0 - x*x);                     }
    float P10(float x) { r