isosurface { //-------------------------------------------------------------

  function{
    f_flange_cover(
       x,y,z,
       0.004, // spikiness,
       10,    // inverse size,
       0.53,  // flange, (1 = off)
       1      // threshold
       )                                                                       
  }          
 contained_by {sphere {0,1.5}}
 threshold 0.01 
 accuracy 0.00001
 max_gradient 5
 
 texture{ pigment{ color rgb <0.9,0.4,0.7>} 
          finish { specular 0.1 roughness 0.1 phong 0.2 }
        }
 rotate<45,45,0>
 scale 1.0
 translate< 0,1.3,0>
} // end of isosurface -------------------------------------------------------