isosurface {  //------------------------------------------------
  
  function{ sqrt( x*x + y*y+ z*z) - 0.5 
            - f_noise3d( x*2, y*2, z*2 )*1.90
          }
  contained_by { box { -2.5, 2.5 } }
  accuracy 0.002
  max_gradient 5

  texture{ pigment{ color rgb<1,0.4,0.0>}
           finish { phong 1 reflection 0.1}}
  scale 0.55
  rotate<0,0,0> 
  translate <0,1.5,0> 
} // end of isosurface -----------------------------------------
