isosurface { //--------------------------------------------
  function{ 
     
    f_noise3d( x*2, y*2, z*2)-0.25  
  
  }
  contained_by { box { <-1,-0.75,-1>*2.5,<1,1,1>*2.5 } }
  accuracy 0.002
  max_gradient 4

  texture{ pigment{ color rgb<1,0.6,0.1>}
           finish { phong 1 reflection 0.2}}
  scale 0.5
  rotate<0,30,0>
  translate <0,1.2,0> 
} // end of isosurface  -----------------------------------