isosurface { // ------------------------------------------------------------
  function{  
       y - cos(sqrt(x*x + z*z)*5*pi)*0.08
	  }
  threshold 0
  accuracy 0.0001
  max_gradient 5
  contained_by {box {<-1.5,-0.25,-1.5>, < 1.5, 1, 1.5>}}
  //open

  texture{ pigment{ color rgb<0.8,1,0.0>}
           finish { phong 1}
	  }
  scale 1.00
  rotate <-35, 25, 0>
  translate < 0, 1.4, 0>
} // end of isosurface -----------------------------------------------------