isosurface { //-------------------------------------------------------------
  function{  
    y - sin(x*4*pi)*0.1
  }
  threshold 0
  contained_by {box {<-1,-0.5,-1>, < 1, 1, 1>}}
  //open

  texture{ pigment{ color rgb<1,0.6,0.0>}
           finish { phong 1}
	 }
  scale 1.5
  rotate <-35, 25, 0>
  translate < 0.1, 1.7, 0>
} // end of isosurface -----------------------------------------------------