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

  function{ sqrt(x*x + y*y + z*z) - 1
          }

  threshold 0
  contained_by {box {<-1,-1,-1>, < 1, 1, 1>}}
  open

  texture { pigment{ color rgb<1.0,0.7,0.3>}
            finish { specular 0.3 phong 1}
	  }
  scale 1
  rotate <-32, 25, 0>
  translate < 0, 1, 0>
} // end of isosurface -----------------------------------------------------