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

  function { f_heart( x,y,z,  -0.15 )
           }

  threshold 0.0
  accuracy 0.0001
  max_gradient 100
  contained_by {box {<-1.1,-1.5,-1.1>,< 1.1,1.22,1.5>}}
  //open
  texture { pigment{ color rgb<1,0.7,0.1>}
            //normal {bumps 0.5 scale 0.05}
            finish { phong 1 specular 0.3 }
	  }
  scale 1.00
  rotate <-90, 90, 0>
  translate <-0, 1.1, 0>
} // end of isosurface -------------------------------------------------------