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

  function{
             f_rounded_box(x,y,z,
                             0.2, // radius of curvature
                             1.0, 1.0, 1.0 // scale<x,y,z>
                          )
          }

  threshold 0
  contained_by {box {<-2,-2,-2>,<2,2,2>}}
  max_gradient 3.168
  accuracy 0.0001
  //evaluate 1,20,0.99

  texture { pigment{ color rgb<1,1,1>}
            //normal {bumps 0.5 scale 0.05}
            finish { phong 1}
	  }
  scale 0.80 
  rotate <0,-40,0>
  rotate <-30,0,0>  
  translate < 0, 1.2, 0>
} // end of isosurface -------------------------------------------------------