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

  function { x }
  contained_by { box { -2, 2 } }
  accuracy 0.003
  max_gradient 5

  texture{ pigment{ color rgb<1,0.7,0.15>}
           finish { specular 0.2 phong 1}}
  scale 0.5
  rotate<0,20,0>
  translate <0, 1, 0>
} // end of isosurface -----------------------------------------------------