// FUNCTION - FUNCTIONS by ISOSURFACE / Watchers '02.07
// By Tsutomu HIGO  E-mail: nj2t-hg@asahi-net.or.jp

#version 3.5;
global_settings {
  max_trace_level 6
  assumed_gamma 2.2
  }

camera {
  location <0, 1, -8>
  look_at <0, 4, 0>
  angle 140
  }

light_source {<10, 0, -30> color rgb <0.3, 0.7, 1>}
light_source {<-20, 150, -75> color rgb <1, 1, 1>}

isosurface {
  function {y*y*x+sin(z*pi/3)*sin(x*pi/3)*5+x*x+1}
  threshold 0
  max_gradient 30
  contained_by {box {<-10, -10, -25>, <5, 20, 50>}}
  open
  texture {
    pigment {color rgb <0.5, 0.5, 0.5>}
    finish {
      ambient 0.3
      diffuse 1
      specular 1
      roughness 0.02
      brilliance 2
      }
    }
  scale 2/vlength(1)
  rotate <30, 64, 0>
  translate x*10
  }

background {color rgb <0.5, 0.7, 1>}