// FUNCTION - FUNCTIONS by ISOSURFACE / An Eddy '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 <-3, -10, -12>
  look_at <0, 0, 0>
  angle 18
  }

light_source {<0, 0, 0> color rgb <0, 0, 1>}
light_source {<0, -10, -10> color rgb <0.5, 1, 0.7>}

isosurface {
  function {y+3.6/(x*x+z*z+1)+0.1*sqrt(x*x+z*z)*cos(2*atan(z/x)
            -30*pi/(x*x+z*z+1))}
  threshold 0
  max_gradient 3
  contained_by {box {<-7, -5, -7>, <7, 4, 10>}}
  open
  texture {
    pigment {color rgbt <0.3, 0.4, 0.6, 0.2>}
    finish {
      ambient 0
      diffuse 1
      reflection 0.2
      phong 1
      phong_size 20
      specular 1
      roughness 0.1
      brilliance 0.5
      }
    }
  scale 1/vlength(1)
  no_shadow
  }