// TWIST / A Cup '02.10
// By Tsutomu HIGO  E-mail: nj2t-hg@asahi-net.or.jp

#version 3.5;
global_settings {
  max_trace_level 5
  assumed_gamma 2.2
  }

#include "functions.inc"

isosurface {
  function {
    ((cos(y)*x-sin(y)*z)*(cos(y)*x-sin(y)*z)+y*y/2+(sin(y)*x+cos(y)*z)*(sin(y)*x+cos(y)*z)-25)
    *((cos(y)*x-sin(y)*z)*(cos(y)*x-sin(y)*z)*1.2+(y-0.2)*(y-0.2)/2+(sin(y)*x+cos(y)*z)*(sin(y)*x+cos(y)*z)-22)
    +4
    }
  threshold 0
  contained_by { sphere {<0, 0, 0> 7 } }
  max_gradient 600
  texture {
    pigment { color rgbt <1, 1, 1, 0.4> }
    finish {
      ambient 0.5
      reflection 0.5
      diffuse 0.3
      phong 0.3
      specular 1
      brilliance 1.5
      }
    }
  rotate y*120 rotate x*60 rotate y*120
  no_shadow
  }

camera {
  location <0, 20, -50>
  angle 15
  look_at <0, 0.1, 0>
  }

light_source { <-500, 1500, -1000> color rgb <0.3, 0.5, 1> }