// #declare RADIUS = 0.75; /// ring
// #declare RADIUS = 1.00; /// horn
// #declare RADIUS = 1.60; /// spindle
#declare TORUS =
 difference {
  torus { RADIUS,1.001 }
  torus { RADIUS,1.000 }
  texture {
   uv_mapping
   pigment { checker rgb <0.8,0.95,1>, rgb <0.6,0.8,0.9> scale 0.08333 }
  }
  rotate <0,45,0>
 }
#declare CYLINDER =
 difference {
  cylinder { <0,0,0.2> <0,0,0.3> 1.01 }
  cylinder { <0,0,0.1> <0,0,0.4> 0.99 }
 }

intersection {
 object { TORUS }
 box { <-9,-9,-9> <9,0,9> }
 rotate <30,0,0> translate <0,1.3,0>
 finish { ambient rgb <1,1,1> specular 1 }
}
union {
 object { CYLINDER translate < RADIUS,0,0> }
 object { CYLINDER translate <-RADIUS,0,0> }
 translate <0,-1.5,0>
}

background   { color rgbt <1,1,1,0> }
light_source { <0,-1,1> color 0.3 parallel }
light_source { <0, 1,0> color 1   parallel }
light_source { <1, 2,8> color 1   parallel
 area_light <4,0,0>, <0,0,4>, 9, 9 adaptive 1 jitter }
camera {
 orthographic
 right    x * image_width / image_height
 location <0,0,8>
 look_at  <0,0,0>
 sky      <0,1,0>
 angle    37
}