#version 3.7;
#include "colors.inc"
  camera {
    orthographic
    up <0, 6, 0>
    right <6, 0, 0>*image_width/image_height
    location <0.5, 2.5, -100>
    look_at <0.5, 2.5, 0>
  }
  
  /* set the control points to be used */
  #declare control_points = array[12]
    { <2,0>, <3,0>, <4,1>,
      <4,2>, <4,3>, <3,4>,
      <2,4>, <1, 4>, <0, 3>,
      <0,2>, <0, 1>, <1, 0>
    };
 
  /* color the control points in order */
  union {
  #for(I,0,11,1)
    cylinder { control_points[I] control_points[I]-<0,0,20> 0.08
      pigment { rgb <1-I/11, 0 I/11> }
      finish { emission 1 }
      }
  #end
  }
  
  
  /* something to make the curve show up */
  prism {
    linear_sweep
    bezier_spline
    1.0, //top
    0.0, // bottom
    16
    control_points[0], control_points[1], control_points[2], control_points[3],
    control_points[3], control_points[4], control_points[5], control_points[6],
    control_points[6], control_points[7], control_points[8], control_points[9],
    control_points[9], control_points[10], control_points[11], control_points[0]

    pigment { White }
    finish { emission 1 }
    rotate -90*x
  }