#version 3.5
light_source { <10, 10, 50> rgb 1 }
camera { orthographic location <0,0,4> look_at  <0,0,0>  right 2.1*x up 2.1*y  }
prism {
  conic_sweep
  linear_spline
  1,  0.5,   4, <-1, -1>,< 1, -1>,<1, 1>,<-1,  1>
  rotate  -(88+frame_number)*x
  pigment { color rgb 1  }
  finish { ambient 0 diffuse 1}
}