global_settings { radiosity {} }

#macro S(X, Z, I, R)
  sor
  { 6
    <5, 0> <8, 1> <12, 20> <5, 30> <6, 31> <7, 32>
    open
    translate <X, -40 Z>
  }

  // Call S() recursively if I > 0:
  #if(I)
    S(rand(R)*400-200 X, I-1 R)
  #end
#end

union
{ S(0, 0, 60 seed(7))
  plane { y, -40 }
  pigment { rgb <1, .6> }
  normal { bumps .1 }
  rotate -20*x
}

light_source { x*99, 2 }