global_settings { assumed_gamma 1 }
default { pigment { rgb 0 } }
background { rgb 1 } 

#declare Length = 9;

#macro Dust(obj, Level)
   
   #declare new_obj = union {  

      object { obj scale <1/3,1,1> }
      object { obj scale <1/3,1,1> translate x*(Length*2/3) }

   }

   #if(Level!=1) Dust(new_obj,Level-1) 
   #else         object { new_obj }
   #end

#end

   //#include "sponge.inc"
   //#declare base_object =
   //mesh { Box(0,0,0,Length,0,Length) }
   
   #declare base_object = box { 0,<Length,0,Length> }
   
   #declare Recursion_Level=3;
   #debug concat(str(pow(2,Recursion_Level),1,0),"\n")
   
   object {
      Dust(base_object, Recursion_Level)
   }
   
   
   camera { location <Length*0.5,Length,Length*0.5> look_at <Length*0.5,0,Length*0.5> }
   light_source { <Length*0.5,Length*1.125,Length*0.5> rgb 1 }