gull call.                            
  
                                          
 the seagull is  a metaphysics  trick;  a 
 world-builder's  shortcut, to  define  a 
 section of reality  and  imply its size: 
 place a  flock of birds at the edge  and 
 make  their  calls  tesselate  over  the 
 entire volume                            
                                          
 a  seagull can be  defined by as  little 
 as  five  vertices;  six  triangles.  (i 
 would recommend  handling in  swarms  of 
 at least a dozen birds.)