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.)