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.)