Fig. 14 
  
  
Fig. 11 Querying all susfaces 
neighbouring the the Surface A 
  
Fig. 12 Querying all surfaces 
relating to the Line A 
[——-—- 
  
emma da eines 
   
| "a 
| 
Fig. 13 The result of an intersection 
set operation 
  
Converting vector into linear quadtree 
772 
nr i3 
A 
Come 
E 
AN 
Fig. 15 A vector map from linear quadtree. 
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