I need to describe 2D objects using what Samet calls the boundary

model (He describes this for modeling 3D solids). It seems to me that I can

use analagous model for 2D using edges, vertices, polygons and no faces. I am

starting to work on this subject and I would appreciate if some one can give

some pointers to algorithms/code/references/data-structures that I could use

to understand how it works.

Thanks in advance.

ulisses.

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