Authors:
Jan Mikula
1
;
2
and
Miroslav Kulich
1
Affiliations:
1
Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslávských partyzánů 1580/3, 16000 Praha 6, Czech Republic
;
2
Department of Cybernetics, Faculty of Electrical Engineering, Czech Technical University in Prague, Karlovo náměstí 13, 12135 Praha 2, Czech Republic
Keyword(s):
Autonomous Agents, Visibility Region, Triangular Expansion Algorithm, Triangulation, TriVis.
Abstract:
Visibility region is a classic structure in computational geometry that finds use in many agent planning prob-lems. Triangular expansion algorithm (TEA) is the state-of-the-art algorithm for computing visibility regions within polygons with holes in two dimensions. It has been shown that it is two orders of magnitude faster than the traditional rotation sweep algorithm for real-world scenarios. The algorithm triangulates the underlying polygon and recursively traverses the triangulation while keeping track of the visible region. Instead of the constraint Delaunay triangulation used by default, this paper introduces the idea of optimizing the triangulation to minimize the expected number of triangle edges expanded during the TEA’s traversal while assuming that every point of the input polygon is equally likely to be queried. The proposed triangulation is experimentally evaluated and shown to improve TEA’s mean query time in practice. Furthermore, the TEA is modified to consider limite
d visibility range of real-life sensors. Combined with the proposed triangulation, this adjustment significantly speeds up the computation in scenarios with limited visibility. We provide an efficient open-source implementation called TriVis which, besides the mentioned, includes determining visibility between two points and other useful visibility-related operations.
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