Generating Realistic Terrains with Higher-Order Delaunay Triangulations

For hydrologic applications, terrain models should have few local minima, and drainage lines should coincide with edges. We show that triangulating a set of points with elevations such that the number of local minima of the resulting terrain is minimized is NP-hard for degenerate point sets. The same result applies when there are no degeneracies for higher-order Delaunay triangulations. Two heuristics are presented to reduce the number of local minima for higher-order Delaunay triangulations, which start out with the Delaunay triangulation. We give efficient algorithms for their implementation, and test on real-world data how well they perform. We also study another desirable drainage characteristic, few valley components, and how to obtain it for higher-order Delaunay triangulations. This gives rise to a third heuristic. Tables and visualizations show how the heuristics perform for the drainage characteristics on real-world data.


slides

Journal Article

Thierry de Kok, Marc van Kreveld, Maarten Löffler
Generating Realistic Terrains with Higher-Order Delaunay Triangulations
Computational Geometry: Theory and Applications
36(1), 52–65, 2007
http://dx.doi.org/10.1016/j.comgeo.2005.09.005

Technical Report

Thierry de Kok, Marc van Kreveld, Maarten Löffler
Generating Realistic Terrains with Higher-Order Delaunay Triangulations
Utrecht University, Department of Information and Computing Sciences
UU-CS-2005-020, 2005
http://www.cs.uu.nl/research/techreps/UU-CS-2005-020.html

Conference Proceedings

Thierry de Kok, Marc van Kreveld, Maarten Löffler
Generating Realistic Terrains with Higher-Order Delaunay Triangulations
Proc. 13th European Symposium on Algorithms
LNCS 3669, 343–354, 2005
http://dx.doi.org/10.1007/11561071_32

Conference Proceedings (non-competitive)

Thierry de Kok, Marc van Kreveld, Maarten Löffler
Minimizing Local Minima in Terrains with Higher-Order Delaunay Triangulations
Proc. 21st European Workshop on Computational Geometry
115–118, 2005
Invited to Special Issue of CGTA

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