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
keywords: Computational Geometry, Delaunay Triangulations, Geographical Information Analysis, Terrains

Journal Article (peer-reviewed)

Maarten Löffler, Marc van Kreveld, Thierry de Kok
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

Conference Proceedings (peer-reviewed)

Maarten Löffler, Marc van Kreveld, Thierry de Kok
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

Workshop or Poster (weakly reviewed)

Maarten Löffler, Marc van Kreveld, Thierry de Kok
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

Technical Report (not reviewed)

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

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