elementary partitions of line segments in the plane

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Mathieu Brévilliers, Laboratoire MIA, UHA Elementary Partitions of Line Segments in the Plane

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Elementary Partitions of Line Segments in the Plane. Point set triangulations. Point set triangulations. Delaunay triangulations. Duality. Legal edge property. Legal edge property. The Delaunay triangulation is the unique triangulation without illegal edge. - PowerPoint PPT Presentation

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Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary Partitions of Line Segments in the

Plane

Mathieu Brévilliers, Laboratoire MIA, UHA

Point set triangulations

Mathieu Brévilliers, Laboratoire MIA, UHA

Point set triangulations

Mathieu Brévilliers, Laboratoire MIA, UHA

Delaunay triangulations

Mathieu Brévilliers, Laboratoire MIA, UHA

Duality

Mathieu Brévilliers, Laboratoire MIA, UHA

Legal edge property

Mathieu Brévilliers, Laboratoire MIA, UHA

Legal edge property

The Delaunay triangulation is the unique triangulation without illegal edge.

O(n) checker for Delaunay triangulations

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary partitions

Mathieu Brévilliers, Laboratoire MIA, UHA

Shape of edges

Mathieu Brévilliers, Laboratoire MIA, UHA

Shape of edges

Mathieu Brévilliers, Laboratoire MIA, UHA

Shape of edges

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Topology

Mathieu Brévilliers, Laboratoire MIA, UHA

Numbers of edges and faces

3n – n’ – 3 edges

2n – n’ – 2 faces

n : number of sites n’ : number of sides of the CH that are not sites

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary Delaunay partition

Mathieu Brévilliers, Laboratoire MIA, UHA

Elementary Delaunay partition

Mathieu Brévilliers, Laboratoire MIA, UHA

Duality

Mathieu Brévilliers, Laboratoire MIA, UHA

Legal edge property

Mathieu Brévilliers, Laboratoire MIA, UHA

Legal edge property

Legal Illegal

Mathieu Brévilliers, Laboratoire MIA, UHA

Legal edge property

The elementary Delaunay partition is the unique elementary partition without illegal edge.

Mathieu Brévilliers, Laboratoire MIA, UHA

Checker for Delaunay topologyTopology Geometry with faces in

Delaunay positions

Is it an elementary partition ?

Mathieu Brévilliers, Laboratoire MIA, UHA

Checker for Delaunay topology

a

b c

d

a

bc

d

Mathieu Brévilliers, Laboratoire MIA, UHA

Checker for Delaunay topology

1. For each edge, the test runs in constant time

2. O(n) edges in an elementary partition

Linear algorithm

Mathieu Brévilliers, Laboratoire MIA, UHA

Future works

Flip algorithm

Equiangularity for elementary Delaunay partitions

More general set of sites

Higher dimensions

Mathieu Brévilliers, Laboratoire MIA, UHA

Thank you!