Table of Contents

Class SeidelDecomposer

Namespace
Alis.Core.Physic.Common.Decomposition
Assembly
Alis.dll

Convex decomposition algorithm created by Raimund Seidel Properties:

  • Decompose the polygon into trapezoids, then triangulate.
  • To use the trapezoid data, use ConvexPartitionTrapezoid()
  • Generate a lot of garbage due to incapsulation of the Poly2Tri library.
  • Running time is O(n log n), n = number of vertices.
  • Running time is almost linear for most simple polygons.
  • Does not care about winding order. For more information, see Raimund Seidel's paper "A simple and fast incremental randomized algorithm for computing trapezoidal decompositions and for triangulating polygons" See also: "Computational Geometry", 3rd edition, by Mark de Berg et al, Chapter 6.2 "Computational Geometry in C", 2nd edition, by Joseph O'Rourke Original code from the Poly2Tri project by Mason Green. http://code.google.com/p/poly2tri/source/browse?repo=archive#hg/scala/src/org/poly2tri/seidel This implementation is from Dec 14, 2010
internal static class SeidelDecomposer

Inheritance

Inherited Members

Methods

ConvexPartition(Vertices, float)

Decompose the polygon into several smaller non-concave polygons.

public static List<Vertices> ConvexPartition(Vertices vertices, float sheer = 0.001)

Parameters

vertices Vertices

The polygon to decompose.

sheer float

The sheer to use if you get bad results, try using a higher value.

Returns

List<Vertices>

A list of triangles

ConvexPartitionTrapezoid(Vertices, float)

Decompose the polygon into several smaller non-concave polygons.

public static List<Vertices> ConvexPartitionTrapezoid(Vertices vertices, float sheer = 0.001)

Parameters

vertices Vertices

The polygon to decompose.

sheer float

The sheer to use if you get bad results, try using a higher value.

Returns

List<Vertices>

A list of trapezoids