TriangleSubIndexArr ay (PolygonFace) *

Introduced

5.0

Description

Returns a 1-dimensional packed Array of triangulation descriptions corresponding to the tesselation of the polygon. The polygon is tesselated into (NbPoints - 2) triangles, and 3 indices in the range (0..NbPoints-1) are returned for each triangle. Each index triplet describes a subtriangle of the polygon, and the indices correspond to the vertex or node ordering within the polygon.

Notice that the triangulation of a polygon may change accordingly to the deformation of the geometry.

C# Syntax

    // get accessor
    Object rtn = PolygonFace.TriangleSubIndexArray;

Examples

JScript Example

    /*
       This example demonstrates how to describe the triangulation of some polygons.
    */

    NewScene( null, false );
    var SphereGeom = Application.ActiveSceneRoot.AddGeometry("Sphere", "MeshSurface").ActivePrimitive.Geometry;
    var Polygons = SphereGeom.Polygons;

    for(i = 0; i < Polygons.Count; i++)
    {
       var Polygon = Polygons.Item(i);
       var NbTriangles = Polygon.NbPoints-2;

       var PolygonVertices = Polygon.Vertices;
       var PolygonNodes = Polygon.Nodes;
       var TriangleSubIndices = Polygon.TriangleSubIndexArray.toArray();

       for(j = 0; j < NbTriangles; j++)
       {
           Application.LogMessage("SubTriangle " + j + " of Polygon " + i + " correspond to vertices (" +
              PolygonVertices.Item(TriangleSubIndices[j*3]).Index + ", " +
              PolygonVertices.Item(TriangleSubIndices[j*3+1]).Index + ", " +
              PolygonVertices.Item(TriangleSubIndices[j*3+2]).Index + ") and nodes (" +
              PolygonNodes.Item(TriangleSubIndices[j*3]).Index + ", " +
              PolygonNodes.Item(TriangleSubIndices[j*3+1]).Index + ", " +
              PolygonNodes.Item(TriangleSubIndices[j*3+2]).Index + ").");
       }
    }

    // Expected results:
    //INFO : SubTriangle 0 of Polygon 0 correspond to vertices (9, 2, 0) and nodes (0, 1, 2).
    //INFO : SubTriangle 0 of Polygon 1 correspond to vertices (2, 9, 10) and nodes (3, 4, 5).
    //INFO : SubTriangle 1 of Polygon 1 correspond to vertices (2, 10, 3) and nodes (3, 5, 6).
    //INFO : SubTriangle 0 of Polygon 2 correspond to vertices (3, 10, 11) and nodes (7, 8, 9).
    //INFO : SubTriangle 1 of Polygon 2 correspond to vertices (3, 11, 4) and nodes (7, 9, 10).
    //etc.

See Also

PolygonFace.Vertices | PolygonFace.Nodes

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