60001515 Excluding areas of triangles for GroundSurface object

Article 60001515
Type Wish
Product Engine
Version 6021
Date Added 10/18/2011
Fixed (10/18/2011)
Submitted by Alekos Ntermaris // Chandrshekhar // Massimo Endrighi

Summary

Excluding areas of triangles for GroundSurface object

Solution

New methods  VectorDraw.Geometry.Delaunay.Triangulate and GetSliceRegionPoints of gPoints was added in 6022

syntax:

public static gTriangles Triangulate(gPoints points, ushort precision)

Triangulates the given points using Delaunay algorithm.

points: Input sample points to triangulate

precision :The decimal precision for the passed points.

returns : A gTriangles collection.

gPoints GetSliceRegionPoints(vdArray<gPoints> SliceRegions, ushort precision)

Returns a collection of all points in SliceRegions, all intersection points between regions and all intersection between region segments and this Triangle collection.

SliceRegions : A collection of regions.

precision : The decimal precision for the passed points.

returns a collection of all points that belongs on SliceRegions projected on triangles of this collection.

Example of excluding regions from a triangulation


                //create an array of points that represent a mountain
                gPoints pts = new gPoints();
               
                //add points from a 16 segments divided circle with radius 10 and elevation 50
                pts += Globals.GetArcSamplePoints(16, 10, 0.0, Globals.VD_TWOPI, 50);
                //add points from a 32 segments divided circle with radius 20 and elevation 40
                pts += Globals.GetArcSamplePoints(32, 20, 0.0, Globals.VD_TWOPI,40);
                //add points from a 48 segments divided circle with radius 30 and elevation 30
                pts += Globals.GetArcSamplePoints(48, 30, 0.0, Globals.VD_TWOPI,30);
                //add points from a 64 segments divided circle with radius 40 and elevation 20
                pts += Globals.GetArcSamplePoints(64, 40, 0.0, Globals.VD_TWOPI,20);
                //add points from a 78 segments divided circle with radius 50 and elevation 10
                pts += Globals.GetArcSamplePoints(78, 50, 0.0, Globals.VD_TWOPI,10);
                //add a point at the top of the mountain.
                pts += new gPoint(0, 0, 60);


                //create an array of points that defines a region that will not contains triangles inside
                gPoints SliceRegionInside = new gPoints(new gPoint[] { new gPoint(-18, 3), new gPoint(-18, 18), new gPoint(-3, 18), new gPoint(-3, 3), new gPoint(-18, 3) });
                //create an array of points that defines a region that will not contains triangles outside it.
                gPoints SliceRegionOutside = new gPoints(new gPoint[] { new gPoint(-35, -35), new gPoint(-35, 35), new gPoint(35, 35), new gPoint(35, -35), new gPoint(-35, -35) });


                //add all the regions into a collection
                vdArray<gPoints> SliceRegions = new vdArray<gPoints>(new gPoints[] { SliceRegionInside, SliceRegionOutside });


                ushort percision = 8;
                //calculate the result triangles using decimal precision 8 for passed points.
                gTriangles newtriangles = Delaunay.Triangulate(pts, percision);
                //calculate all intersection points between SliceRegions and triangles.
                //Z values of intersections are projected on triangles collection.
                gPoints intPts = newtriangles.GetSliceRegionPoints(SliceRegions, percision);
                //re-calculate the triangles using the basic input points and the calculated intersections.
                newtriangles = Delaunay.Triangulate(pts + intPts, percision);
               
                //remove the triangles according to region usage.
                gTriangles RemovedInsideTriangles = newtriangles.RemoveInsideTriangles(SliceRegionInside);
                gTriangles RemovedOutsideTriangles = newtriangles.RemoveOutsideTriangles(SliceRegionOutside);


                //create a new ground sourface with the calculating triangles.
                vdGroundSurface gf = new vdGroundSurface();
                gf.SetUnRegisterDocument(doc);
                gf.setDocumentDefaults();
                gf.Points = pts;
                gf.SelectUserTriangles(newtriangles);
                gf.DispMode = vdGroundSurface.DisplayMode.Triangle;
                doc.Model.Entities.AddItem(gf);


                doc.CommandAction.Zoom("e", null, null);

Send comments on this topic.