public static IGeometry GetExample5() { const double CylinderBaseDegrees = 360.0; const int CylinderBaseDivisions = 8; const double VectorComponentOffset = 0.0000001; const double CylinderBaseRadius = 3; const double CylinderUpperZ = 8; const double CylinderLowerZ = 0; //Vector3D: Cylinder, TriangleStrip With 8 Vertices IGeometryCollection multiPatchGeometryCollection = new MultiPatchClass(); IPointCollection triangleStripPointCollection = new TriangleStripClass(); //Set Cylinder Base Origin To (0, 0, 0) IPoint originPoint = GeometryUtilities.ConstructPoint3D(0, 0, 0); //Define Upper Portion Of Axis Around Which Vector Should Be Rotated To Generate Cylinder Base Vertices IVector3D upperAxisVector3D = GeometryUtilities.ConstructVector3D(0, 0, 10); //Define Lower Portion of Axis Around Which Vector Should Be Rotated To Generate Cylinder Base Vertices IVector3D lowerAxisVector3D = GeometryUtilities.ConstructVector3D(0, 0, -10); //Add A Slight Offset To X or Y Component Of One Of Axis Vectors So Cross Product Does Not Return A Zero-Length Vector lowerAxisVector3D.XComponent += VectorComponentOffset; //Obtain Cross Product Of Upper And Lower Axis Vectors To Obtain Normal Vector To Axis Of Rotation To Generate Cylinder Base Vertices IVector3D normalVector3D = upperAxisVector3D.CrossProduct(lowerAxisVector3D) as IVector3D; //Set Normal Vector Magnitude Equal To Radius Of Cylinder Base normalVector3D.Magnitude = CylinderBaseRadius; //Obtain Angle Of Rotation In Radians As Function Of Number Of Divisions Within 360 Degree Sweep Of Cylinder Base double rotationAngleInRadians = GeometryUtilities.GetRadians(CylinderBaseDegrees / CylinderBaseDivisions); for (int i = 0; i < CylinderBaseDivisions; i++) { //Rotate Normal Vector Specified Rotation Angle In Radians Around Either Upper Or Lower Axis normalVector3D.Rotate(rotationAngleInRadians, upperAxisVector3D); //Construct Cylinder Base Vertex Whose XY Coordinates Are The Sum Of Origin XY Coordinates And Normal Vector XY Components IPoint vertexPoint = GeometryUtilities.ConstructPoint3D(originPoint.X + normalVector3D.XComponent, originPoint.Y + normalVector3D.YComponent, 0); //Construct Lower Base Vertex From This Point And Add To TriangleStrip IPoint lowerVertexPoint = GeometryUtilities.ConstructPoint3D(vertexPoint.X, vertexPoint.Y, CylinderLowerZ); triangleStripPointCollection.AddPoint(lowerVertexPoint, ref _missing, ref _missing); //Construct Upper Base Vertex From This Point And Add To TriangleStrip IPoint upperVertexPoint = GeometryUtilities.ConstructPoint3D(vertexPoint.X, vertexPoint.Y, CylinderUpperZ); triangleStripPointCollection.AddPoint(upperVertexPoint, ref _missing, ref _missing); } //Re-Add The First And Second Points Of The Triangle Strip (First Two Vertices Added) To Close The Strip triangleStripPointCollection.AddPoint(triangleStripPointCollection.get_Point(0), ref _missing, ref _missing); triangleStripPointCollection.AddPoint(triangleStripPointCollection.get_Point(1), ref _missing, ref _missing); //Add TriangleStrip To MultiPatch multiPatchGeometryCollection.AddGeometry(triangleStripPointCollection as IGeometry, ref _missing, ref _missing); return(multiPatchGeometryCollection as IGeometry); }
public static IGeometry GetExample5() { const double CylinderBaseDegrees = 360.0; const int CylinderBaseDivisions = 8; const double VectorComponentOffset = 0.0000001; const double CylinderBaseRadius = 3; const double CylinderUpperZ = 8; const double CylinderLowerZ = 0; //Vector3D: Cylinder, TriangleStrip With 8 Vertices IGeometryCollection multiPatchGeometryCollection = new MultiPatchClass(); IPointCollection triangleStripPointCollection = new TriangleStripClass(); //Set Cylinder Base Origin To (0, 0, 0) IPoint originPoint = GeometryUtilities.ConstructPoint3D(0, 0, 0); //Define Upper Portion Of Axis Around Which Vector Should Be Rotated To Generate Cylinder Base Vertices IVector3D upperAxisVector3D = GeometryUtilities.ConstructVector3D(0, 0, 10); //Define Lower Portion of Axis Around Which Vector Should Be Rotated To Generate Cylinder Base Vertices IVector3D lowerAxisVector3D = GeometryUtilities.ConstructVector3D(0, 0, -10); //Add A Slight Offset To X or Y Component Of One Of Axis Vectors So Cross Product Does Not Return A Zero-Length Vector lowerAxisVector3D.XComponent += VectorComponentOffset; //Obtain Cross Product Of Upper And Lower Axis Vectors To Obtain Normal Vector To Axis Of Rotation To Generate Cylinder Base Vertices IVector3D normalVector3D = upperAxisVector3D.CrossProduct(lowerAxisVector3D) as IVector3D; //Set Normal Vector Magnitude Equal To Radius Of Cylinder Base normalVector3D.Magnitude = CylinderBaseRadius; //Obtain Angle Of Rotation In Radians As Function Of Number Of Divisions Within 360 Degree Sweep Of Cylinder Base double rotationAngleInRadians = GeometryUtilities.GetRadians(CylinderBaseDegrees / CylinderBaseDivisions); for (int i = 0; i < CylinderBaseDivisions; i++) { //Rotate Normal Vector Specified Rotation Angle In Radians Around Either Upper Or Lower Axis normalVector3D.Rotate(rotationAngleInRadians, upperAxisVector3D); //Construct Cylinder Base Vertex Whose XY Coordinates Are The Sum Of Origin XY Coordinates And Normal Vector XY Components IPoint vertexPoint = GeometryUtilities.ConstructPoint3D(originPoint.X + normalVector3D.XComponent, originPoint.Y + normalVector3D.YComponent, 0); //Construct Lower Base Vertex From This Point And Add To TriangleStrip IPoint lowerVertexPoint = GeometryUtilities.ConstructPoint3D(vertexPoint.X, vertexPoint.Y, CylinderLowerZ); triangleStripPointCollection.AddPoint(lowerVertexPoint, ref _missing, ref _missing); //Construct Upper Base Vertex From This Point And Add To TriangleStrip IPoint upperVertexPoint = GeometryUtilities.ConstructPoint3D(vertexPoint.X, vertexPoint.Y, CylinderUpperZ); triangleStripPointCollection.AddPoint(upperVertexPoint, ref _missing, ref _missing); } //Re-Add The First And Second Points Of The Triangle Strip (First Two Vertices Added) To Close The Strip triangleStripPointCollection.AddPoint(triangleStripPointCollection.get_Point(0), ref _missing, ref _missing); triangleStripPointCollection.AddPoint(triangleStripPointCollection.get_Point(1), ref _missing, ref _missing); //Add TriangleStrip To MultiPatch multiPatchGeometryCollection.AddGeometry(triangleStripPointCollection as IGeometry, ref _missing, ref _missing); return multiPatchGeometryCollection as IGeometry; }