// Add a regular polygon with optional texture coordinates.
public static void AddRegularPolygon(this MeshGeometry3D mesh,
int numSides, Point3D center, Vector3D vx, Vector3D vy,
Point[] textureCoords = null)
{
// Generate the points.
Point3D[] points = G3.MakePolygonPoints(numSides, center, vx, vy);
// Make the polygon.
mesh.AddPolygon(points, textureCoords);
}
// Define the model.
private void DefineModel(Model3DGroup group)
{
// Define a polygon in the XZ plane.
Point3D center = new Point3D(0, 0, 4.5);
Point3D[] polygon = G3.MakePolygonPoints(6, center,
new Vector3D(1, 0, 0), new Vector3D(0, 0, -1));
// Make a transform to move the polygon in the -Z direction.
TranslateTransform3D translate = new TranslateTransform3D(0, 0, -3);
// Make a right pyramid.
MeshGeometry3D mesh1 = new MeshGeometry3D();
mesh1.AddPyramid(center, polygon, new Vector3D(0, 3, 0));
group.Children.Add(mesh1.MakeModel(Brushes.Pink));
// Make a skewed pyramid.
translate.Transform(polygon);
center = translate.Transform(center);
MeshGeometry3D mesh2 = new MeshGeometry3D();
mesh2.AddPyramid(center, polygon, new Vector3D(0, 3, 2));
group.Children.Add(mesh2.MakeModel(Brushes.LightBlue));
// Make a frustum with cutting plane parallel to the base.
translate.Transform(polygon);
center = translate.Transform(center);
MeshGeometry3D mesh3 = new MeshGeometry3D();
mesh3.AddFrustum(center, polygon, new Vector3D(0, 4, 0), 2);
group.Children.Add(mesh3.MakeModel(Brushes.LightGreen));
// Make a frustum with cutting plane not parallel to the base.
translate.Transform(polygon);
center = translate.Transform(center);
MeshGeometry3D mesh4 = new MeshGeometry3D();
Point3D planePt = center + new Vector3D(0, 2, 0);
Vector3D planeN = new Vector3D(1, 1, 1);
mesh4.AddFrustum(center, polygon, new Vector3D(0, 4, 0), planePt, planeN);
group.Children.Add(mesh4.MakeModel(Brushes.Orange));
// Show the axes.
MeshExtensions.AddAxes(group);
}