public static ModelVisual3D Representation3D(this XYPolygon Poly, IXYPoint refpoint, double height)
{
MeshBuilder mb = new MeshBuilder();
var pts = new Point3DCollection();
foreach (var p in Poly.Points)
{
pts.Add(new Point3D(refpoint.X - p.X, refpoint.Y - p.Y, height));
}
// POLYGONS (flat and convex)
var poly3D = new Polygon3D(pts);
// Transform the polygon to 2D
var poly2D = poly3D.Flatten();
// Triangulate
var tri = poly2D.Triangulate();
if (tri != null)
{
// Add the triangle indices with the 3D points
mb.Append(pts, tri);
}
var m = MaterialHelper.CreateMaterial(Colors.DimGray, 0.5);
var mv3D = new ModelVisual3D();
mv3D.Content = new GeometryModel3D(mb.ToMesh(), m);
return(mv3D);
}
public void Flatten_PlanarPolygon2_ReturnsCorrectResult()
{
var p = new Polygon3D();
p.Points.Add(new Point3D(0, 0, 4));
p.Points.Add(new Point3D(1, 0, 4));
p.Points.Add(new Point3D(1, 1, 4.01));
p.Points.Add(new Point3D(0, 1, 4.01));
var p2 = p.Flatten();
Assert.AreEqual(p2.Points.Count, 4);
var tri = p2.Triangulate();
Assert.AreEqual(6, tri.Count);
}
/// <summary>
/// The add face.
/// </summary>
/// <param name="values">
/// The values.
/// </param>
private void AddFace(string values)
{
// A polygonal face. The numbers are indexes into the arrays of vertex positions,
// texture coordinates, and normals respectively. A number may be omitted if,
// for example, texture coordinates are not being defined in the model.
// There is no maximum number of vertices that a single polygon may contain.
// The .obj file specification says that each face must be flat and convex.
var fields = values.SplitOnWhitespace();
var points = new Point3DCollection();
var textureCoordinates = new PointCollection();
var normals = new Vector3DCollection();
foreach (var field in fields)
{
if (string.IsNullOrEmpty(field))
{
continue;
}
var ff = field.Split('/');
int vi = int.Parse(ff[0]);
int vti = ff.Length > 1 && ff[1].Length > 0 ? int.Parse(ff[1]) : int.MaxValue;
int vni = ff.Length > 2 && ff[2].Length > 0 ? int.Parse(ff[2]) : int.MaxValue;
if (vi < 0)
{
vi = this.Points.Count + vi;
}
if (vti < 0)
{
vti = this.TexCoords.Count + vti;
}
if (vni < 0)
{
vni = this.Normals.Count + vni;
}
if (vi - 1 < this.Points.Count)
{
points.Add(this.Points[vi - 1]);
}
if (vti < int.MaxValue && vti - 1 < this.TexCoords.Count)
{
textureCoordinates.Add(this.TexCoords[vti - 1]);
}
if (vni < int.MaxValue && vni - 1 < this.Normals.Count)
{
normals.Add(this.Normals[vni - 1]);
}
}
if (textureCoordinates.Count == 0)
{
textureCoordinates = null;
}
if (normals.Count == 0)
{
normals = null;
}
if (normals == null)
{
// turn off normals in the mesh builder
//this.CurrentGroup.MeshBuilder.Normals = null;
}
if (textureCoordinates == null)
{
// turn off texture coordinates in the mesh builder
//this.CurrentGroup.MeshBuilder.TextureCoordinates = null;
}
// TRIANGLE
if (points.Count == 3)
{
this.CurrentGroup.MeshBuilder.AddTriangles(points, normals, textureCoordinates);
return;
}
// QUAD
if (points.Count == 4)
{
this.CurrentGroup.MeshBuilder.AddQuads(points, normals, textureCoordinates);
return;
}
// POLYGONS (flat and convex)
{
var poly3D = new Polygon3D(points);
// Transform the polygon to 2D
var poly2D = poly3D.Flatten();
// Triangulate
var triangleIndices = poly2D.Triangulate();
if (triangleIndices != null)
{
// Add the triangle indices with the 3D points
this.CurrentGroup.MeshBuilder.Append(points, triangleIndices, normals, textureCoordinates);
}
}
}