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.Split(' ');
var pts = new Point3DCollection();
var tex = new PointCollection();
var norm = 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]) : -1;
int vni = ff.Length > 2 && ff[2].Length > 0 ? int.Parse(ff[2]) : -1;
pts.Add(Points[vi - 1]);
if (vti >= 0)
tex.Add(TexCoords[vti - 1]);
if (vni >= 0)
norm.Add(Normals[vni - 1]);
}
if (tex.Count == 0) tex = null;
if (norm.Count == 0) norm = null;
// QUAD
if (pts.Count == 4)
{
CurrentGroup.MeshBuilder.AddQuads(pts, norm, tex);
return;
}
// TRIANGLE
if (pts.Count == 3)
{
CurrentGroup.MeshBuilder.AddTriangles(pts, norm, tex);
return;
}
// 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
var mesh = new MeshBuilder();
mesh.Append(pts, tri);
CurrentGroup.MeshBuilder.Append(mesh);
}
}
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;
}
