/// <summary>
/// Esporta una mesh poligonale in formato OFF.
/// </summary>
/// <param name="filename"></param>
/// <param name="mesh"></param>
/// <returns></returns>
public static bool SaveToOFF(string filename, DCELMesh mesh)
{
StreamWriter writer = File.CreateText(filename);
string v;
//header
writer.WriteLine("OFF");
//vertex and face count
writer.Write(mesh.VertexCount + " " + mesh.FaceCount + " " + mesh.HalfEdgeCount / 2);
writer.WriteLine();
//vertex list
foreach (var vertex in mesh.VertexList)
{
v = vertex.Coordinates.X + " " + vertex.Coordinates.Y + " " + vertex.Coordinates.Z;
writer.WriteLine(v.Replace(",", "."));
}
//face list
foreach (var face in mesh.FaceList)
{
writer.Write(face.Vertices().Count());
foreach (var vertex in face.Vertices())
{
writer.Write(" " + mesh.VertexList.IndexOf(vertex));
}
writer.WriteLine();
}
writer.Close();
return(true);
}
public static bool SerializeMesh(string filename, DCELMesh meshToSerialize)
{
Stream stream = File.Open(filename, FileMode.Create);
BinaryFormatter formatter = new BinaryFormatter();
formatter.Serialize(stream, meshToSerialize);
stream.Close();
return(true);
}
public DCELMesh(string filename)
{
DCELMesh mesh = DCELTools.LoadFromOFF(filename);
this.vertexList = mesh.VertexList;
this.vertexCount = mesh.VertexCount;
this.edgeList = mesh.HalfEdgeList;
this.edgeCount = mesh.HalfEdgeCount;
this.faceList = mesh.FaceList;
this.faceCount = mesh.FaceCount;
}
/// <summary>
///
/// </summary>
/// <param name="mesh"></param>
/// <returns></returns>
public static MeshGeometry3D GetMeshGeometry(DCELMesh mesh)
{
MeshGeometry3D mesh3d = new MeshGeometry3D();
Hashtable vIndexes = new Hashtable();
int n = 0;
mesh.Triangulate();
foreach (var point3d in mesh.VertexList)
{
mesh3d.Positions.Add(point3d.Coordinates);
mesh3d.Normals.Add(point3d.Normal);
vIndexes.Add(point3d, n++);
}
foreach (var face in mesh.FaceList)
{
DCELHalfEdge he = face.Edge;
DCELVertex first = he.Origin;
do
{
mesh3d.TriangleIndices.Add((int)vIndexes[he.Origin]);
he = he.Next;
}while (he.Origin != first);
}
/*
* foreach (var face in mesh.FaceList)
* {
* DCELHalfEdge he = face.Edge;
* DCELVertex first = he.Origin;
*
* do
* {
* mesh3d.Positions.Add(he.Origin.Coordinates);
* mesh3d.Normals.Add(he.Origin.Normal);
* mesh3d.TriangleIndices.Add(n++);
* he = he.Next;
* }
* while (he.Origin != first);
* }
*/
return(mesh3d);
}
/// <summary>
/// Carica una mesh poligonale da un Object File Format su una struttura DCEL.
/// </summary>
/// <param name="filename">Il percorso completo del file da caricare.</param>
/// <returns>Una mesh DCEL se caricata correttamente, null altrimenti.</returns>
public static DCELMesh LoadFromOFF(string filename)
{
Dictionary <int, List <int> > leavingEdges = new Dictionary <int, List <int> >();
Hashtable vIndexes = new Hashtable();
DCELMesh mesh = new DCELMesh();
StreamReader reader;
char[] separators = new char[] { ' ', '\t' };
int vertex_count = 0, face_count = 0;
try
{
reader = new StreamReader(filename);
}
catch (FileNotFoundException)
{
return(null);
}
string line = reader.ReadLine();
if (line == "OFF" || line == "NOFF")
{
while ((line = reader.ReadLine()) != null)
{
if (CheckLine(line))
{
string[] values = line.Split(separators, StringSplitOptions.RemoveEmptyEntries);
vertex_count = Convert.ToInt32(values[0]);
face_count = Convert.ToInt32(values[1]);
//MESH INITIALIZATION
#region Vertices Creation
//
for (int i = 0; i < vertex_count; i++)
{
line = reader.ReadLine();
if (CheckLine(line))
{
values = line.Split(separators, StringSplitOptions.RemoveEmptyEntries);
// x, y, z coordinates
mesh.AddVertex(new DCELVertex(new Point3D(
Double.Parse(values[0].Replace(',', '.')),
Double.Parse(values[1].Replace(',', '.')),
Double.Parse(values[2].Replace(',', '.'))), null));
leavingEdges.Add(i, new List <int>());
try
{
vIndexes.Add(mesh.VertexList[i], i);
}
catch (Exception)
{
//non possono esistere due vertici con le stesse coordinate
return(null);
}
}
else
{
i--;
}
}
//
#endregion
#region Faces Creation
//
int he_counter = 0;
for (int i = 0; i < face_count; i++)
{
line = reader.ReadLine();
if (CheckLine(line))
{
values = line.Split(separators, StringSplitOptions.RemoveEmptyEntries);
//k è il numero di vertici della faccia corrente
int k = Convert.ToInt32(values[0]);
int starting_index = he_counter;
bool check_first = true;
mesh.AddFace(new DCELFace());
//for each vertex
for (int j = 1; j <= k; j++)
{
//@vertex_index è l'indice del vertice all'interno della collezione VertexList
int vertex_index = Convert.ToInt32(values[j]);
#region Half Edges Calculation
if (check_first)
{
check_first = false;
//creo un nuovo halfedge e lo aggiungo alla lista
mesh.AddHalfEdge(new DCELHalfEdge());
//imposto come vertice di origine il point3d corrispondente all'indice vertex_index in VertexList
mesh.HalfEdgeList[he_counter].Origin = mesh.VertexList[vertex_index];
//imposto il primo halfedge come halfedge di riferimento della faccia corrente
mesh.FaceList[i].Edge = mesh.HalfEdgeList[he_counter];
//l'halfedge corrente si collega alla faccia corrente
mesh.HalfEdgeList[he_counter].Face = mesh.FaceList[i];
//
leavingEdges[vertex_index].Add(he_counter);
//incremento il contatore
he_counter += 1;
}
else
{
//creo un nuovo halfedge e lo aggiungo alla lista
mesh.AddHalfEdge(new DCELHalfEdge());
//l'halfedge successivo al precedente è quello corrente. Incremento face_count e assegno
mesh.HalfEdgeList[he_counter - 1].Next = mesh.HalfEdgeList[he_counter];
//assegno il punto d'origine corrispondente all'indice vertex_index in Mesh.VertexList
mesh.HalfEdgeList[he_counter].Origin = mesh.VertexList[vertex_index];
//collego l'halfedge alla faccia corrente
mesh.HalfEdgeList[he_counter].Face = mesh.FaceList[i];
//
leavingEdges[vertex_index].Add(he_counter);
//incremento il contatore
he_counter += 1;
}
//finito di iterare sui vertici, l'ultimo halfedge ha come next l'halfedge di partenza
mesh.HalfEdgeList[he_counter - 1].Next = mesh.HalfEdgeList[starting_index];
#endregion
}
//face normal
MathUtils.CalculateNormal(mesh.FaceList[i]);
}
else
{
i--;
}
}
//
#endregion
#region Leaving Edges and Vertex Normals Calculation
for (int i = 0; i < vertex_count; i++)
{
if (leavingEdges[i].Count > 0)
{
mesh.VertexList[i].Leaving = mesh.HalfEdgeList[leavingEdges[i][0]];
//face normal
mesh.VertexList[i].Normal = new Vector3D();
//for each leaving edge from the current vertex
foreach (var lEdgeIndex in leavingEdges[i])
{
//sum the face normals for every triangle containing the vertex
mesh.VertexList[i].Normal += mesh.HalfEdgeList[lEdgeIndex].Face.Normal;
}
//get average normal
mesh.VertexList[i].Normal /= leavingEdges[i].Count;
mesh.VertexList[i].Normal = MathUtils.Normalize(mesh.VertexList[i].Normal);
}
}
#endregion
#region Twin Edges Calculation
foreach (var edge in mesh.HalfEdgeList)
{
//index è la posizione in VertexList del vertice dell'edge successivo a quello corrente
int index = (int)vIndexes[edge.Next.Origin];
//edge_index è la posizione in EdgeList dell'edge con origine nel vertice dell'indice di cui sopra!
foreach (var edge_index in leavingEdges[index])
{
if (edge.Origin == mesh.HalfEdgeList[edge_index].Next.Origin)
{
edge.Twin = mesh.HalfEdgeList[edge_index];
break;
}
}
}
//
#endregion
reader.Close();
//restituisco la mesh caricata
return(mesh);
}
}
}
//if null is returned, something is gone wrong!
return(null);
}
