public void ComputeNormal(QuadMesh quadMesh)
{
foreach (QuadMesh.Face face in quadMesh.Faces)
{
QuadMesh.Vertex v0 = face.GetVertex(0);
QuadMesh.Vertex v1 = face.GetVertex(1);
QuadMesh.Vertex v2 = face.GetVertex(2);
QuadMesh.Vertex v3 = face.GetVertex(3);
Vector3D normal1 = (v2.Traits.Position - v1.Traits.Position).Cross(v0.Traits.Position - v2.Traits.Position);
normal1.Normalize();
Vector3D normal2 = (v0.Traits.Position - v3.Traits.Position).Cross(v2.Traits.Position - v0.Traits.Position);
normal2.Normalize();
face.Traits.Normal = (normal1 + normal2) / 2;
}
foreach (QuadMesh.Vertex vertex in quadMesh.Vertices)
{
vertex.Traits.Normal = Vector3D.Zero;
foreach (QuadMesh.Face face in vertex.Faces)
{
vertex.Traits.Normal += face.Traits.Normal;
}
vertex.Traits.Normal /= vertex.FaceCount;
}
}
public QuadMesh CreatePlane(int column, int row)
{
QuadMesh shape = new QuadMesh();
for (int i = 0; i < row; i++)
{
for (int j = 0; j < column; j++)
{
shape.Vertices.Add(new VertexTraits((double)i / (double)row, (double)j / (double)column, 0));
}
}
QuadMesh.Vertex[] faceVertices = new QuadMesh.Vertex[4];
for (int i = 0; i < row - 1; i++)
{
for (int j = 0; j < column - 1; j++)
{
faceVertices[0] = shape.Vertices[i * column + j];
faceVertices[1] = shape.Vertices[i * column + j + 1];
faceVertices[2] = shape.Vertices[(i + 1) * column + j + 1];
faceVertices[3] = shape.Vertices[(i + 1) * column + j];
shape.Faces.AddQuads(faceVertices);
}
}
return(shape);
}
private void ChangeGeometryCatMullClark(QuadMesh sourceMesh, QuadMesh targetMesh)
{
for (int i = 0; i < sourceMesh.Vertices.Count; i++)
{
Vector3D position = new Vector3D(0, 0, 0);
if (sourceMesh.Vertices[i].OnBoundary)
{
int n = 0;
foreach (QuadMesh.Vertex neighbor in sourceMesh.Vertices[i].Vertices)
{
if (neighbor.OnBoundary)
{
position += neighbor.Traits.Position;
n++;
}
}
targetMesh.Vertices[i].Traits.Position =
sourceMesh.Vertices[i].Traits.Position * 3 / 4
+ position * 1 / (4 * n);
}
else
{
foreach (QuadMesh.Vertex neighbor in sourceMesh.Vertices[i].Vertices)
{
position += neighbor.Traits.Position;
}
int n = Mesh.Vertices[i].VertexCount;
double beta = LoopComputeBeta(n);
targetMesh.Vertices[i].Traits.Position =
(1 - n * beta) *
Mesh.Vertices[i].Traits.Position +
beta * position;
}
}
//update new added vertex position
for (int i = 0; i < sourceMesh.Edges.Count; i++)
{
Vector3D position = new Vector3D(0, 0, 0);
QuadMesh.Vertex vertex0 = sourceMesh.Edges[i].Vertex0;
QuadMesh.Vertex vertex1 = sourceMesh.Edges[i].Vertex1;
if (sourceMesh.Edges[i].OnBoundary)
{
position = (vertex0.Traits.Position + vertex1.Traits.Position) / 2;
}
else
{
QuadMesh.Vertex vertex2 = sourceMesh.Edges[i].HalfEdge0.Next.ToVertex;
QuadMesh.Vertex vertex3 = sourceMesh.Edges[i].HalfEdge1.Next.ToVertex;
position = (vertex0.Traits.Position + vertex1.Traits.Position) * 3 / 8 +
(vertex2.Traits.Position + vertex3.Traits.Position) * 1 / 8;
}
targetMesh.Vertices[sourceMesh.Vertices.Count + i].Traits.Position = position;
}
}
public QuadMesh CreateCube()
{
QuadMesh shape = new QuadMesh();
shape.Vertices.Add(new VertexTraits(0, 0, 0));
shape.Vertices.Add(new VertexTraits(0, 0.5, 0));
shape.Vertices.Add(new VertexTraits(0.5, 0.5, 0));
shape.Vertices.Add(new VertexTraits(0.5, 0, 0));
shape.Vertices.Add(new VertexTraits(0, 0, 0.5));
shape.Vertices.Add(new VertexTraits(0, 0.5, 0.5));
shape.Vertices.Add(new VertexTraits(0.5, 0.5, 0.5));
shape.Vertices.Add(new VertexTraits(0.5, 0, 0.5));
QuadMesh.Vertex[] faceVertices = new QuadMesh.Vertex[4];
faceVertices[0] = shape.Vertices[0];
faceVertices[1] = shape.Vertices[1];
faceVertices[2] = shape.Vertices[2];
faceVertices[3] = shape.Vertices[3];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[5];
faceVertices[1] = shape.Vertices[4];
faceVertices[2] = shape.Vertices[7];
faceVertices[3] = shape.Vertices[6];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[1];
faceVertices[1] = shape.Vertices[0];
faceVertices[2] = shape.Vertices[4];
faceVertices[3] = shape.Vertices[5];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[2];
faceVertices[1] = shape.Vertices[1];
faceVertices[2] = shape.Vertices[5];
faceVertices[3] = shape.Vertices[6];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[3];
faceVertices[1] = shape.Vertices[2];
faceVertices[2] = shape.Vertices[6];
faceVertices[3] = shape.Vertices[7];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[0];
faceVertices[1] = shape.Vertices[3];
faceVertices[2] = shape.Vertices[7];
faceVertices[3] = shape.Vertices[4];
shape.Faces.AddQuads(faceVertices);
//shape.Vertices.Add(new VertexTraits(0.25, 0.25, 0));
//shape.Vertices.Add(new VertexTraits(0, 0.25, 0));
//shape.Vertices.Add(new VertexTraits(0.25, 0, 0));
//faceVertices[0] = shape.Vertices[0];
//faceVertices[1] = shape.Vertices[3];
//faceVertices[2] = shape.Vertices[7];
//faceVertices[3] = shape.Vertices[4];
//shape.Faces.AddQuads(faceVertices);
//ChangTopolopy(shape);
return(shape);
}
public QuadMesh CreateCube()
{
QuadMesh shape = new QuadMesh();
shape.Vertices.Add(new VertexTraits(0, 0, 0));
shape.Vertices.Add(new VertexTraits(0, 0.5, 0));
shape.Vertices.Add(new VertexTraits(0.5, 0.5, 0));
shape.Vertices.Add(new VertexTraits(0.5, 0, 0));
shape.Vertices.Add(new VertexTraits(0, 0, 0.5));
shape.Vertices.Add(new VertexTraits(0, 0.5, 0.5));
shape.Vertices.Add(new VertexTraits(0.5, 0.5, 0.5));
shape.Vertices.Add(new VertexTraits(0.5, 0, 0.5));
QuadMesh.Vertex[] faceVertices = new QuadMesh.Vertex[4];
faceVertices[0] = shape.Vertices[0];
faceVertices[1] = shape.Vertices[1];
faceVertices[2] = shape.Vertices[2];
faceVertices[3] = shape.Vertices[3];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[5];
faceVertices[1] = shape.Vertices[4];
faceVertices[2] = shape.Vertices[7];
faceVertices[3] = shape.Vertices[6];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[1];
faceVertices[1] = shape.Vertices[0];
faceVertices[2] = shape.Vertices[4];
faceVertices[3] = shape.Vertices[5];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[2];
faceVertices[1] = shape.Vertices[1];
faceVertices[2] = shape.Vertices[5];
faceVertices[3] = shape.Vertices[6];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[3];
faceVertices[1] = shape.Vertices[2];
faceVertices[2] = shape.Vertices[6];
faceVertices[3] = shape.Vertices[7];
shape.Faces.AddQuads(faceVertices);
faceVertices[0] = shape.Vertices[0];
faceVertices[1] = shape.Vertices[3];
faceVertices[2] = shape.Vertices[7];
faceVertices[3] = shape.Vertices[4];
shape.Faces.AddQuads(faceVertices);
//shape.Vertices.Add(new VertexTraits(0.25, 0.25, 0));
//shape.Vertices.Add(new VertexTraits(0, 0.25, 0));
//shape.Vertices.Add(new VertexTraits(0.25, 0, 0));
//faceVertices[0] = shape.Vertices[0];
//faceVertices[1] = shape.Vertices[3];
//faceVertices[2] = shape.Vertices[7];
//faceVertices[3] = shape.Vertices[4];
//shape.Faces.AddQuads(faceVertices);
//ChangTopolopy(shape);
return shape;
}
public QuadMesh CreatePlane(int column, int row)
{
QuadMesh shape = new QuadMesh();
for (int i = 0; i < row; i++)
{
for (int j = 0; j < column; j++)
{
shape.Vertices.Add(new VertexTraits((double)i / (double)row, (double)j / (double)column, 0));
}
}
QuadMesh.Vertex[] faceVertices = new QuadMesh.Vertex[4];
for (int i = 0; i < row - 1; i++)
{
for (int j = 0; j < column - 1; j++)
{
faceVertices[0] = shape.Vertices[i * column + j];
faceVertices[1] = shape.Vertices[i * column + j + 1];
faceVertices[2] = shape.Vertices[(i + 1) * column + j + 1];
faceVertices[3] = shape.Vertices[(i + 1) * column + j];
shape.Faces.AddQuads(faceVertices);
}
}
return shape;
}
private QuadMesh ChangeTopologyCatMullClark(QuadMesh sourceMesh)
{
QuadMesh newMesh = new QuadMesh();
//获得初始的点
for (int i = 0; i < sourceMesh.Vertices.Count; i++)
{
newMesh.Vertices.Add(new VertexTraits(sourceMesh.Vertices[i].Traits.Position.x, sourceMesh.Vertices[i].Traits.Position.y, sourceMesh.Vertices[i].Traits.Position.z));
}
//获得E点
Vector3D midPosition;
for (int i = 0; i < sourceMesh.Edges.Count; i++)
{
midPosition = (sourceMesh.Edges[i].Vertex0.Traits.Position +
sourceMesh.Edges[i].Vertex1.Traits.Position) / 2;
newMesh.Vertices.Add(new VertexTraits(midPosition.x, midPosition.y, midPosition.z));
}
//获得F点
foreach (QuadMesh.Face face in sourceMesh.Faces)
{
midPosition = (face.GetVertex(0).Traits.Position + face.GetVertex(1).Traits.Position + face.GetVertex(2).Traits.Position + face.GetVertex(3).Traits.Position) / 4;
newMesh.Vertices.Add(new VertexTraits(midPosition.x, midPosition.y, midPosition.z));
}
//构造面
foreach (QuadMesh.Face face in sourceMesh.Faces)
{
QuadMesh.Vertex vertex0 = newMesh.Vertices[face.GetVertex(3).Index];
QuadMesh.Vertex vertex1 = newMesh.Vertices[face.GetVertex(0).Index];
QuadMesh.Vertex vertex2 = newMesh.Vertices[face.GetVertex(1).Index];
QuadMesh.Vertex vertex3 = newMesh.Vertices[face.GetVertex(2).Index];
QuadMesh.Edge edge0 = face.GetVertex(0).FindEdgeTo(face.GetVertex(1));
QuadMesh.Edge edge1 = face.GetVertex(1).FindEdgeTo(face.GetVertex(2));
QuadMesh.Edge edge2 = face.GetVertex(2).FindEdgeTo(face.GetVertex(3));
QuadMesh.Edge edge3 = face.GetVertex(3).FindEdgeTo(face.GetVertex(0));
QuadMesh.Vertex midVertex0 = newMesh.Vertices[sourceMesh.Vertices.Count + edge0.Index];
QuadMesh.Vertex midVertex1 = newMesh.Vertices[sourceMesh.Vertices.Count + edge1.Index];
QuadMesh.Vertex midVertex2 = newMesh.Vertices[sourceMesh.Vertices.Count + edge2.Index];
QuadMesh.Vertex midVertex3 = newMesh.Vertices[sourceMesh.Vertices.Count + edge3.Index];
QuadMesh.Vertex FVertex = newMesh.Vertices[sourceMesh.Vertices.Count + sourceMesh.Edges.Count + face.Index];
QuadMesh.Vertex[] newFace = new QuadMesh.Vertex[4];
newFace[0] = vertex0;
newFace[1] = midVertex3;
newFace[2] = FVertex;
newFace[3] = midVertex2;
newMesh.Faces.AddQuads(newFace);
newFace[0] = midVertex2;
newFace[1] = FVertex;
newFace[2] = midVertex1;
newFace[3] = vertex3;
newMesh.Faces.AddQuads(newFace);
newFace[0] = midVertex3;
newFace[1] = vertex1;
newFace[2] = midVertex0;
newFace[3] = FVertex;
newMesh.Faces.AddQuads(newFace);
newFace[0] = FVertex;
newFace[1] = midVertex0;
newFace[2] = vertex2;
newFace[3] = midVertex1;
newMesh.Faces.AddQuads(newFace);
}
return newMesh;
}
private QuadMesh ChangeTopologyCatMullClark(QuadMesh sourceMesh)
{
QuadMesh newMesh = new QuadMesh();
//获得初始的点
for (int i = 0; i < sourceMesh.Vertices.Count; i++)
{
newMesh.Vertices.Add(new VertexTraits(sourceMesh.Vertices[i].Traits.Position.x, sourceMesh.Vertices[i].Traits.Position.y, sourceMesh.Vertices[i].Traits.Position.z));
}
//获得E点
Vector3D midPosition;
for (int i = 0; i < sourceMesh.Edges.Count; i++)
{
midPosition = (sourceMesh.Edges[i].Vertex0.Traits.Position +
sourceMesh.Edges[i].Vertex1.Traits.Position) / 2;
newMesh.Vertices.Add(new VertexTraits(midPosition.x, midPosition.y, midPosition.z));
}
//获得F点
foreach (QuadMesh.Face face in sourceMesh.Faces)
{
midPosition = (face.GetVertex(0).Traits.Position + face.GetVertex(1).Traits.Position + face.GetVertex(2).Traits.Position + face.GetVertex(3).Traits.Position) / 4;
newMesh.Vertices.Add(new VertexTraits(midPosition.x, midPosition.y, midPosition.z));
}
//构造面
foreach (QuadMesh.Face face in sourceMesh.Faces)
{
QuadMesh.Vertex vertex0 = newMesh.Vertices[face.GetVertex(3).Index];
QuadMesh.Vertex vertex1 = newMesh.Vertices[face.GetVertex(0).Index];
QuadMesh.Vertex vertex2 = newMesh.Vertices[face.GetVertex(1).Index];
QuadMesh.Vertex vertex3 = newMesh.Vertices[face.GetVertex(2).Index];
QuadMesh.Edge edge0 = face.GetVertex(0).FindEdgeTo(face.GetVertex(1));
QuadMesh.Edge edge1 = face.GetVertex(1).FindEdgeTo(face.GetVertex(2));
QuadMesh.Edge edge2 = face.GetVertex(2).FindEdgeTo(face.GetVertex(3));
QuadMesh.Edge edge3 = face.GetVertex(3).FindEdgeTo(face.GetVertex(0));
QuadMesh.Vertex midVertex0 = newMesh.Vertices[sourceMesh.Vertices.Count + edge0.Index];
QuadMesh.Vertex midVertex1 = newMesh.Vertices[sourceMesh.Vertices.Count + edge1.Index];
QuadMesh.Vertex midVertex2 = newMesh.Vertices[sourceMesh.Vertices.Count + edge2.Index];
QuadMesh.Vertex midVertex3 = newMesh.Vertices[sourceMesh.Vertices.Count + edge3.Index];
QuadMesh.Vertex FVertex = newMesh.Vertices[sourceMesh.Vertices.Count + sourceMesh.Edges.Count + face.Index];
QuadMesh.Vertex[] newFace = new QuadMesh.Vertex[4];
newFace[0] = vertex0;
newFace[1] = midVertex3;
newFace[2] = FVertex;
newFace[3] = midVertex2;
newMesh.Faces.AddQuads(newFace);
newFace[0] = midVertex2;
newFace[1] = FVertex;
newFace[2] = midVertex1;
newFace[3] = vertex3;
newMesh.Faces.AddQuads(newFace);
newFace[0] = midVertex3;
newFace[1] = vertex1;
newFace[2] = midVertex0;
newFace[3] = FVertex;
newMesh.Faces.AddQuads(newFace);
newFace[0] = FVertex;
newFace[1] = midVertex0;
newFace[2] = vertex2;
newFace[3] = midVertex1;
newMesh.Faces.AddQuads(newFace);
}
return(newMesh);
}
