public static void BoundaryShrink(TriMesh mesh)
{
List <List <TriMesh.HalfEdge> > holes = TriMeshUtil.RetrieveBoundaryEdgeAll(mesh);
foreach (var hole in holes)
{
foreach (var hf in hole)
{
TriMeshModify.RemoveVertex(hf.FromVertex);
}
}
}
public static void RepairSimpleHoles(TriMesh mesh)
{
List <List <TriMesh.HalfEdge> > holes = TriMeshUtil.RetrieveBoundaryEdgeAll(mesh);
foreach (List <TriMesh.HalfEdge> hole in holes)
{
for (int i = 2; i < hole.Count; i++)
{
mesh.Faces.AddTriangles(hole[0].ToVertex, hole[i - 1].ToVertex, hole[i].ToVertex);
}
}
TriMeshUtil.FixIndex(mesh);
}
public SparseMatrix BuildMatrixArea(TriMesh mesh)
{
List <List <TriMesh.HalfEdge> > bounds =
TriMeshUtil.RetrieveBoundaryEdgeAll(mesh);
int n = mesh.Vertices.Count;
SparseMatrix A = new SparseMatrix(2 * n, 2 * n);
foreach (List <TriMesh.HalfEdge> oneBoundary in bounds)
{
foreach (TriMesh.HalfEdge currentHF in oneBoundary)
{
int Vi = currentHF.FromVertex.Index;
int Vj = currentHF.ToVertex.Index;
A[2 * Vi, 2 * Vj + 1] += -0.5;
A[2 * Vj + 1, 2 * Vi] += -0.5;
A[2 * Vj, 2 * Vi + 1] += 0.5;
A[2 * Vi + 1, 2 * Vj] += 0.5;
}
}
return(A);
}
public static void BoundaryExpand(TriMesh mesh)
{
double length = TriMeshUtil.ComputeEdgeAvgLength(mesh);
List <List <TriMesh.HalfEdge> > holes = TriMeshUtil.RetrieveBoundaryEdgeAll(mesh);
foreach (var hole in holes)
{
TriMesh.Vertex[] arr = new HalfEdgeMesh.Vertex[hole.Count];
for (int i = 0; i < hole.Count; i++)
{
Vector3D normal = Vector3D.UnitX;
if (hole[i].Opposite.Face != null)
{
normal = TriMeshUtil.ComputeNormalFace(hole[i].Opposite.Face);
}
Vector3D toPos = hole[i].ToVertex.Traits.Position;
Vector3D fromPos = hole[i].FromVertex.Traits.Position;
Vector3D hfDir = toPos - fromPos;
Vector3D hfMid = (toPos + fromPos) / 2;
Vector3D pos = hfMid + normal.Cross(hfDir).Normalize() * length;
arr[i] = mesh.Vertices.Add(new VertexTraits(pos));
}
for (int i = 0; i < hole.Count; i++)
{
int next = (i + 1) % hole.Count;
TriMesh.Face face = mesh.Faces.Add(arr[i],
hole[i].ToVertex,
hole[next].ToVertex);
face.Traits.SelectedFlag = 1;
face = mesh.Faces.Add(arr[i],
hole[next].ToVertex,
arr[next]);
face.Traits.SelectedFlag = 1;
}
}
}
public static int CountBoundary(TriMesh mesh)
{
return(TriMeshUtil.RetrieveBoundaryEdgeAll(mesh).Count);
}
