public static double[][] ComputeUniformLap(ref NonManifoldMesh mesh)
{
SparseMatrix L = MeshOperators.BuildUniformMatrixL(ref mesh);
if (L == null)
{
throw new Exception("Laplacian matrix is null");
}
int n = mesh.VertexCount;
double[] v = new double[n];
double[][] lap = new double[3][];
for (int i = 0; i < 3; i++)
{
lap[i] = new double[n];
for (int j = 0, k = 0; j < n; j++, k += 3)
{
v[j] = mesh.VertexPos[k + i];
}
L.Multiply(v, 0, lap[i], 0);
}
return(lap);
}
public static SparseMatrix CreateMatrixATA(ref SparseMatrix A, ref NonManifoldMesh mesh)
{
// assume A is sorted
// assume values in parameter adj is in order
if (A == null)
{
throw new Exception("A matrix is null");
}
int[][] adj = MeshOperators.BuildTwoRingVV(ref mesh).GetRowIndex();
int n = A.ColumnSize;
SparseMatrix ATA = new SparseMatrix(n, n);
for (int i = 0; i < n; i++)
{
List <SparseMatrix.Element> col1 = A.GetColumn(i);
foreach (int j in adj[i])
{
List <SparseMatrix.Element> col2 = A.GetColumn(j);
int c1 = 0, c2 = 0;
double sum = 0.0;
bool used = false;
while (c1 < col1.Count && c2 < col2.Count)
{
if (col1[c1].i < col2[c2].i)
{
c1++; continue;
}
if (col1[c1].i > col2[c2].i)
{
c2++; continue;
}
sum += col1[c1].value * col2[c2].value;
used = true;
c1++;
c2++;
}
if (used)
{
ATA.AddElement(i, j, sum);
}
}
}
if (ATA.IsSymmetric() == false)
{
throw new Exception("ATA is not symmetric!!");
}
return(ATA);
}
public void DrawLapCoord(NonManifoldMesh mesh)
{
GL.LineWidth(2.0f);
GL.Color3(1.0, 0.0, 0.0);
GL.Begin(BeginMode.Lines);
double[] lapCoordiante = MeshOperators.ComputeDualLap(ref mesh);
for (int i = 0, j = 0; i < mesh.FaceCount; i++, j += 3)
{
GraphicResearchHuiZhao.Vector3D u = mesh.GetDualPosition(i);
GraphicResearchHuiZhao.Vector3D lap = new GraphicResearchHuiZhao.Vector3D(lapCoordiante[j], lapCoordiante[j + 1], lapCoordiante[j + 2]);
GraphicResearchHuiZhao.Vector3D v = u + 3.0 * lap;
GL.Vertex3(u.x, u.y, u.z);
GL.Vertex3(v.x, v.y, v.z);
}
GL.End();
}
public static void SetMeshColorToGaussianCurvature(NonManifoldMesh mesh)
{
double[] gaussianCurvature = MeshOperators.ComputeGaussianCurvature(ref mesh);
UpdateColor(ref mesh, ref gaussianCurvature);
}
public static double[] GaussianCurvatureArray(NonManifoldMesh mesh)
{
return(MeshOperators.ComputeGaussianCurvature(ref mesh));
}
public static void SetMeshColorToPricipal2(NonManifoldMesh mesh)
{
double[][] pricipal = MeshOperators.ComputePricipalCurvature(ref mesh);
UpdateColor(ref mesh, ref pricipal[1]);
}