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Modified: Tutte weights initialization for inner border vertices with valency-2. However such vertices can affect optimization.

This commit is contained in:
Hardik Jain 2020-03-28 16:26:56 +01:00 committed by hrdkjain@cordelia-ubuntu
parent c3da7a2201
commit ee9fcee717
1 changed files with 44 additions and 38 deletions
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82
Surface_mesh_parameterization/include/CGAL/Surface_mesh_parameterization/Iterative_authalic_parameterizer_3.h
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@ -234,53 +234,59 @@ protected:
neighborsCounter++;
}
// compute angles
for(int n=0; n<neighborsCounter; n++) {
int n_prev = (n==0 ? neighborsCounter-1 : n-1);
double theta = angle(NeighborList_[n].vector,NeighborList_[n_prev].vector);
NeighborList_[n].angle = theta;
theta_sum += theta;
}
// Normalise the angle
double factor = 2.0 / theta_sum;
factor *= M_PI;
for(int n=0; n<neighborsCounter; n++)
NeighborList_[n].angle *= factor;
NeighborList_[0].angle = 0.0;
for(int n=1; n<neighborsCounter; n++)
NeighborList_[n].angle += NeighborList_[n-1].angle;
for(int n=0; n<neighborsCounter; n++)
NeighborList_[n].uv = Point_2(NeighborList_[n].length*cos(NeighborList_[n].angle), NeighborList_[n].length*sin(NeighborList_[n].angle));
if (neighborsCounter < 2)
return ERROR_NON_TRIANGULAR_MESH;
if(neighborsCounter==2 && mesh.is_border(vertex)) {
std::cout << "Encountered inner border with valency-2 vertex (" << vertex << "), initializing with Tutte weights, this can affect optimization" << std::endl;
// Tutte weights
for(int k=0; k<neighborsCounter; k++)
NeighborList_[k].weight = 1.0;
}
else {
for(int n=0; n<neighborsCounter; n++) {
int n_prev = (n==0 ? neighborsCounter-1 : n-1);
double theta = angle(NeighborList_[n].vector,NeighborList_[n_prev].vector);
NeighborList_[n].angle = theta;
theta_sum += theta;
}
for(int j=0; j<neighborsCounter; j++)
{
/* Given the j-th neighbour of node i,
// Normalise the angle
double factor = 2.0 / theta_sum;
factor *= M_PI;
for(int n=0; n<neighborsCounter; n++)
NeighborList_[n].angle *= factor;
NeighborList_[0].angle = 0.0;
for(int n=1; n<neighborsCounter; n++)
NeighborList_[n].angle += NeighborList_[n-1].angle;
for(int n=0; n<neighborsCounter; n++)
NeighborList_[n].uv = Point_2(NeighborList_[n].length*cos(NeighborList_[n].angle), NeighborList_[n].length*sin(NeighborList_[n].angle));
for(int j=0; j<neighborsCounter; j++)
{
/* Given the j-th neighbour of node i,
find the two neighbours by intersecting the
line through nodes i and j with all segments of the polygon
made by the neighbours. Take the two neighbours on
either side. Only one segment intersects this line. */
for(int k=0; k<neighborsCounter; k++)
{
int kk = (k == neighborsCounter-1 ? 0 : k+1);
if(k == j || kk == j) continue;
double cross1 = determinant(NeighborList_[j].uv,NeighborList_[k].uv);
double cross2 = determinant(NeighborList_[j].uv,NeighborList_[kk].uv);
if(cross1 * cross2 <= 0.0)
for(int k=0; k<neighborsCounter; k++)
{
double tau0,tau1,tau2;
baryCoords0(NeighborList_[j].uv, NeighborList_[k].uv, NeighborList_[kk].uv, tau0, tau1, tau2);
NeighborList_[j].weight += tau0;
NeighborList_[k].weight += tau1;
NeighborList_[kk].weight += tau2;
break;
int kk = (k == neighborsCounter-1 ? 0 : k+1);
if(k == j || kk == j) continue;
double cross1 = determinant(NeighborList_[j].uv,NeighborList_[k].uv);
double cross2 = determinant(NeighborList_[j].uv,NeighborList_[kk].uv);
if(cross1 * cross2 <= 0.0)
{
double tau0,tau1,tau2;
baryCoords0(NeighborList_[j].uv, NeighborList_[k].uv, NeighborList_[kk].uv, tau0, tau1, tau2);
NeighborList_[j].weight += tau0;
NeighborList_[k].weight += tau1;
NeighborList_[kk].weight += tau2;
break;
}
}
}
}