void coarse(SurfaceMesh &mesh, double coarseRate, double flatRate, double denseWeight){
// TODO: Check if all polygons are closed (0)
std::cout << "Before coarsening: " << mesh.size<1>() << " " << mesh.size<2>() << " " << mesh.size<3>() << std::endl;
// Compute the average edge length
double avgLen = 0;
if (denseWeight > 0){
avgLen = surfacemesh_detail::getMeanEdgeLength(mesh);
}
double sparsenessRatio = 1;
double flatnessRatio = 1;
// Construct list of vertices to decimate
std::vector<SurfaceMesh::SimplexID<1> > toRemove;
for(auto vertexID : mesh.get_level_id<1>()){
// Sparseness as coarsening criteria
if(denseWeight > 0){
// Get max length of edges.
auto edges = mesh.up(vertexID);
double maxLen = 0;
for(auto edgeID : edges){
auto name = mesh.get_name(edgeID);
auto v = *mesh.get_simplex_down(edgeID, name[0])
- *mesh.get_simplex_down(edgeID, name[1]);
double tmpLen = std::sqrt(v|v);
if(tmpLen > maxLen) maxLen = tmpLen;
}
sparsenessRatio = std::pow(maxLen/avgLen, denseWeight);
}
// Curvature as coarsening criteria
if(flatRate > 0){
auto lst = surfacemesh_detail::computeLocalStructureTensor(mesh, vertexID, RINGS);
auto eigenvalues = surfacemesh_detail::getEigenvalues(lst).eigenvalues();
// The closer this ratio is to 0 the flatter the local region.
flatnessRatio = std::pow(eigenvalues[1]/eigenvalues[2], flatRate);
}
// Add vertex to delete list
if(sparsenessRatio * flatnessRatio < coarseRate){
toRemove.push_back(vertexID);
}
}
std::cout << toRemove.size() << " vertices are marked to be removed." << std::endl;
for(auto vertexID : toRemove){
surfacemesh_detail::decimateVertex(mesh, vertexID);
}
std::cout << "After coarsening: " << mesh.size<1>() << " " << mesh.size<2>() << " " << mesh.size<3>() << std::endl;
}
void coarseIT(SurfaceMesh &mesh, double coarseRate, double flatRate, double denseWeight){
std::cout << "Before coarsening: " << mesh.size<1>() << " " << mesh.size<2>() << " " << mesh.size<3>() << std::endl;
// Compute the average edge length
double avgLen = 0;
if (denseWeight > 0){
avgLen = surfacemesh_detail::getMeanEdgeLength(mesh);
}
double sparsenessRatio = 1;
double flatnessRatio = 1;
// Backup vertices so we can modify in place
auto range = mesh.get_level_id<1>();
const std::vector<SurfaceMesh::SimplexID<1> > Vertices(range.begin(), range.end());
for(auto vertexID : Vertices) {
// Sparseness as coarsening criteria
if(denseWeight > 0){
// Get max length of edges.
auto edges = mesh.up(vertexID);
double maxLen = 0;
for(auto edgeID : edges){
auto name = mesh.get_name(edgeID);
auto v = *mesh.get_simplex_down(edgeID, name[0])
- *mesh.get_simplex_down(edgeID, name[1]);
double tmpLen = std::sqrt(v|v);
if(tmpLen > maxLen) maxLen = tmpLen;
}
sparsenessRatio = std::pow(maxLen/avgLen, denseWeight);
}
// Curvature as coarsening criteria
if(flatRate > 0){
auto lst = surfacemesh_detail::computeLocalStructureTensor(mesh, vertexID, RINGS);
auto eigenvalues = surfacemesh_detail::getEigenvalues(lst).eigenvalues();
// The closer this ratio is to 0 the flatter the local region.
flatnessRatio = std::pow(eigenvalues[1]/eigenvalues[2], flatRate);
}
// Check if we should delete
if(sparsenessRatio * flatnessRatio < coarseRate){
surfacemesh_detail::decimateVertex(mesh, vertexID);
}
}
std::cout << "After coarsening: " << mesh.size<1>() << " " << mesh.size<2>() << " " << mesh.size<3>() << std::endl;
}
