int main()
{
std::vector<Point_3> points;
points.push_back(Point_3(2.0f, 3.535533905932738f, 3.535533905932737f));
points.push_back(Point_3(4.0f, 2.0f, 0.0f));
points.push_back(Point_3(0.0f, 2.0f, 0.0f));
points.push_back(Point_3(1.0f, 0.0f, 0.0f));
points.push_back(Point_3(4.0f, 1.414213562373095f, 1.414213562373095f));
points.push_back(Point_3(0.0f, 1.414213562373095f, 1.414213562373095f));
points.push_back(Point_3(3.0f, 0.0f, 0.0f));
points.push_back(Point_3(2.0f, 5.0f, 0.0f));
Polyhedron P;
CGAL::convex_hull_3(points.begin(), points.end(), P);
std::cout << "- Number of vertices = " << P.size_of_vertices() << std::endl;
std::cout << "- Number of edges = " << P.size_of_halfedges()/2 << std::endl;
std::cout << "- Number of faces = " << P.size_of_facets() << std::endl;
for ( Facet_iterator i = P.facets_begin(); i != P.facets_end(); ++i)
{
Halfedge_facet_circulator j = i->facet_begin();
CGAL_assertion( CGAL::circulator_size(j) >= 3);
std::cout << CGAL::circulator_size(j) << ' ';
do{
//std::cout << ' ' << std::distance(P.vertices_begin(), j->vertex());
std::cout << " (" << j->vertex()->point().x() << ' ' << j->vertex()->point().y() << ' ' << j->vertex()->point().z() << ')' << ", ";
} while ( ++j != i->facet_begin());
std::cout << std::endl;
}
return 0;
}
void Polyhedron_demo_mesh_simplification_plugin::on_actionSimplify_triggered()
{
const CGAL::Three::Scene_interface::Item_id index = scene->mainSelectionIndex();
Scene_polyhedron_item* item =
qobject_cast<Scene_polyhedron_item*>(scene->item(index));
if(item)
{
Polyhedron* pMesh = item->polyhedron();
// get option (#edges)
bool ok;
const int nb_edges =
QInputDialog::getInt(mw, tr("Stop condition"),
tr("Number of edges:"),
(int)(pMesh->size_of_halfedges () / 4), // default value: current #edges / 2
3, // min = one triangle
(int)pMesh->size_of_halfedges(), // max #edges
1, // step for the spinbox
&ok);
// check user cancellation
if(!ok)
return;
// simplify
QTime time;
time.start();
std::cout << "Simplify...";
QApplication::setOverrideCursor(Qt::WaitCursor);
namespace SMS = CGAL::Surface_mesh_simplification;
SMS::Count_stop_predicate< Polyhedron > stop(nb_edges); // target #edges
SMS::edge_collapse( *pMesh, stop,
CGAL::parameters::vertex_index_map(get(CGAL::vertex_external_index,*pMesh))
.halfedge_index_map(get(CGAL::halfedge_external_index,*pMesh)));
std::cout << "ok (" << time.elapsed() << " ms, "
<< pMesh->size_of_halfedges() / 2 << " edges)" << std::endl;
// update scene
item->invalidate_buffers();
scene->itemChanged(index);
QApplication::restoreOverrideCursor();
}
}
//------------------------------------------------------------------------------
// Compute and store the results of dual graphs into appropriate variables
//
// computeDual( mesh, whole, bary, mid );
//------------------------------------------------------------------------------
void computeDual( Polyhedron & poly, Graph & dual,
vector< Point3 > & bary, vector< Point3 > & mid )
{
// initialize the array of face barycenters: refer to the point at which the gravitational forces exerted by 2 objects are equal
bary.clear();
bary.resize( poly.size_of_facets() );
// initialize the dual graph with dual vertices
dual.clear();
int fid = 0;
for ( Facet_iterator fi = poly.facets_begin(); fi != poly.facets_end(); ++fi ) {
// add a vertex: each face equals to each dual vertex
add_vertex( dual );
bary[ fid++ ] = fi->center();
// cerr << " Barycenter No. " << fid-1 << " : " << bary[ fid-1 ] << endl;
}
int size_of_edges = poly.size_of_halfedges() / 2; //redundant
// initialize the array of midpoints
mid.clear();
mid.resize( size_of_edges );
// initialize the array of lengths
// length.clear();
// length.resize( size_of_edges );
// construct the connecitivity of the dual graph
for ( Halfedge_iterator hi = poly.halfedges_begin(); hi != poly.halfedges_end(); ++hi ) {
int origID = hi->facet()->id(); // the face
int destID = hi->opposite()->facet()->id(); // the neighbor face
Point3 origCoord = hi->vertex()->point();
Point3 destCoord = hi->opposite()->vertex()->point();
Vector3 dispVec = origCoord - destCoord;
Point3 midCoord = destCoord + 0.5 * dispVec;
// double curLength = sqrt( dispVec.squared_length() ); // the length between two connected vertices
#ifdef DEBUG
cerr << origID << " -- " << destID << endl;
#endif // DEBUG
if ( origID < destID )
add_edge( origID, destID, hi->id(), dual );
mid[ hi->id() ] = midCoord;
hi->mid() = hi->opposite()->mid() = midCoord;
hi->weight() = hi->opposite()->weight() = 1.0;
}
}
// a helper method for running different iterators
void running_iterators( Polyhedron& P) {
if ( P.size_of_facets() == 0)
return;
std::size_t nv = P.size_of_vertices();
std::cout << "The number of vertices in the Polyhedron: " << nv << std::endl;
std::cout << "The number of facets in the Polyhedron: " << P.size_of_facets() << std::endl;
std::cout << "The number of half edges in the Polyhedron: " << P.size_of_halfedges() << std::endl;
std::cout << std:: endl;
Polyhedron::Vertex_iterator last_v = P.vertices_end();
-- last_v; // the last of the old vertices
Polyhedron::Edge_iterator last_e = P.edges_end();
-- last_e; // the last of the old edges
Polyhedron::Facet_iterator last_f = P.facets_end();
-- last_f; // the last of the old facets
int k = 0;
Polyhedron::Facet_iterator f = P.facets_begin();
do {
std::cout << "Printing a facet index: " << k++ << std::endl;
f->halfedge();
} while ( f++ != last_f);
std::cout << std::endl;
// -------------------------------------------------
// traverse the vertices
// -------------------------------------------------
std::cout << "Printing the vertex indices: " << std::endl;
int n=0;
for (Polyhedron::Vertex_iterator vi = P.vertices_begin(); vi != P.vertices_end(); ++vi)
{
Kernel::Point_3 p;
p = vi->point();
std::cout << "Vertex index: " << n++ << std::endl;
std::cout << "p.x() = " << p.x() << std::endl;
std::cout << "p.y() = " << p.y() << std::endl;
std::cout << "p.z() = " << p.z() << std::endl;
}
std::cout << std::endl;
// -------------------------------------------------
// traverse the edges
// -------------------------------------------------
std::cout << "Iterating over the edges.... " << std::endl;
n=0;
for (Polyhedron::Edge_iterator ei = P.edges_begin(); ei != P.edges_end(); ++ei)
{
ei->next();
Kernel::Point_3 p;
p = ei->vertex()->point();
std::cout << "For edge index: " << n++ << std::endl;
std::cout << "p.x() = " << p.x() << std::endl;
std::cout << "p.y() = " << p.y() << std::endl;
std::cout << "p.z() = " << p.z() << std::endl;
}
std::cout << std::endl;
// -----------------------------------------------
// Do something else with the edge iterators
// -----------------------------------------------
Polyhedron::Edge_iterator e = P.edges_begin();
++ last_e; // make it the past-the-end position again
while ( e != last_e) {
Polyhedron::Halfedge_handle h = e;
++e;
};
CGAL_postcondition( P.is_valid());
}
TrianglesList meshSimplification(TrianglesList &triangles, int stopPredicate) {
#ifdef MESHSIMPLIFICATION_LOG
CGAL::Timer timer;
timer.start();
#endif
TrianglesList result;
try
{
Polyhedron P;
#ifdef MESHSIMPLIFICATION_LOG
std::cout << "Start Building Polyhedron surface... " << std::endl;
#endif
Build_triangle_mesh_coherent_surface<HalfedgeDS> triangle(triangles);
P.delegate(triangle);
P.normalize_border();
#ifdef MESHSIMPLIFICATION_LOG
std::cout << "Completed Building Polyhedron surface:" << std::endl;
std::cout << "Polyhedron is_pure_triangle: " << P.is_pure_triangle() << std::endl;
std::cout << "Polyhedron is_closed: " << P.is_closed() << std::endl;
std::cout << "Polyhedron is_pure_bivalent : " << P.is_pure_bivalent () << std::endl;
std::cout << "Polyhedron is_pure_trivalent: " << P.is_pure_trivalent() << std::endl;
std::cout << "Polyhedron is_valid 0: " << P.is_valid(false, 0) << std::endl;
std::cout << "Polyhedron is_valid 1: " << P.is_valid(false, 1) << std::endl;
std::cout << "Polyhedron is_valid 2: " << P.is_valid(false, 2) << std::endl;
std::cout << "Polyhedron is_valid 3: " << P.is_valid(false, 3) << std::endl;
std::cout << "Polyhedron is_valid 4: " << P.is_valid(false, 4) << std::endl;
std::cout << "Polyhedron normalized_border_is_valid : " << P.normalized_border_is_valid(false) << std::endl;
#endif
#ifdef MESHSIMPLIFICATION_LOG
std::cout << "Start edge_collapse... " << std::endl;
#endif
SMS::Count_stop_predicate<Polyhedron> stop(stopPredicate);
int removedEdges = SMS::edge_collapse(P, stop,
CGAL::vertex_index_map(boost::get(CGAL::vertex_external_index, P)).edge_index_map(boost::get(CGAL::edge_external_index ,P))
);
#ifdef MESHSIMPLIFICATION_LOG
std::cout << "Completed edge_collapse:" << std::endl;
std::cout << "Finished with: " << removedEdges << " edges removed and " << (P.size_of_halfedges()/2) << " final edges." << std::endl;
#endif
//Build output result
for ( Polyhedron::Facet_iterator fit( P.facets_begin() ), fend( P.facets_end() ); fit != fend; ++fit )
{
if ( fit->is_triangle() )
{
PointCGAL verts[3];
int tick = 0;
Polyhedron::Halfedge_around_facet_circulator hit( fit->facet_begin() ), hend( hit );
do
{
if ( tick < 3 )
{
verts[tick++] = PointCGAL( hit->vertex()->point().x(), hit->vertex()->point().y(), hit->vertex()->point().z() );
}
else
{
std::cout << "meshSimplification: We've got facets with more than 3 vertices even though the facet reported to be triangular..." << std::endl;
}
} while( ++hit != hend );
result.push_back( Triangle(verts[0], verts[1], verts[2]) );
}
else
{
std::cout << "meshSimplification: Skipping non-triangular facet" << std::endl;
}
}
}
catch (CGAL::Assertion_exception e)
{
std::cout << "ERROR: meshSimplification CGAL::Assertion_exception" << e.message() << std::endl;
}
#ifdef MESHSIMPLIFICATION_LOG
timer.stop();
std::cout << "meshSimplification result with: " << result.size() << " triangles." << std::endl;
std::cout << "Total meshSimplification time: " << timer.time() << std::endl;
#endif
return result;
}
void mergeCoplanar(Polyhedron& p,bool step2) {
int facetsBefore = p.size_of_facets();
p.normalize_border();
if(!p.size_of_border_halfedges()) {
// Calculate normals only once in advace! so all tris should be coplanar with the original
std::transform( p.facets_begin(), p.facets_end(),p.planes_begin(),Plane_equation()); // Calculate plane equations (only works on tri<- = bs)=true
bool coplanarFound = true;
std::vector<Polyhedron::Halfedge_handle> skipHEs;
while (coplanarFound) {
coplanarFound = false; // Set coplanarFound false
int percCount = 1;
for (Polyhedron::Halfedge_iterator hit = p.halfedges_begin(); hit != p.halfedges_end(); ++hit,++percCount){ // Loop through all halfedges
if (is_coplanar(hit,true)){ // If coplanar and equals semantics
Polyhedron::Halfedge_handle removeMe = hit;
while (CGAL::circulator_size(removeMe->vertex_begin()) < 3) // Mover handle to beginning of linestring
removeMe = removeMe->next();
bool jcnh = false;
if (!step2) jcnh = joinCreatesNoHole (hit);
else jcnh = joinCreatesNoHole2(hit);
if (jcnh){ // If no holes will be created
std::cout << "\rFacets before/after: "<<facetsBefore<<" -> "<< p.size_of_facets()<<". ("<<100*percCount/p.size_of_halfedges()<<"%)";
while (CGAL::circulator_size(removeMe->opposite()->vertex_begin()) < 3) // Join vertexes until at the other end of linestring
if (removeMe->facet_degree()>3 && removeMe->opposite()->facet_degree()>3)
removeMe = (p.join_vertex(removeMe))->next()->opposite();
else // One of the faces turned into a triangle ->remove center vertex
break;
if (CGAL::circulator_size(removeMe->opposite()->vertex_begin()) < 3) // Remove remained of the border
p.erase_center_vertex(removeMe->opposite()); // if two segments remain remove center point
else
p.join_facet(removeMe); // if one segment remains join facets
coplanarFound = true;
break;
} else { // simplify border, but how to do this safely? not optimal solution implemented. Should do: add inward offseted point of intersection etc.
if (std::find(skipHEs.begin(), skipHEs.end(),hit)!=skipHEs.end()) { // Skip if hit in skipList
while (CGAL::circulator_size(removeMe->opposite()->vertex_begin()) < 3) { // Join vertexes until at the other end of linestring
if (removeMe->facet_degree()>3 && removeMe->opposite()->facet_degree()>3)
if (triDoesNotIntersectFacet(removeMe)) // if tri reMe,reME->prev does not intersect left or right facet
removeMe = (p.join_vertex(removeMe))->next()->opposite(); // remove removeME
else {
skipHEs.push_back(removeMe);
skipHEs.push_back(removeMe->opposite());
removeMe = removeMe->prev(); // move removeME one halfedge back
}
else break; // stop if only a triangle remains or at other end
}
skipHEs.push_back(removeMe);
skipHEs.push_back(removeMe->opposite());
} } } } } }
//if (!step2) mergeCoplanar(p,true);
//else
std::cout << "\rFacets before/after: "<<facetsBefore<<" -> "<< p.size_of_facets()<<". (100%)"<<std::endl;
}
void mergeColinear(Polyhedron& p) {
int vertBefore = p.size_of_vertices();
bool colinearFound = true;
while (colinearFound) {
colinearFound = false; // Set temporarily to false, if merge degments then set true
int percCount = 1;
for (Polyhedron::Halfedge_iterator hit = p.halfedges_begin(); hit != p.halfedges_end(); ++hit,++percCount){
if (CGAL::circulator_size(hit->vertex_begin()) == 1) {
std::cerr << "WARNING: Loose edge, but how??"<<std::endl;
while (CGAL::circulator_size(hit->vertex_begin()) == 1)
hit = p.join_vertex(hit->opposite());
break;
}
if ((CGAL::circulator_size(hit->vertex_begin()) == 2) && // if only two he connected to vertex
(hit->facet_degree()>3 && hit->opposite()->facet_degree()>3)) { // if faces are not triangles // prob faster
Vector_3 cur(hit->prev()->vertex()->point(),hit->vertex()->point());
Vector_3 nex(hit->vertex()->point(),hit->next()->vertex()->point());
if ( is_colinear(cur,nex)) { // check if colinear
std::cout << "\rVertices before/after: "<<vertBefore<<" -> "<< p.size_of_vertices()<<". ("<<100*percCount/p.size_of_halfedges()<<"%)";
p.join_vertex(hit->opposite()); // move cur to prev point
colinearFound = true;
break;
} } } }
std::cout << "\rVertices before/after: "<<vertBefore<<" -> "<< p.size_of_vertices()<<". (100%)" << std::endl;
}
