Nef_polyhedron build_axes() {
Nef_nary_union unioner;
{
debug(LOG_DEBUG, DEBUG_LOG, 0, "add X-axis");
Polyhedron p;
Build_Arrow b(point(-0.1, 0, 0),
point(4.1, 0, 0), arrowdiameter, 16);
p.delegate(b);
unioner.add_polyhedron(p);
}
{
debug(LOG_DEBUG, DEBUG_LOG, 0, "add Y-axis");
Polyhedron p;
Build_Arrow b(point(0, -2, 0),
point(0, 2, 0), arrowdiameter, 16);
p.delegate(b);
unioner.add_polyhedron(p);
}
{
debug(LOG_DEBUG, DEBUG_LOG, 0, "add Z-axis");
Polyhedron p;
Build_Arrow b(point(0, 0, -2),
point(0, 0, 2), arrowdiameter, 16);
p.delegate(b);
unioner.add_polyhedron(p);
}
debug(LOG_DEBUG, DEBUG_LOG, 0, "extract axes union");
return unioner.get_union();
}
int main() {
Polyhedron P;
Build_triangle<HalfedgeDS> triangle;
P.delegate( triangle);
CGAL_assertion( P.is_triangle( P.halfedges_begin()));
return 0;
}
Polyhedron generate_polyhedron(
const MatrixFr& vertices, const MatrixIr& faces) {
Polyhedron P;
PolyhedronBuilder<HalfedgeDS> triangle(vertices, faces);
P.delegate(triangle);
assert(vertices.rows() == P.size_of_vertices());
assert(faces.rows() == P.size_of_facets());
return P;
}
Nef_polyhedron build_support(double thickness) {
if (!yzslicing) {
CartesianDomain domain(Interval(-2, 2), Interval(0, 1));
CharSupport support;
Build_CartesianPointFunction s(support,
domain, 4 * steps, 2, thickness);
Polyhedron p;
p.delegate(s);
return Nef_polyhedron(p);
} else {
CartesianDomain domain(Interval(0, 4), Interval(0, 2));
SupportSheet support;
Build_CartesianPointFunction s(support,
domain, steps, steps, thickness);
Polyhedron p;
p.delegate(s);
return Nef_polyhedron(p);
}
}
Nef_polyhedron polyhedron_to_cgal( const polyhedron &p ){
polyhedron tmp = p.triangulate();
Polyhedron P;
polyhedron_builder<HalfedgeDS> builder( tmp );
P.delegate( builder );
if( P.is_closed() )
return Nef_polyhedron( P );
else
std::cout << "input polyhedron is not closed!" << std::endl;
return Nef_polyhedron();
}
int main()
{
std::stringstream ss;
ss << "\
OFF\n6 4 0\n\
0 1 0\n\
0 0 0\n\
1 0 0\n\
1 1 0\n\
2 1 0\n\
2 0 0\n\
3 0 1 2\n\
3 0 2 3\n\
3 2 5 3\n\
3 5 4 3\n";
Polyhedron P;
ss >> P;
assert( P.size_of_vertices() == 6);
assert( P.size_of_facets() == 4);
assert( P.is_valid() );
//consider vertex 3 and set its halfedge to be on the border
Polyhedron::Vertex_iterator vit=P.vertices_begin();
std::advance(vit, 3);
assert( vit->point() == K::Point_3(1, 1, 0) );
Polyhedron::Halfedge_handle h=vit->halfedge();
while ( !h->is_border() )
h=h->next()->opposite();
vit->VBase::set_halfedge(h);
assert( vit->halfedge()->vertex() == vit );
//consider vertex 4 and set its halfedge to be on the border
++vit;
assert( vit->point() == K::Point_3(2, 1, 0) );
h=vit->halfedge();
while ( !h->is_border() )
h=h->next()->opposite();
vit->VBase::set_halfedge(h);
assert( vit->halfedge()->vertex() == vit );
//try to append a facet
Appender modifier;
P.delegate(modifier);
assert( P.size_of_vertices() == 7);
assert( P.size_of_facets() == 5);
assert( P.is_valid() );
}
int main() {
Polyhedron P;
Build_triangle<HalfedgeDS> triangle;
P.delegate( triangle);
CGAL_assertion( P.is_triangle( P.halfedges_begin()));
CGAL::set_pretty_mode(std::cout);
std::cout << "Success creating two triangles: "
<< std::endl;
std::cout << "The polyhedron created at this stage" << P << std::endl;
running_iterators(P);
return 0;
}
// Constructeur : Charge l'obj et génère les Polyhedron_3 associés
DegradeAnObject::DegradeAnObject(char const *input, char const *output) {
this->output = output;
// load the input file
load_obj(input);
if( coords.size() == 0 ) {
std::cout << "Aucun objet n'a été chargé" << std::endl;
}
else {
std::cout << "objet chargé" << std::endl;
// build polyhedrons from the loaded arrays
for(int i = 0 ; i < names.size() ; i++) {
Polyhedron P;
polyhedron_builder<HalfedgeDS> builder( coords[i], faces[i], minFacets[i] );
P.delegate( builder );
polys.push_back(P);
}
}
}
scalarField calcCurvature(const triSurface& surf)
{
scalarField k(surf.points().size(), 0);
Polyhedron P;
buildCGALPolyhedron convert(surf);
P.delegate(convert);
// Info<< "Created CGAL Polyhedron with " << label(P.size_of_vertices())
// << " vertices and " << label(P.size_of_facets())
// << " facets. " << endl;
// The rest of this function adapted from
// CGAL-3.7/examples/Jet_fitting_3/Mesh_estimation.cpp
//Vertex property map, with std::map
typedef std::map<Vertex*, int> Vertex2int_map_type;
typedef boost::associative_property_map< Vertex2int_map_type >
Vertex_PM_type;
typedef T_PolyhedralSurf_rings<Polyhedron, Vertex_PM_type > Poly_rings;
typedef CGAL::Monge_via_jet_fitting<Kernel> Monge_via_jet_fitting;
typedef Monge_via_jet_fitting::Monge_form Monge_form;
std::vector<Point_3> in_points; //container for data points
// default parameter values and global variables
unsigned int d_fitting = 2;
unsigned int d_monge = 2;
unsigned int min_nb_points = (d_fitting + 1)*(d_fitting + 2)/2;
//initialize the tag of all vertices to -1
Vertex_iterator vitb = P.vertices_begin();
Vertex_iterator vite = P.vertices_end();
Vertex2int_map_type vertex2props;
Vertex_PM_type vpm(vertex2props);
CGAL_For_all(vitb, vite)
{
put(vpm, &(*vitb), -1);
}
/*
* mexFunction(): entry point for the mex function
*/
void mexFunction(int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[]) {
// interface to deal with input arguments from Matlab
enum InputIndexType {IN_TRI, IN_X, IN_METHOD, IN_ITER, InputIndexType_MAX};
MatlabImportFilter::Pointer matlabImport = MatlabImportFilter::New();
matlabImport->ConnectToMatlabFunctionInput(nrhs, prhs);
// check that we have all input arguments
matlabImport->CheckNumberOfArguments(2, InputIndexType_MAX);
// register the inputs for this function at the import filter
MatlabInputPointer inTRI = matlabImport->RegisterInput(IN_TRI, "TRI");
MatlabInputPointer inX = matlabImport->RegisterInput(IN_X, "X");
MatlabInputPointer inMETHOD = matlabImport->RegisterInput(IN_METHOD, "METHOD");
MatlabInputPointer inITER = matlabImport->RegisterInput(IN_ITER, "ITER");
// interface to deal with outputs to Matlab
enum OutputIndexType {OUT_TRI, OUT_N, OutputIndexType_MAX};
MatlabExportFilter::Pointer matlabExport = MatlabExportFilter::New();
matlabExport->ConnectToMatlabFunctionOutput(nlhs, plhs);
// check number of outputs the user is asking for
matlabExport->CheckNumberOfArguments(0, OutputIndexType_MAX);
// register the outputs for this function at the export filter
typedef MatlabExportFilter::MatlabOutputPointer MatlabOutputPointer;
MatlabOutputPointer outTRI = matlabExport->RegisterOutput(OUT_TRI, "TRI");
MatlabOutputPointer outN = matlabExport->RegisterOutput(OUT_N, "N");
// if any of the inputs is empty, the output is empty too
if (mxIsEmpty(prhs[IN_TRI]) || mxIsEmpty(prhs[IN_X])) {
matlabExport->CopyEmptyArrayToMatlab(outTRI);
matlabExport->CopyEmptyArrayToMatlab(outN);
return;
}
// polyhedron to contain the input mesh
Polyhedron mesh;
PolyhedronBuilder<Polyhedron> builder(matlabImport, inTRI, inX);
mesh.delegate(builder);
// get size of input matrix with the points
mwSize nrowsTri = mxGetM(inTRI->pm);
mwSize nrowsX = mxGetM(inX->pm);
#ifdef DEBUG
std::cout << "Number of facets read = " << mesh.size_of_facets() << std::endl;
std::cout << "Number of vertices read = " << mesh.size_of_vertices() << std::endl;
#endif
if (nrowsTri != mesh.size_of_facets()) {
mexErrMsgTxt(("Input " + inTRI->name + ": Number of triangles read into mesh different from triangles provided at the input").c_str());
}
if (nrowsX != mesh.size_of_vertices()) {
mexErrMsgTxt(("Input " + inX->name + ": Number of vertices read into mesh different from vertices provided at the input").c_str());
}
// sort halfedges such that the non-border edges precede the
// border edges. We need to do this before any halfedge iterator
// operations are valid
mesh.normalize_border();
#ifdef DEBUG
std::cout << "Number of border halfedges = " << mesh.size_of_border_halfedges() << std::endl;
#endif
// number of holes we have filled
mwIndex n = 0;
// a closed mesh with no holes will have no border edges. What we do
// is grab a border halfedge and close the associated hole. This
// makes the rest of the iterators invalid, so we have to normalize
// the mesh again. Then we iterate, looking for a new border
// halfedge, filling the hole, etc.
//
// Note that confusingly, mesh.border_halfedges_begin() gives a
// pointer to the halfedge that is NOT a border in a border
// edge. The border halfedge is instead
// mesh.border_halfedges_begin()->opposite()
while (!mesh.is_closed()) {
// exit if user pressed Ctrl+C
ctrlcCheckPoint(__FILE__, __LINE__);
// get the first hole we can find, and close it
mesh.fill_hole(mesh.border_halfedges_begin()->opposite());
// increase the counter of number of holes we have filled
n++;
// renormalize mesh so that halfedge iterators are again valid
mesh.normalize_border();
}
// split all facets to triangles
CGAL::triangulate_polyhedron<Polyhedron>(mesh);
// copy output with number of holes filled
std::vector<double> nout(1, n);
matlabExport->CopyVectorOfScalarsToMatlab<double, std::vector<double> >(outN, nout, 1);
// allocate memory for Matlab outputs
double *tri = matlabExport->AllocateMatrixInMatlab<double>(outTRI, mesh.size_of_facets(), 3);
// extract the triangles of the solution
// snippet adapted from CgalMeshSegmentation.cpp
// vertices coordinates. Assign indices to the vertices by defining
// a map between their handles and the index
std::map<Vertex_handle, int> V;
int inum = 0;
for(Vertex_iterator vit = mesh.vertices_begin(); vit != mesh.vertices_end(); ++vit) {
// save to internal list of vertices
V[vit] = inum++;
}
// triangles given as (i,j,k), where each index corresponds to a vertex in x
mwIndex row = 0;
for (Facet_iterator fit = mesh.facets_begin(); fit != mesh.facets_end(); ++fit, ++row) {
if (fit->facet_degree() != 3) {
std::cerr << "Facet has " << fit->facet_degree() << " edges" << std::endl;
mexErrMsgTxt("Facet does not have 3 edges");
}
// go around the half-edges of the facet, to extract the vertices
Halfedge_around_facet_circulator heit = fit->facet_begin();
int idx = 0;
do {
// extract triangle indices and save to Matlab output
// note that Matlab indices go like 1, 2, 3..., while C++ indices go like 0, 1, 2...
tri[row + idx * mesh.size_of_facets()] = 1 + V[heit->vertex()];
idx++;
} while (++heit != fit->facet_begin());
}
}
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;
}
/**
* \brief main function for example6
*/
int main(int argc, char *argv[]) {
int c;
while (EOF != (c = getopt(argc, argv, "dSACIXNPFxp:")))
switch (c) {
case 'd':
if (debuglevel == LOG_DEBUG) {
debuglevel++;
} else {
debuglevel = LOG_DEBUG;
}
break;
case 'S':
show_solution = !show_solution;
break;
case 'A':
show_alternatives = !show_alternatives;
break;
case 'C':
show_characteristics = !show_characteristics;
break;
case 'I':
show_initial = !show_initial;
break;
case 'X':
show_axes = !show_axes;
break;
case 'N':
show_negative = !show_negative;
break;
case 'F':
show_fcurve = !show_fcurve;
break;
case 'P':
show_support = !show_support;
break;
case 'p':
prefix = std::string(optarg);
break;
case 'x':
yzslicing = false;
break;
}
debug(LOG_DEBUG, DEBUG_LOG, 0, "nonuniqueness of solution of a "
"partial differential equation");
// start building up the union of things to be restricted to a box
Nef_nary_union unioner;
// create a the solution surface
try {
if (show_solution) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding solution surface");
unioner.add_polyhedron(build_solution(sheetthickness));
debug(LOG_DEBUG, DEBUG_LOG, 0, "solution surface added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add solution: %s",
x.what());
}
// create an alternative solution surface
try {
if (show_alternatives) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding alternatives");
unioner.add_polyhedron(build_alternative(sheetthickness));
debug(LOG_DEBUG, DEBUG_LOG, 0, "alternatives added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add alternatives: %s",
x.what());
}
// add additional characteristics
try {
if (show_characteristics) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding characteristics");
unioner.add_polyhedron(build_characteristics());
debug(LOG_DEBUG, DEBUG_LOG, 0, "characteristics added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add characteristics: %s",
x.what());
}
// add negative characteristics
try {
if (show_negative) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding neg characteristics");
unioner.add_polyhedron(build_xcharacteristics());
debug(LOG_DEBUG, DEBUG_LOG, 0, "neg characteristics added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add negative characteristics: %s",
x.what());
}
// add the FCurve
try {
if (show_fcurve) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding fcurve");
unioner.add_polyhedron(build_fcurve());
debug(LOG_DEBUG, DEBUG_LOG, 0, "fcurve added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add fcurve: %s",
x.what());
}
// add the support sheet
try {
if (show_support) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding support");
unioner.add_polyhedron(build_support(sheetthickness));
debug(LOG_DEBUG, DEBUG_LOG, 0, "support added");
}
} catch (std::exception& x) {
debug(LOG_ERR, DEBUG_LOG, 0, "failed to add support: %s",
x.what());
}
// add the initial curve
if (show_initial) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding initial curve");
unioner.add_polyhedron(build_initialcurve());
debug(LOG_DEBUG, DEBUG_LOG, 0, "initial curve added");
}
// extract union
debug(LOG_DEBUG, DEBUG_LOG, 0, "extract the image component union");
Nef_polyhedron image = unioner.get_union();
debug(LOG_DEBUG, DEBUG_LOG, 0, "base image constructed");
// restrict everything to a box
debug(LOG_DEBUG, DEBUG_LOG, 0, "restrict to a box");
Build_Box box(point(-0.1, -2, -2), point(4, 2, 2));
Polyhedron boxp;
boxp.delegate(box);
image = image * boxp;
debug(LOG_DEBUG, DEBUG_LOG, 0, "restriction complete");
// add axes
if (show_axes) {
debug(LOG_DEBUG, DEBUG_LOG, 0, "adding axes");
image = image + build_axes();
debug(LOG_DEBUG, DEBUG_LOG, 0, "axes added");
}
// output
Polyhedron P;
debug(LOG_DEBUG, DEBUG_LOG, 0, "convert to polyhedron for output");
image.convert_to_polyhedron(P);
std::cout << P;
// write parts
if (prefix.size() > 0) {
PartWriter pw(prefix);
pw(PartWriter::LEFT_PART, image);
pw(PartWriter::RIGHT_PART, image);
pw(PartWriter::FRONT_PART, image);
pw(PartWriter::BACK_PART, image);
} else {
debug(LOG_DEBUG, DEBUG_LOG, 0, "part output suppressed");
}
// that's it
debug(LOG_DEBUG, DEBUG_LOG, 0, "output complete");
return EXIT_SUCCESS;
}
