\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.13.2 - Planar Parameterization of Triangulated Surface Meshes
Surface_mesh_parameterization/square_border_parameterizer.cpp
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/Surface_mesh_parameterization/IO/File_off.h>
#include <CGAL/Surface_mesh_parameterization/Square_border_parameterizer_3.h>
#include <CGAL/Surface_mesh_parameterization/Discrete_conformal_map_parameterizer_3.h>
#include <CGAL/Surface_mesh_parameterization/parameterize.h>
#include <CGAL/Polygon_mesh_processing/measure.h>
#include <CGAL/Unique_hash_map.h>
#include <boost/array.hpp>
#include <boost/foreach.hpp>
#include <boost/unordered_set.hpp>
#include <cstdlib>
#include <iostream>
#include <fstream>
typedef Kernel::Point_2 Point_2;
typedef Kernel::Point_3 Point_3;
typedef CGAL::Polyhedron_3<Kernel> PolyMesh;
typedef boost::graph_traits<PolyMesh>::halfedge_descriptor halfedge_descriptor;
typedef boost::graph_traits<PolyMesh>::vertex_descriptor vertex_descriptor;
typedef boost::graph_traits<PolyMesh>::face_descriptor face_descriptor;
typedef boost::graph_traits<PolyMesh>::vertex_iterator vertex_iterator;
typedef boost::array<vertex_descriptor, 4> Vd_array;
typedef boost::associative_property_map<UV_uhm> UV_pmap;
bool read_vertices(const PolyMesh& mesh,
const char* filename,
Vd_array& fixed_vertices)
{
std::string str = filename;
if( (str.length()) < 14 || (str.substr(str.length() - 14) != ".selection.txt") ) {
std::cerr << "Error: vertices must be given by a *.selection.txt file" << std::endl;
return false;
}
std::ifstream in(filename);
std::string line;
if(!std::getline(in, line)) {
std::cerr << "Error: could not read input file: " << filename << std::endl;
return false;
}
// The selection file is a list of integers, so we must build a correspondence
// between vertices and the integers.
std::vector<vertex_descriptor> vds;
vds.reserve(num_vertices(mesh));
vertex_iterator vi = vertices(mesh).begin(), vi_end = vertices(mesh).end();
CGAL_For_all(vi, vi_end) {
vds.push_back(*vi);
}
// Get the first line and read the fixed vertex indices
std::size_t counter = 0;
std::istringstream point_line(line);
std::size_t s;
boost::unordered_set<std::size_t> indices;
while(point_line >> s) {
if(s >= vds.size())
{
std::cerr << "Error: Vertex index too large" << std::endl;
return false;
}
vertex_descriptor vd = vds[s];
if(!is_border(vd, mesh)) { // must be on the border
std::cerr << "Error: vertex is not on the border of the mesh" << std::endl;
return false;
}
if(counter >= 4) { // too many border vertices
std::cerr << "Error: Too many vertices are fixed" << std::endl;
return false;
}
fixed_vertices[counter++] = vd;
indices.insert(s);
}
if(indices.size() < 4) {
std::cerr << "Error: at least four unique vertices must be provided" << std::endl;
return false;
}
return true;
}
int main(int argc, char** argv)
{
std::ifstream in((argc>1) ? argv[1] : "data/nefertiti.off");
if(!in){
std::cerr << "Error: problem loading the input data" << std::endl;
return 1;
}
PolyMesh sm;
in >> sm;
halfedge_descriptor bhd = CGAL::Polygon_mesh_processing::longest_border(sm).first;
// The 2D points of the uv parametrisation will be written into this map
UV_uhm uv_uhm;
UV_pmap uv_map(uv_uhm);
const char* filename = (argc > 2) ? argv[2] : "data/square_corners.selection.txt";
Vd_array vda;
if(!read_vertices(sm, filename, vda)) {
std::cerr << "Error: problem loading the square corners" << std::endl;
return EXIT_FAILURE;
}
typedef SMP::Square_border_uniform_parameterizer_3<PolyMesh> Border_parameterizer;
typedef SMP::Discrete_conformal_map_parameterizer_3<PolyMesh, Border_parameterizer> Parameterizer;
// Border parameterizers (pick one)
Border_parameterizer border_param(vda[0], vda[1], vda[2], vda[3]);
// Border_parameterizer border_param; // the border parameterizer will compute the corner vertices
SMP::Error_code err = SMP::parameterize(sm, Parameterizer(border_param), bhd, uv_map);
if(err != SMP::OK) {
std::cerr << "Error: " << SMP::get_error_message(err) << std::endl;
return 1;
}
std::ofstream out("result.off");
SMP::IO::output_uvmap_to_off(sm, bhd, uv_map, out);
return EXIT_SUCCESS;
}