CGAL 5.4.1 - Shape Detection
Shape_detection/region_growing_circles_on_point_set_2.cpp
#include <CGAL/Real_timer.h>
#include <CGAL/Random.h>
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Point_set_3.h>
#include <CGAL/Point_set_3/IO.h>
#include <CGAL/Shape_detection/Region_growing/Region_growing.h>
#include <CGAL/Shape_detection/Region_growing/Region_growing_on_point_set.h>
#include <boost/iterator/function_output_iterator.hpp>
#include <fstream>
using Point_3 = Kernel::Point_3;
using Vector_3 = Kernel::Vector_3;
using Point_2 = Kernel::Point_2;
using Vector_2 = Kernel::Vector_2;
using Point_map = Point_set_2::Point_map;
using Normal_map = Point_set_2::Vector_map;
namespace Shape_detection = CGAL::Shape_detection::Point_set;
using Neighbor_query = Shape_detection::K_neighbor_query
<Kernel, Point_set_2, Point_map>;
using Region_type = Shape_detection::Least_squares_circle_fit_region
<Kernel, Point_set_2, Point_map, Normal_map>;
using Sorting = Shape_detection::Least_squares_circle_fit_sorting
<Kernel, Point_set_2, Neighbor_query, Point_map>;
<Point_set_2, Neighbor_query, Region_type, typename Sorting::Seed_map>;
int main (int argc, char** argv)
{
std::ifstream ifile (argc > 1 ? argv[1] : CGAL::data_file_path("points_3/circles.ply"));
Point_set_3 points3;
ifile >> points3;
std::cerr << points3.size() << " points read" << std::endl;
// Input should have normals
assert (points3.has_normal_map());
Point_set_2 points;
points.add_normal_map();
for (Point_set_3::Index idx : points3)
{
const Point_3& p = points3.point(idx);
const Vector_3& n = points3.normal(idx);
points.insert (Point_2 (p.x(), p.y()), Vector_2 (n.x(), n.y()));
}
// Default parameters for data/circles.ply
const std::size_t k = 12;
const double tolerance = 0.01;
const double max_angle = 10.;
const std::size_t min_region_size = 20;
// No constraint on radius
const double min_radius = 0.;
const double max_radius = std::numeric_limits<double>::infinity();
Neighbor_query neighbor_query(points, k, points.point_map());
Region_type region_type(points, tolerance, max_angle, min_region_size,
min_radius, max_radius,
points.point_map(), points.normal_map());
// Sort indices
Sorting sorting(points, neighbor_query, points.point_map());
sorting.sort();
Region_growing region_growing(points, neighbor_query, region_type, sorting.seed_map());
// Add maps to get colored output
Point_set_3::Property_map<unsigned char>
red = points3.add_property_map<unsigned char>("red", 0).first,
green = points3.add_property_map<unsigned char>("green", 0).first,
blue = points3.add_property_map<unsigned char>("blue", 0).first;
CGAL::Random random;
std::size_t nb_circles = 0;
CGAL::Real_timer timer;
timer.start();
region_growing.detect
(boost::make_function_output_iterator
([&](const std::vector<std::size_t>& region)
{
// Assign a random color to each region
unsigned char r = static_cast<unsigned char>(random.get_int(64, 192));
unsigned char g = static_cast<unsigned char>(random.get_int(64, 192));
unsigned char b = static_cast<unsigned char>(random.get_int(64, 192));
for (const std::size_t& idx : region)
{
red[idx] = r;
green[idx] = g;
blue[idx] = b;
}
++ nb_circles;
}));
timer.stop();
std::cerr << nb_circles << " circles detected in "
<< timer.time() << " seconds" << std::endl;
// Save in colored_circles.ply
std::ofstream out ("colored_circles.ply");
out << points3;
return EXIT_SUCCESS;
}