CGAL 5.6.1 - Shape Detection
Shape_detection/region_growing_spheres_on_point_set_3.cpp
#include <CGAL/Point_set_3.h>
#include <CGAL/Point_set_3/IO.h>
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Shape_detection/Region_growing/Region_growing.h>
#include <boost/iterator/function_output_iterator.hpp>
#include "include/utils.h"
// Typedefs.
using FT = Kernel::FT;
using Point_3 = Kernel::Point_3;
using Vector_3 = Kernel::Vector_3;
using Point_set = CGAL::Point_set_3<Point_3>;
using Point_map = typename Point_set::Point_map;
using Normal_map = typename Point_set::Vector_map;
using Neighbor_query = CGAL::Shape_detection::Point_set::K_neighbor_query_for_point_set<Point_set>;
using Region_type = CGAL::Shape_detection::Point_set::Least_squares_sphere_fit_region_for_point_set<Point_set>;
int main(int argc, char** argv) {
// Load ply data either from a local folder or a user-provided file.
const bool is_default_input = argc > 1 ? false : true;
std::ifstream in(is_default_input ? CGAL::data_file_path("points_3/spheres.ply") : argv[1]);
if (!in) {
std::cerr << "ERROR: cannot read the input file!" << std::endl;
return EXIT_FAILURE;
}
Point_set point_set;
in >> point_set;
in.close();
std::cout << "* number of input points: " << point_set.size() << std::endl;
assert(!is_default_input || point_set.size() == 5969);
assert(point_set.has_normal_map()); // input should have normals
// Default parameter values for the data file spheres.ply.
const std::size_t k = 12;
const FT max_distance = FT(1) / FT(100);
const FT max_angle = FT(10);
const std::size_t min_region_size = 50;
// Create instances of the classes Neighbor_query and Region_type.
Neighbor_query neighbor_query = CGAL::Shape_detection::Point_set::make_k_neighbor_query(
point_set, CGAL::parameters::k_neighbors(k));
Region_type region_type = CGAL::Shape_detection::Point_set::make_least_squares_sphere_fit_region(
point_set,
maximum_distance(max_distance).
maximum_angle(max_angle).
minimum_region_size(min_region_size));
// Create an instance of the region growing class.
Region_growing region_growing(
point_set, neighbor_query, region_type);
// Add maps to get a colored output.
Point_set::Property_map<unsigned char>
red = point_set.add_property_map<unsigned char>("red" , 0).first,
green = point_set.add_property_map<unsigned char>("green", 0).first,
blue = point_set.add_property_map<unsigned char>("blue" , 0).first;
// Run the algorithm.
std::size_t num_spheres = 0;
region_growing.detect(
boost::make_function_output_iterator(
[&](const std::pair< Region_type::Primitive, typename Region_growing::Region>& region) {
// Assign a random color to each region.
const unsigned char r = static_cast<unsigned char>(CGAL::get_default_random().get_int(64, 192));
const unsigned char g = static_cast<unsigned char>(CGAL::get_default_random().get_int(64, 192));
const unsigned char b = static_cast<unsigned char>(CGAL::get_default_random().get_int(64, 192));
for (auto item : region.second) {
red[item] = r;
green[item] = g;
blue[item] = b;
}
++num_spheres;
}
)
);
std::cout << "* number of found spheres: " << num_spheres << std::endl;
assert(!is_default_input || num_spheres == 10);
// Save regions to a file.
std::ofstream out("spheres_point_set_3.ply");
out << point_set;
return EXIT_SUCCESS;
}