CGAL 5.1.3 - Shape Detection
Shape_detection/region_growing_on_point_set_3.cpp
// STL includes.
#include <string>
#include <vector>
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <iterator>
// Boost includes.
#include <boost/iterator/function_output_iterator.hpp>
// CGAL includes.
#include <CGAL/Timer.h>
#include <CGAL/Random.h>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.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>
// Type declarations.
using FT = typename Kernel::FT;
using Point_3 = typename Kernel::Point_3;
using Vector_3 = typename Kernel::Vector_3;
using Input_range = CGAL::Point_set_3<Point_3>;
using Point_map = typename Input_range::Point_map;
using Normal_map = typename Input_range::Vector_map;
using Indices = std::vector<std::size_t>;
using Output_range = CGAL::Point_set_3<Point_3>;
using Points_3 = std::vector<Point_3>;
// Define an insert iterator.
struct Insert_point_colored_by_region_index {
using argument_type = Indices;
using result_type = void;
using Color_map =
typename Output_range:: template Property_map<unsigned char>;
const Input_range& m_input_range;
const Point_map m_point_map;
Output_range& m_output_range;
std::size_t& m_number_of_regions;
Color_map m_red, m_green, m_blue;
Insert_point_colored_by_region_index(
const Input_range& input_range,
const Point_map point_map,
Output_range& output_range,
std::size_t& number_of_regions) :
m_input_range(input_range),
m_point_map(point_map),
m_output_range(output_range),
m_number_of_regions(number_of_regions) {
m_red =
m_output_range.template add_property_map<unsigned char>("red", 0).first;
m_green =
m_output_range.template add_property_map<unsigned char>("green", 0).first;
m_blue =
m_output_range.template add_property_map<unsigned char>("blue", 0).first;
}
result_type operator()(const argument_type& region) {
CGAL::Random rand(static_cast<unsigned int>(m_number_of_regions));
const unsigned char r =
static_cast<unsigned char>(64 + rand.get_int(0, 192));
const unsigned char g =
static_cast<unsigned char>(64 + rand.get_int(0, 192));
const unsigned char b =
static_cast<unsigned char>(64 + rand.get_int(0, 192));
for (const std::size_t index : region) {
const auto& key = *(m_input_range.begin() + index);
const Point_3& point = get(m_point_map, key);
const auto it = m_output_range.insert(point);
m_red[*it] = r;
m_green[*it] = g;
m_blue[*it] = b;
}
++m_number_of_regions;
}
}; // Insert_point_colored_by_region_index
int main(int argc, char *argv[]) {
std::cout << std::endl <<
"region_growing_on_point_set_3 example started"
<< std::endl << std::endl;
std::cout <<
"Note: if 0 points are loaded, please specify the path to the file data/point_set_3.xyz by hand!"
<< std::endl << std::endl;
// Load xyz data either from a local folder or a user-provided file.
std::ifstream in(argc > 1 ? argv[1] : "data/point_set_3.xyz");
if (!in) {
std::cout <<
"Error: cannot read the file point_set_3.xyz!" << std::endl;
std::cout <<
"You can either create a symlink to the data folder or provide this file by hand."
<< std::endl << std::endl;
return EXIT_FAILURE;
}
const bool with_normal_map = true;
Input_range input_range(with_normal_map);
in >> input_range;
in.close();
std::cout <<
"* loaded "
<< input_range.size() <<
" points with normals"
<< std::endl;
// Default parameter values for the data file point_set_3.xyz.
const std::size_t k = 12;
const FT max_distance_to_plane = FT(2);
const FT max_accepted_angle = FT(20);
const std::size_t min_region_size = 50;
// Create instances of the classes Neighbor_query and Region_type.
Neighbor_query neighbor_query(
input_range,
k,
input_range.point_map());
Region_type region_type(
input_range,
max_distance_to_plane, max_accepted_angle, min_region_size,
input_range.point_map(), input_range.normal_map());
// Create an instance of the region growing class.
Region_growing region_growing(
input_range, neighbor_query, region_type);
// Run the algorithm.
Output_range output_range;
std::size_t number_of_regions = 0;
Insert_point_colored_by_region_index inserter(
input_range, input_range.point_map(),
output_range, number_of_regions);
CGAL::Timer timer;
timer.start();
region_growing.detect(
boost::make_function_output_iterator(inserter));
timer.stop();
// Print the number of found regions.
std::cout << "* " << number_of_regions <<
" regions have been found in " << timer.time() << " seconds"
<< std::endl;
// Save the result to a file in the user-provided path if any.
if (argc > 2) {
const std::string path = argv[2];
const std::string fullpath = path + "regions_point_set_3.ply";
std::ofstream out(fullpath);
out << output_range;
std::cout << "* found regions are saved in " << fullpath << std::endl;
out.close();
}
// Get all unassigned items.
Indices unassigned_items;
region_growing.unassigned_items(std::back_inserter(unassigned_items));
// Print the number of unassigned items.
std::cout << "* " << unassigned_items.size() <<
" points do not belong to any region"
<< std::endl;
// Store all unassigned points.
Points_3 unassigned_points;
unassigned_points.reserve(unassigned_items.size());
for (const auto index : unassigned_items) {
const auto& key = *(input_range.begin() + index);
const Point_3& point = get(input_range.point_map(), key);
unassigned_points.push_back(point);
}
std::cout << "* " << unassigned_points.size() <<
" unassigned points are stored"
<< std::endl;
std::cout << std::endl <<
"region_growing_on_point_set_3 example finished"
<< std::endl << std::endl;
return EXIT_SUCCESS;
}