CGAL 5.6.1 - Point Set Processing
Point_set_processing_3/scale_estimation_example.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/IO/read_points.h>
#include <CGAL/estimate_scale.h>
#include <CGAL/jet_smooth_point_set.h>
#include <CGAL/grid_simplify_point_set.h>
#include <CGAL/Timer.h>
#include <CGAL/Memory_sizer.h>
#include <vector>
#include <fstream>
// Concurrency
typedef CGAL::Parallel_if_available_tag Concurrency_tag;
// Types
typedef Kernel::FT FT;
typedef Kernel::Point_3 Point_3;
int main (int argc, char** argv)
{
const std::string fname = (argc>1)?argv[1]:CGAL::data_file_path("points_3/sphere_20k.xyz");
CGAL::Timer task_timer;
// read input
std::vector<Point_3> points;
if(!CGAL::IO::read_points(fname, std::back_inserter(points)))
{
std::cerr << "Error: can't read input file" << std::endl;
return EXIT_FAILURE;
}
// estimate k scale
task_timer.start();
std::size_t k_scale = CGAL::estimate_global_k_neighbor_scale (points);
task_timer.stop();
// Example: use estimated k as scale for jet smoothing
CGAL::jet_smooth_point_set<Concurrency_tag>(points, static_cast<unsigned int>(k_scale));
// estimate range scale
task_timer.start();
FT range_scale = CGAL::estimate_global_range_scale (points);
task_timer.stop();
// Example: use estimated range for grid simplification
points.erase(CGAL::grid_simplify_point_set(points, range_scale), points.end());
// print some information on runtime
std::size_t memory = CGAL::Memory_sizer().virtual_size();
double time = task_timer.time();
std::cout << "Scales computed in " << time << " second(s) using "
<< (memory>>20) << " MiB of memory:" << std::endl;
std::cout << " * Global K scale: " << k_scale << std::endl;
std::cout << " * Global range scale: " << range_scale << std::endl;
return EXIT_SUCCESS;
}