\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.11.3 - Point Set Processing
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Point_set_processing_3/grid_simplify_indices.cpp
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/grid_simplify_point_set.h>
#include <CGAL/IO/read_xyz_points.h>
#include <CGAL/property_map.h>
#include <vector>
#include <fstream>
// types
typedef Kernel::Point_3 Point;
typedef Kernel::Vector_3 Vector;
int main(int argc, char*argv[])
{
// Reads a .xyz point set file in points[].
std::vector<Point> points;
std::vector<Vector> normals;
const char* fname = (argc>1)?argv[1]:"data/fin90_with_PCA_normals.xyz";
std::ifstream stream(fname);
Point p;
Vector v;
while(stream >> p >> v){
points.push_back(p);
normals.push_back(v);
}
std::cout << points.size() << " input points" << std::endl;
std::vector<std::size_t> indices(points.size());
for(std::size_t i = 0; i < points.size(); ++i){
indices[i] = i;
}
// simplification by clustering using erase-remove idiom
double cell_size = 0.05;
std::vector<std::size_t>::iterator end;
end = CGAL::grid_simplify_point_set(indices.begin(),
indices.end(),
cell_size);
std::size_t k = end - indices.begin();
std::cerr << "Keep " << k << " of " << indices.size() << "indices" << std::endl;
{
std::vector<Point> tmp_points(k);
std::vector<Vector> tmp_normals(k);
for(std::size_t i=0; i<k; ++i){
tmp_points[i] = points[indices[i]];
tmp_normals[i] = normals[indices[i]];
}
points.swap(tmp_points);
normals.swap(tmp_normals);
}
std::cout << points.size() << " points after the simplification" << std::endl;
return EXIT_SUCCESS;
}