1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Isosurfacing_3/Cartesian_grid_3.h>
#include <CGAL/Isosurfacing_3/Value_function_3.h>
#include <CGAL/Isosurfacing_3/marching_cubes_3.h>
#include <CGAL/Isosurfacing_3/Marching_cubes_domain_3.h>
#include <CGAL/Real_timer.h>
#include <CGAL/IO/polygon_soup_io.h>
#include <vector>
using Kernel = CGAL::Simple_cartesian<double>;
using FT = typename Kernel::FT;
using Point = typename Kernel::Point_3;
using Vector = typename Kernel::Vector_3;
using Grid = CGAL::Isosurfacing::Cartesian_grid_3<Kernel>;
using Values = CGAL::Isosurfacing::Value_function_3<Grid>;
using Domain = CGAL::Isosurfacing::Marching_cubes_domain_3<Grid, Values>;
using Point_range = std::vector<Point>;
using Polygon_range = std::vector<std::vector<std::size_t> >;
int main(int argc, char** argv)
{
const FT isovalue = (argc > 1) ? std::stod(argv[1]) : 0.8;
// create bounding box and grid
const CGAL::Bbox_3 bbox { -1., -1., -1., 1., 1., 1. };
Grid grid { bbox, CGAL::make_array<std::size_t>(30, 30, 30) };
std::cout << "Span: " << grid.span() << std::endl;
std::cout << "Cell dimensions: " << grid.spacing()[0] << " " << grid.spacing()[1] << " " << grid.spacing()[2] << std::endl;
std::cout << "Cell #: " << grid.xdim() << ", " << grid.ydim() << ", " << grid.zdim() << std::endl;
// fill up values
auto sphere_value_fn = [](const Point& p) -> FT
{
return sqrt(p.x()*p.x() + p.y()*p.y() + p.z()*p.z());
};
Values values { sphere_value_fn, grid };
Domain domain { grid, values };
// MC base version
{
Point_range points;
Polygon_range triangles;
CGAL::Real_timer timer;
timer.start();
// run marching cubes isosurfacing
std::cout << "Running Marching Cubes with isovalue = " << isovalue << std::endl;
CGAL::Isosurfacing::marching_cubes<CGAL::Parallel_if_available_tag>(domain, isovalue, points, triangles,
CGAL::parameters::use_topologically_correct_marching_cubes(false));
timer.stop();
std::cout << "Output #vertices: " << points.size() << std::endl;
std::cout << "Output #triangles: " << triangles.size() << std::endl;
std::cout << "Elapsed time: " << timer.time() << " seconds" << std::endl;
CGAL::IO::write_polygon_soup("marching_cubes.off", points, triangles);
}
// MC topologically correct version
{
Point_range points;
Polygon_range triangles;
CGAL::Real_timer timer;
timer.start();
// run marching cubes isosurfacing
std::cout << "Running Marching Cubes (TMC) with isovalue = " << isovalue << std::endl;
CGAL::Isosurfacing::marching_cubes<CGAL::Parallel_if_available_tag>(domain, isovalue, points, triangles,
CGAL::parameters::use_topologically_correct_marching_cubes(true));
timer.stop();
std::cout << "Output #vertices: " << points.size() << std::endl;
std::cout << "Output #triangles: " << triangles.size() << std::endl;
std::cout << "Elapsed time: " << timer.time() << " seconds" << std::endl;
CGAL::IO::write_polygon_soup("marching_cubes_TMC.off", points, triangles);
}
std::cout << "Done" << std::endl;
return EXIT_SUCCESS;
}
|
