CGAL参数化缩放

Question

我有以下代码，与示例匹配90％。我想通过参数化“展平” 3D模型。但是输入和输出的比例不同。

我有一个问题，我们如何才能保持相同的缩放比例。在下面的图像中，您可以找到输入和输出：

#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/Surface_mesh_parameterization/IO/File_off.h>
//#include <CGAL/Surface_mesh_parameterization/Circular_border_parameterizer_3.h>
//#include <CGAL/Surface_mesh_parameterization/Discrete_authalic_parameterizer_3.h>


//#include <CGAL/Surface_mesh_parameterization/Square_border_parameterizer_3.h>
//#include <CGAL/Surface_mesh_parameterization/Barycentric_mapping_parameterizer_3.h>

#include <CGAL/Surface_mesh_parameterization/Two_vertices_parameterizer_3.h>
#include <CGAL/Surface_mesh_parameterization/LSCM_parameterizer_3.h>

#include <CGAL/Surface_mesh_parameterization/Error_code.h>
#include <CGAL/Surface_mesh_parameterization/parameterize.h>
#include <CGAL/Polygon_mesh_processing/measure.h>
#include <cstdlib>
#include <iostream>
#include <fstream>
typedef CGAL::Simple_cartesian<double>       Kernel;
typedef Kernel::Point_2                      Point_2;
typedef Kernel::Point_3                      Point_3;
typedef CGAL::Surface_mesh<Kernel::Point_3>  SurfaceMesh;
typedef boost::graph_traits<SurfaceMesh>::halfedge_descriptor  halfedge_descriptor;
typedef boost::graph_traits<SurfaceMesh>::vertex_descriptor    vertex_descriptor;
typedef boost::graph_traits<SurfaceMesh>::face_descriptor      face_descriptor;
namespace SMP = CGAL::Surface_mesh_parameterization;
int main(int argc, char** argv)
{
    std::ifstream in((argc > 1) ? argv[1] : "C:/Users/Niels/Desktop/CGAL/flatten.off");
    if (!in) {
        std::cerr << "Problem loading the input data" << std::endl;
        return EXIT_FAILURE;
    }
    SurfaceMesh sm;
    in >> sm;
    // A halfedge on the border
    halfedge_descriptor bhd = CGAL::Polygon_mesh_processing::longest_border(sm).first;
    // The 2D points of the uv parametrisation will be written into this map
    typedef SurfaceMesh::Property_map<vertex_descriptor, Point_2>  UV_pmap;
    UV_pmap uv_map = sm.add_property_map<vertex_descriptor, Point_2>("v:uv").first;

    typedef SMP::Two_vertices_parameterizer_3<SurfaceMesh> Border_parameterizer;
    typedef SMP::LSCM_parameterizer_3<SurfaceMesh, Border_parameterizer> Parameterizer;

    SMP::Error_code err = SMP::parameterize(sm, Parameterizer(), bhd, uv_map);
    if (err != SMP::OK) {
        std::cerr << "Error: " << SMP::get_error_message(err) << std::endl;
        return EXIT_FAILURE;
    }
    std::ofstream out("result.off");
    SMP::IO::output_uvmap_to_off(sm, bhd, uv_map, out);
    return EXIT_SUCCESS;
}

Answer 1

我已经成功地使用了ARAP方法。默认的50次迭代实际上是不够的，并且会产生交叉的网格。将迭代次数提高到500次有效。

SMP::Error_code err = SMP::parameterize(
            in, 
            SMP::ARAP_parameterizer_3<geometry::Mesh, Border_parameterizer>(
                Border_parameterizer(),
                CGAL::Eigen_solver_traits<Eigen::SparseLU<CGAL::Eigen_sparse_matrix<double>::EigenType> >(),
                1000,
                500), 
            bhd, 
            uv_map);

...使用提交bec70a6d52