我正在尝试修改CGAL-4.13/examples/Surface_mesh_parameterization/lscm.cpp，以便生成的关闭文件中的顶点顺序与输入文件中的相同。
更新：示例
获取input.off具有以下简单内容的文件：
OFF
4 2 0
-0.9310345 0.4333333 0
-1 0.4333333 0
-0.9310345 0.5 0
-1 0.5 0
3 1 0 2
3 2 3 1
当我用lscmCGAL 调用标准时
/path/to/CGAL-4.13-build/examples/Surface_mesh_parameterization/lscm input.off
我得到coords.off包含
OFF
4 2 0
-1 0.5 0
-0.931034 0.5 0
-0.931034 0.433333 0
-1 0.433333 0
3 3 2 1
3 1 0 3
并uvmap.off与
OFF
4 2 0
-0.0166567 0.982769 0
1 1 0
1.01666 0.0172311 0
0 0 0
3 3 2 1
3 1 0 3
文件coords.off和uvmap.off包含相同顺序的顶点及其参数对（与 中的不同）input.off。相反，我希望参数uvmap.off的顺序对应于input.off. 特别是，我想uvmap.off看起来像这样：
OFF
4 2 0
1.01666 0.0172311 0
0 0 0
1 1 0
-0.0166567 0.982769 0
3 1 0 2
3 2 3 1
基本上，这会coords.off变得多余，因为我可以input.off在它的角色中使用。
努力解决
据我了解，这可以通过output_uvmap_to_off(...)使用 6 个参数而不是 4 个参数调用来实现（两个版本都可以在 中找到CGAL-4.13/include/CGAL/Surface_mesh_parameterization/IO/File_off.h）。由于这些参数之一是 a VertexIndexMap，我可能也应该使用
CGAL::Surface_mesh_parameterization::LSCM_parameterizer_3< TriangleMesh_, BorderParameterizer_, SolverTraits_ >::parameterize(...)
代替
CGAL::Surface_mesh_parameterization::parameterize(...)
示例中使用。
这是一个最小的（不是真正有效的）示例。它源自lscm.cpp但我扔掉了很多东西以保持简洁。
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/boost/graph/Seam_mesh.h>
#include <CGAL/Surface_mesh_parameterization/IO/File_off.h>
#include <CGAL/Surface_mesh_parameterization/parameterize.h>
#include <CGAL/Surface_mesh_parameterization/Two_vertices_parameterizer_3.h>
#include <CGAL/Surface_mesh_parameterization/LSCM_parameterizer_3.h>
#include <CGAL/Polygon_mesh_processing/measure.h>
#include <boost/foreach.hpp>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
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>::edge_descriptor SM_edge_descriptor;
typedef boost::graph_traits<SurfaceMesh>::halfedge_descriptor SM_halfedge_descriptor;
typedef boost::graph_traits<SurfaceMesh>::vertex_descriptor SM_vertex_descriptor;
typedef SurfaceMesh::Property_map<SM_halfedge_descriptor, Point_2> UV_pmap;
typedef SurfaceMesh::Property_map<SM_edge_descriptor, bool> Seam_edge_pmap;
typedef SurfaceMesh::Property_map<SM_vertex_descriptor, bool> Seam_vertex_pmap;
typedef CGAL::Seam_mesh<SurfaceMesh, Seam_edge_pmap, Seam_vertex_pmap> Mesh;
typedef boost::graph_traits<Mesh>::vertex_descriptor vertex_descriptor;
typedef boost::graph_traits<Mesh>::halfedge_descriptor halfedge_descriptor;
typedef boost::graph_traits<Mesh>::face_descriptor face_descriptor;
namespace SMP = CGAL::Surface_mesh_parameterization;
int main(int argc, char** argv)
{
std::ifstream in_mesh((argc>1) ? argv[1] : "data/lion.off");
if(!in_mesh){
std::cerr << "Error: problem loading the input data" << std::endl;
return EXIT_FAILURE;
}
SurfaceMesh sm;
in_mesh >> sm;
Seam_edge_pmap seam_edge_pm = sm.add_property_map<SM_edge_descriptor, bool>("e:on_seam", false).first;
Seam_vertex_pmap seam_vertex_pm = sm.add_property_map<SM_vertex_descriptor, bool>("v:on_seam", false).first;
Mesh mesh(sm, seam_edge_pm, seam_vertex_pm);
UV_pmap uv_pm = sm.add_property_map<SM_halfedge_descriptor, Point_2>("h:uv").first;
halfedge_descriptor bhd = CGAL::Polygon_mesh_processing::longest_border(mesh, CGAL::Polygon_mesh_processing::parameters::all_default()).first;
typedef SMP::Two_vertices_parameterizer_3<Mesh> Border_parameterizer;
typedef SMP::LSCM_parameterizer_3<Mesh, Border_parameterizer> Parameterizer;
// Here's where the big changes start.
SurfaceMesh::Property_map<SM_halfedge_descriptor, int> vimap = sm.add_property_map<SM_halfedge_descriptor, int>("h:vi").first;
SurfaceMesh::Property_map<SM_halfedge_descriptor, bool> vpmap = sm.add_property_map<SM_halfedge_descriptor, bool>("h:vp").first;
Parameterizer parameterizer;
parameterizer.parameterize(mesh, bhd, uv_pm, vimap, vpmap);
const char* uvmap_file = "uvmap.off";
std::ofstream uvmap_out(uvmap_file);
SMP::IO::output_uvmap_to_off(mesh,sm.vertices(),sm.faces(),uv_pm,vimap,uvmap_out);
return EXIT_SUCCESS;
}
这不会编译，抱怨 File_off.h 的第 131 行需要转换。