CGAL中的一副点云带有颜色属性当这副点云插入另一幅没有颜色属性 的点云中如何保留其中带有颜色属性的部分。请附上代码

以下是一个示例代码，演示如何将带有颜色属性的点云插入到没有颜色属性的点云中，并保留颜色属性。

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/property_map.h>
#include <CGAL/IO/read_xyz_points.h>
#include <CGAL/Polygon_mesh_processing/measure.h>
#include <CGAL/Polygon_mesh_processing/repair.h>
#include <CGAL/Polygon_mesh_processing/polygon_soup_to_polygon_mesh.h>
#include <CGAL/Polygon_mesh_processing/triangulate_faces.h>
#include <CGAL/Polygon_mesh_processing/clip.h>
#include <CGAL/Surface_mesh.h>
#include <CGAL/IO/write_xyz_points.h>
#include <CGAL/IO/write_off_points.h>
#include <CGAL/IO/write_ply_points.h>
#include <CGAL/IO/write_ply.h>
#include <CGAL/IO/write_obj.h>
#include <CGAL/IO/write_stl.h>
#include <CGAL/IO/read_off_points.h>
#include <CGAL/IO/read_ply_points.h>
#include <CGAL/IO/read_ply.h>
#include <CGAL/IO/read_obj.h>
#include <CGAL/IO/read_stl.h>
#include <CGAL/IO/write_wavefront.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
#include <CGAL/boost/graph/convert_polyhedron_to_polygon_mesh.h>

#include <iostream>
#include <fstream>

typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;
typedef Kernel::Point_3 Point;
typedef Kernel::Vector_3 Vector;
typedef CGAL::Surface_mesh<Point> Mesh;

int main()
{
  // Read the mesh with color property
  Mesh mesh;
  std::ifstream input("mesh_with_color.ply");
  if (!input || !(input >> mesh) || !CGAL::is_triangle_mesh(mesh)) {
    std::cerr << "Invalid or non-existing input file." << std::endl;
    return EXIT_FAILURE;
  }

  // Extract the color property map
  typedef boost::property_map<Mesh, CGAL::vertex_point_t>::type PointMap;
  typedef boost::property_map<Mesh, CGAL::vertex_color_t>::type ColorMap;
  PointMap point_map = get(CGAL::vertex_point, mesh);
  ColorMap color_map = get(CGAL::vertex_color, mesh);

  // Read the mesh without color property
  Mesh mesh2;
  std::ifstream input2("mesh_without_color.ply");
  if (!input2 || !(input2 >> mesh2) || !CGAL::is_triangle_mesh(mesh2)) {
    std::cerr << "Invalid or non-existing input file." << std::endl;
    return EXIT_FAILURE;
  }

  // Insert the colored vertices into the mesh without color property
  int vertex_offset = mesh2.number_of_vertices();
  Mesh::Vertex_index_map index_map;
  boost::associative_property_map<Mesh::Vertex_index_map> index_pmap(index_map);
  Mesh::Vertex_iterator v_it, v_end = mesh.vertices_end();
  for (v_it = mesh.vertices_begin(); v_it != v_end; ++v_it) {
    Mesh::Vertex_handle vh = mesh2.add_vertex(point_map[*v_it]);
    color_map[vh] = color_map[*v_it];
    index_map[vh] = vertex_offset++;
  }

  // Insert the faces into the mesh without color property
  Mesh::Face_iterator f_it, f_end = mesh.faces_end();
  for (f_it = mesh.faces_begin(); f_it != f_end; ++f_it) {
    Mesh::Vertex_index v0 = index_map[mesh.vertex(f_it, 0)];
    Mesh::Vertex_index v1 = index_map[mesh.vertex(f_it, 1)];
    Mesh::Vertex_index v2 = index_map[mesh.vertex(f_it, 2)];
    mesh2.add_face(v0, v1, v2);
  }

  // Write the resulting mesh with color property
  std::ofstream output("resulting_mesh.ply");
  output << mesh2;

  return EXIT_SUCCESS;
}

该示例代码假设存在两个点云文件，一个带有颜色属性，一个没有颜色属性。首先，读取带有颜色属性的点云，并提取出颜色属性映射。接着，读取没有颜色属性的点云，并将带有颜色属性的点云中的每个顶点插入到没有颜色属性的点云中。在插入过程中，将颜色属性从带有颜色属性的点云中复制到没有颜色属性的点云中。最后，将结果点云写入文件中