介绍：点云贪心三角化
输入pcd文件，输出vtk文件。
主要就是一下两个参数：

设置用于确定用于三角测量的最近邻的球面半径
gpt.setSearchRadius (radius);

设置最近邻距离的乘法器，得到每个点的最终搜索半径(这将使算法适应云中不同的点密度)。
gpt.setMu (mu);

代码如下：

#include <pcl/io/pcd_io.h>
#include <pcl/io/vtk_io.h>
#include <pcl/console/print.h>
#include <pcl/console/parse.h>
#include <pcl/console/time.h>
#include <pcl/surface/gp3.h>

using namespace pcl;
using namespace pcl::io;
using namespace pcl::console;

double default_mu = 0.0;
double default_radius = 0.0;

void
printHelp (int, char **argv)
{
  print_error ("Syntax is: %s input.pcd output.vtk <options>\n", argv[0]);
  print_info ("  where options are:\n");
  print_info ("                     -radius X = use a radius of Xm around each point to determine the neighborhood (default: "); 
  print_value ("%f", default_radius); print_info (")\n");
  print_info ("                     -mu X     = set the multipler of the nearest neighbor distance to obtain the final search radius (default: "); 
  print_value ("%f", default_mu); print_info (")\n");
}

bool
loadCloud (const std::string &filename, PointCloud<PointNormal> &cloud)
{
  TicToc tt;
  print_highlight ("Loading "); print_value ("%s ", filename.c_str ());

  tt.tic ();
  if (loadPCDFile<PointNormal> (filename, cloud) < 0)
    return (false);
  print_info ("[done, "); print_value ("%g", tt.toc ()); print_info (" ms : "); print_value ("%d", cloud.width * cloud.height); print_info (" points]\n");
  print_info ("Available dimensions: "); print_value ("%s\n", pcl::getFieldsList (cloud).c_str ());

  return (true);
}

void
compute (const PointCloud<PointNormal>::Ptr &input, pcl::PolygonMesh &output,
         double mu, double radius)
{
  // Estimate
  TicToc tt;
  tt.tic ();
  
  print_highlight (stderr, "Computing ");

  PointCloud<PointNormal>::Ptr cloud (new PointCloud<PointNormal> ());
  for (size_t i = 0; i < input->size (); ++i)
    if (pcl_isfinite (input->points[i].x))
      cloud->push_back (input->points[i]);

  cloud->width = static_cast<uint32_t> (cloud->size ());
  cloud->height = 1;
  cloud->is_dense = true;

  GreedyProjectionTriangulation<PointNormal> gpt;
  gpt.setSearchMethod (pcl::search::KdTree<pcl::PointNormal>::Ptr (new pcl::search::KdTree<pcl::PointNormal>));
  gpt.setInputCloud (cloud);
  gpt.setSearchRadius (radius);
  gpt.setMu (mu);

  gpt.reconstruct (output);

  print_info ("[done, "); print_value ("%g", tt.toc ()); print_info (" ms : "); print_value ("%lu", output.polygons.size ()); print_info (" polygons]\n");
}

void
saveCloud (const std::string &filename, const pcl::PolygonMesh &output)
{
  TicToc tt;
  tt.tic ();

  print_highlight ("Saving "); print_value ("%s ", filename.c_str ());
  saveVTKFile (filename, output);

  print_info ("[done, "); print_value ("%g", tt.toc ()); print_info (" ms : "); print_value ("%lu", output.polygons.size ()); print_info (" polygons]\n");
}

/* ---[ */
int
main (int argc, char** argv)
{
  print_info ("Perform surface triangulation using pcl::GreedyProjectionTriangulation. For more information, use: %s -h\n", argv[0]);

  if (argc < 3)
  {
    printHelp (argc, argv);
    return (-1);
  }

  // Parse the command line arguments for .pcd files
  std::vector<int> pcd_file_indices = parse_file_extension_argument (argc, argv, ".pcd");
  if (pcd_file_indices.size () != 1)
  {
    print_error ("Need one input PCD file to continue.\n");
    return (-1);
  }
  std::vector<int> vtk_file_indices = parse_file_extension_argument (argc, argv, ".vtk");
  if (vtk_file_indices.size () != 1)
  {
    print_error ("Need one output VTK file to continue.\n");
    return (-1);
  }

  // Command line parsing
  double mu = default_mu;
  double radius = default_radius;
  parse_argument (argc, argv, "-mu", mu);
  parse_argument (argc, argv, "-radius", radius);

  // Load the first file
  PointCloud<PointNormal>::Ptr cloud (new PointCloud<PointNormal>);
  if (!loadCloud (argv[pcd_file_indices[0]], *cloud)) 
    return (-1);

  // Perform the surface triangulation
  pcl::PolygonMesh output;
  compute (cloud, output, mu, radius);

  // Save into the second file
  saveCloud (argv[vtk_file_indices[0]], output);
}

来源：PCL官方示例