通过projectPoint将点投影到平面上，代码如下：

#include <pcl/PCLPointCloud2.h>
#include <pcl/io/pcd_io.h>
#include <pcl/features/normal_3d.h>
#include <pcl/console/print.h>
#include <pcl/console/parse.h>
#include <pcl/console/time.h>
#include <pcl/sample_consensus/sac_model_plane.h>using namespace pcl;
using namespace pcl::io;
using namespace pcl::console;Eigen::Vector4f    translation;
Eigen::Quaternionf orientation;void
printHelp (int, char **argv)
{print_error ("Syntax is: %s input.pcd output.pcd A B C D\n", argv[0]);print_info ("  where the plane is represented by the following equation:\n");print_info ("                     Ax + By + Cz + D = 0\n"); 
}bool
loadCloud (const std::string &filename, pcl::PCLPointCloud2 &cloud)
{TicToc tt;print_highlight ("Loading "); print_value ("%s ", filename.c_str ());tt.tic ();if (loadPCDFile (filename, cloud, translation, orientation) < 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
project (const pcl::PCLPointCloud2::ConstPtr &input, pcl::PCLPointCloud2 &output, float a, float b, float c, float d)
{Eigen::Vector4f coeffs;coeffs << a, b, c, d;// Convert data to PointCloud<T>PointCloud<PointXYZ>::Ptr xyz (new PointCloud<PointXYZ>);fromPCLPointCloud2 (*input, *xyz);// EstimateTicToc tt;tt.tic ();//First, we'll find a point on the planeprint_highlight (stderr, "Projecting ");PointCloud<PointXYZ>::Ptr projected_cloud_pcl (new PointCloud<PointXYZ>);projected_cloud_pcl->width = xyz->width;projected_cloud_pcl->height = xyz->height;projected_cloud_pcl->is_dense = xyz->is_dense;projected_cloud_pcl->sensor_origin_ = xyz->sensor_origin_;projected_cloud_pcl->sensor_orientation_ = xyz->sensor_orientation_;for(size_t i = 0; i < xyz->points.size(); ++i){pcl::PointXYZ projection;pcl::projectPoint<PointXYZ> (xyz->points[i], coeffs, projection);projected_cloud_pcl->points.push_back(projection);}print_info ("[done, "); print_value ("%g", tt.toc ()); print_info (" ms : ");pcl::io::savePCDFile ("foo.pcd", *projected_cloud_pcl);// Convert data backpcl::PCLPointCloud2 projected_cloud;toPCLPointCloud2 (*projected_cloud_pcl, projected_cloud);//we can actually use concatenate fields to inject our projection into the//output, the second argument overwrites the first's fields for those that//are sharedconcatenateFields (*input, projected_cloud, output);
}void
saveCloud (const std::string &filename, const pcl::PCLPointCloud2 &output)
{TicToc tt;tt.tic ();print_highlight ("Saving "); print_value ("%s ", filename.c_str ());pcl::io::savePCDFile (filename, output, translation, orientation, false);print_info ("[done, "); print_value ("%g", tt.toc ()); print_info (" ms : "); print_value ("%d", output.width * output.height); print_info (" points]\n");
}/* ---[ */
int
main (int argc, char** argv)
{print_info ("Estimate surface normals using pcl::NormalEstimation. For more information, use: %s -h\n", argv[0]);if (argc < 3){printHelp (argc, argv);return (-1);}// Parse the command line arguments for .pcd filesstd::vector<int> p_file_indices;p_file_indices = parse_file_extension_argument (argc, argv, ".pcd");if (p_file_indices.size () != 2){print_error ("Need one input PCD file and one output PCD file to continue.\n");return (-1);}if(argc != 7){print_error("This function takes: input_file output_file A B C D");return(-1);}// Command line parsingfloat a = static_cast<float> (atof (argv[3]));float b = static_cast<float> (atof (argv[4]));float c = static_cast<float> (atof (argv[5]));float d = static_cast<float> (atof (argv[6]));// Load the first filepcl::PCLPointCloud2::Ptr cloud (new pcl::PCLPointCloud2);if (!loadCloud (argv[p_file_indices[0]], *cloud)) return (-1);// Perform the feature estimationpcl::PCLPointCloud2 output;project (cloud, output, a, b, c, d);// Save into the second filesaveCloud (argv[p_file_indices[1]], output);
}

来源：PCL官方示例