（十六）点云距离图可视化

以下代码实现点云及其对应距离图的可视化。

数据样例：sphere100.pcd

range_image_visualization.cpp

#include <iostream>


#include <pcl/range_image/range_image.h>
#include <pcl/io/pcd_io.h>
#include <pcl/visualization/range_image_visualizer.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/console/parse.h>

typedef pcl::PointXYZ PointType;

// --------------------
// -----Parameters-----
// --------------------
float angular_resolution_x = 0.5f,
      angular_resolution_y = angular_resolution_x;
pcl::RangeImage::CoordinateFrame coordinate_frame = pcl::RangeImage::LASER_FRAME;
bool live_update = false;

// --------------
// -----Help-----
// --------------
void printUsage (const char* progName)
{
      std::cout << "\n\nUsage: "<<progName<<" [options] <scene.pcd>\n\n"
                  << "Options:\n"
                  << "-------------------------------------------\n"
                  << "-rx <float>  angular resolution in degrees (default "<<angular_resolution_x<<")\n"
                  << "-ry <float>  angular resolution in degrees (default "<<angular_resolution_y<<")\n"
                  << "-c <int>     coordinate frame (default "<< (int)coordinate_frame<<")\n"
                  << "-l           live update - update the range image according to the selected view in the 3D viewer.\n"
                  << "-h           this help\n"
                  << "\n\n";
}

void setViewerPose (pcl::visualization::PCLVisualizer& viewer, const Eigen::Affine3f& viewer_pose)
{
      Eigen::Vector3f pos_vector = viewer_pose * Eigen::Vector3f(0, 0, 0);
      Eigen::Vector3f look_at_vector = viewer_pose.rotation () * Eigen::Vector3f(0, 0, 1) + pos_vector;
      Eigen::Vector3f up_vector = viewer_pose.rotation () * Eigen::Vector3f(0, -1, 0);
      viewer.setCameraPosition (pos_vector[0], pos_vector[1], pos_vector[2],
                              look_at_vector[0], look_at_vector[1], look_at_vector[2],
                              up_vector[0], up_vector[1], up_vector[2]);
}

// --------------
// -----Main-----
// --------------
int main (int argc, char** argv)
{
      // --------------------------------------
      // -----Parse Command Line Arguments-----
      // --------------------------------------
      if (pcl::console::find_argument (argc, argv, "-h") >= 0)
      {
            printUsage (argv[0]);
            return 0;
      }
      if (pcl::console::find_argument (argc, argv, "-l") >= 0)
      {
            live_update = true;
            std::cout << "Live update is on.\n";
      }
      if (pcl::console::parse (argc, argv, "-rx", angular_resolution_x) >= 0)
            std::cout << "Setting angular resolution in x-direction to "<<angular_resolution_x<<"deg.\n";
      if (pcl::console::parse (argc, argv, "-ry", angular_resolution_y) >= 0)
            std::cout << "Setting angular resolution in y-direction to "<<angular_resolution_y<<"deg.\n";
      int tmp_coordinate_frame;
      if (pcl::console::parse (argc, argv, "-c", tmp_coordinate_frame) >= 0)
      {
            coordinate_frame = pcl::RangeImage::CoordinateFrame (tmp_coordinate_frame);
            std::cout << "Using coordinate frame "<< (int)coordinate_frame<<".\n";
      }
      angular_resolution_x = pcl::deg2rad (angular_resolution_x);
      angular_resolution_y = pcl::deg2rad (angular_resolution_y);
      
      // ------------------------------------------------------------------
      // -----读取点云,如果没有提供则创建一个-----
      // ------------------------------------------------------------------
      pcl::PointCloud<PointType>::Ptr point_cloud_ptr (new pcl::PointCloud<PointType>);
      pcl::PointCloud<PointType>& point_cloud = *point_cloud_ptr;
      Eigen::Affine3f scene_sensor_pose (Eigen::Affine3f::Identity ());
      std::vector<int> pcd_filename_indices = pcl::console::parse_file_extension_argument (argc, argv, "pcd");
      if (!pcd_filename_indices.empty ())
      {
            std::string filename = argv[pcd_filename_indices[0]];
            if (pcl::io::loadPCDFile (filename, point_cloud) == -1)
            {
                  std::cout << "Was not able to open file \""<<filename<<"\".\n";
                  printUsage (argv[0]);
                  return 0;
            }
            scene_sensor_pose = Eigen::Affine3f (Eigen::Translation3f (point_cloud.sensor_origin_[0],
                                                                        point_cloud.sensor_origin_[1],
                                                                        point_cloud.sensor_origin_[2])) *
                                    Eigen::Affine3f (point_cloud.sensor_orientation_);
            
      }
      else
      {
      std::cout << "\nNo *.pcd file given => Generating example point cloud.\n\n";
      for (float x=-0.5f; x<=0.5f; x+=0.01f)
      {
            for (float y=-0.5f; y<=0.5f; y+=0.01f)
            {
                  PointType point;  point.x = x;  point.y = y;  point.z = 2.0f - y;
                  point_cloud.push_back (point);
            }
      }
      point_cloud.width = point_cloud.size ();  point_cloud.height = 1;
      }
      
      // -----------------------------------------------
      // -----创建一个距离图像-----
      // -----------------------------------------------
      float noise_level = 0.0;
      float min_range = 0.0f;
      int border_size = 1;
      pcl::RangeImage::Ptr range_image_ptr(new pcl::RangeImage);
      pcl::RangeImage& range_image = *range_image_ptr;   
      range_image.createFromPointCloud (point_cloud, angular_resolution_x, angular_resolution_y,
                                          pcl::deg2rad (360.0f), pcl::deg2rad (180.0f),
                                          scene_sensor_pose, coordinate_frame, noise_level, min_range, border_size);
      
      // --------------------------------------------
      // -----创建3D查看器对象并添加点云-----
      // --------------------------------------------
      pcl::visualization::PCLVisualizer viewer ("3D Viewer");
      viewer.setBackgroundColor (1, 1, 1); // 背景颜色设置为白色
      pcl::visualization::PointCloudColorHandlerCustom/<pcl::PointWithRange> range_image_color_handler (range_image_ptr, 0, 0, 0); // 黑色
      viewer.addPointCloud (range_image_ptr, range_image_color_handler, "range image");
      viewer.setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, "range image");
      //  viewer.addCoordinateSystem (1.0f, "global");    // 用于添加坐标系  
      PointCloudColorHandlerCustom<PointType> point_cloud_color_handler (point_cloud_ptr, 150, 150, 150);
      viewer.addPointCloud (point_cloud_ptr, point_cloud_color_handler, "original point cloud"); // 可视化原始点云
      viewer.initCameraParameters ();
      setViewerPose(viewer, range_image.getTransformationToWorldSystem ());  // 将查看器中的查看位置设置为范围图像中的传感器位置
      
      // --------------------------
      // -----显示距离图像----- 
      // --------------------------
      pcl::visualization::RangeImageVisualizer range_image_widget ("Range image");
      range_image_widget.showRangeImage (range_image);
      
      //--------------------
      // -----Main loop-----
      //--------------------
      while (!viewer.wasStopped ())
      {
            //  spinOnce（）处理RangeImageVisualizer和viewer的当前事件
            range_image_widget.spinOnce ();
            viewer.spinOnce ();
            pcl_sleep (0.01);
            if (live_update)  // 根据3D查看器中的当前透视图更新距离图像：
            {
                  scene_sensor_pose = viewer.getViewerPose();
                  range_image.createFromPointCloud (point_cloud, angular_resolution_x, angular_resolution_y,
                                                pcl::deg2rad (360.0f), pcl::deg2rad (180.0f),
                                                scene_sensor_pose, pcl::RangeImage::LASER_FRAME, noise_level, min_range, border_size);
                  range_image_widget.showRangeImage (range_image);
            }
      }
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.5 FATAL_ERROR)

project(range_image_visualization)

find_package(PCL 1.3 REQUIRED)

include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})

add_executable (range_image_visualization range_image_visualization.cpp)
target_link_libraries (range_image_visualization ${PCL_LIBRARIES})

编译并运行

$ ./range_image_visualization -c 0

$ ./range_image_visualization sphere100.pcd

也可以使用参数-l根据3D查看器中的当前视图更新范围图像：

./range_image_visualization sphere100.pcd -l

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