[PCL self study: pclvisualizer] point cloud visualization tool pclvisualizer

One 、 What is? PCLVisualizer

  PCLVisualizer yes PCL Full function visualization class of . Although it is better than CloudViewer More complicated , But it is also more powerful , Provides display normals 、 Drawing shapes and multiple views .

Two 、 Use cases

   In this section, we will use the history presentation PCLVisualizer The usage and some features of , Including visual single point cloud , Adding color , Custom color , Show normals and other information 、 Multi window display and other functions .
   Please refer to the following code , The notes are very clear .

 /*  Sample code author ： Geoffrey Biggs */

 #include <iostream>
 #include <thread>
 
 #include <pcl/common/angles.h> // for pcl::deg2rad
 #include <pcl/features/normal_3d.h>
 #include <pcl/io/pcd_io.h>
 #include <pcl/visualization/pcl_visualizer.h>
 #include <pcl/console/parse.h>
 
 using namespace std::chrono_literals;
 
 // ---------------------
 // ----- Display help information -----
 // ---------------------
 void
 printUsage (const char* progName)
 {
    
   std::cout << "\n\nUsage: "<<progName<<" [options]\n\n"
             << "Options:\n"
             << "-------------------------------------------\n"
             << "-h this help\n"
            << "-s Simple visualisation example\n"
            << "-r RGB colour visualisation example\n"
             << "-c Custom colour visualisation example\n"
            << "-n Normals visualisation example\n"
             << "-a Shapes visualisation example\n"
             << "-v Viewports example\n"
             << "-i Interaction Customization example\n"
             << "\n\n";
 }
 
 
 pcl::visualization::PCLVisualizer::Ptr simpleVis (pcl::PointCloud<pcl::PointXYZ>::ConstPtr cloud)
 {
    
   // -------------------------------------------------
   // ----- Open the 3D visualization tool PCLVisualizer And add a normal point cloud -----
   // -------------------------------------------------
   pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
   viewer->setBackgroundColor (0, 0, 0);//  Set the background color 
   viewer->addPointCloud<pcl::PointXYZ> (cloud, "sample cloud");//  Add a point cloud to the window sample cloud
   viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, "sample cloud"); //  Set the size of a single point of the point cloud 
   viewer->addCoordinateSystem (1.0);//  Add coordinate system 
   viewer->initCameraParameters (); //  Initialize camera parameters 
   return (viewer);
 }
 
 
 pcl::visualization::PCLVisualizer::Ptr rgbVis (pcl::PointCloud<pcl::PointXYZRGB>::ConstPtr cloud)
 {
    
   // -------------------------------------------------
   // ----- Open the 3D visualization tool PCLVisualizer And add RGB Color point cloud -----
   // -------------------------------------------------
   pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
   viewer->setBackgroundColor (0, 0, 0);
   pcl::visualization::PointCloudColorHandlerRGBField<pcl::PointXYZRGB> rgb(cloud); //  establish RGB Point cloud handle , Used to add RGB Point cloud 
   viewer->addPointCloud<pcl::PointXYZRGB> (cloud, rgb, "sample cloud");
   viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud");
   viewer->addCoordinateSystem (1.0);
   viewer->initCameraParameters ();
   return (viewer);
 }
 
 
 pcl::visualization::PCLVisualizer::Ptr customColourVis (pcl::PointCloud<pcl::PointXYZ>::ConstPtr cloud)
 {
    
   // -----------------------------------------------
   // ---- Open the 3D visualization tool PCLVisualizer And add the specified color point cloud ----
   // -----------------------------------------------
   pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
   viewer->setBackgroundColor (0, 0, 0);
   pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> single_color(cloud, 0, 255, 0); //  Set the point cloud of the specified color ( green )
   viewer->addPointCloud<pcl::PointXYZ> (cloud, single_color, "sample cloud");
   viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud");
   viewer->addCoordinateSystem (1.0);
   viewer->initCameraParameters ();
   return (viewer);
 }
 

 pcl::visualization::PCLVisualizer::Ptr normalsVis (
     pcl::PointCloud<pcl::PointXYZRGB>::ConstPtr cloud, pcl::PointCloud<pcl::Normal>::ConstPtr normals)
 {
    
   // --------------------------------------------------------
   // ----- Open the 3D visualization tool PCLVisualizer And add point cloud and normal -----
   // --------------------------------------------------------
   pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
   viewer->setBackgroundColor (0, 0, 0);
   pcl::visualization::PointCloudColorHandlerRGBField<pcl::PointXYZRGB> rgb(cloud);
   viewer->addPointCloud<pcl::PointXYZRGB> (cloud, rgb, "sample cloud");
   viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud");
   viewer->addPointCloudNormals<pcl::PointXYZRGB, pcl::Normal> (cloud, normals, 10, 0.05, "normals");//  Show normal ,10 Show only 1/10 The normal direction of the point of ,0.05 Indicates the normal display length .
   viewer->addCoordinateSystem (1.0);
   viewer->initCameraParameters ();
   return (viewer);
 }
 
 
pcl::visualization::PCLVisualizer::Ptr shapesVis (pcl::PointCloud<pcl::PointXYZRGB>::ConstPtr cloud)
{
    
  // --------------------------------------------
  // ----- Open the 3D visualization tool PCLVisualizer And add a point cloud -----
  // --------------------------------------------
  pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
106  viewer->setBackgroundColor (0, 0, 0);
107  pcl::visualization::PointCloudColorHandlerRGBField<pcl::PointXYZRGB> rgb(cloud);
108  viewer->addPointCloud<pcl::PointXYZRGB> (cloud, rgb, "sample cloud");
109  viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud");
  viewer->addCoordinateSystem (1.0);
  viewer->initCameraParameters ();

  //------------------------------------
  //-----Add  Add point cloud of specified shape -----
  //------------------------------------
  viewer->addLine<pcl::PointXYZRGB> ((*cloud)[0],
                                     (*cloud)[cloud->size() - 1], "line"); //  Add a linear point cloud （ The connection between the first point and the last point of the point cloud ）
  viewer->addSphere ((*cloud)[0], 0.2, 0.5, 0.5, 0.0, "sphere");
  //  Add a spherical point cloud , The center is the first point position , The radius is 0.5, The last three parameters are color 

  //---------------------------------------
  //----- Add shapes in other places -----
  //---------------------------------------
  pcl::ModelCoefficients coeffs; //  Add polynomial coefficients to the model 
  coeffs.values.push_back (0.0);
  coeffs.values.push_back (0.0);
  coeffs.values.push_back (1.0);
  coeffs.values.push_back (0.0);
 	viewer->addPlane (coeffs, "plane"); // 4 A coefficient of ABCD You can define a plane 
  coeffs.values.clear ();
  coeffs.values.push_back (0.3);
  coeffs.values.push_back (0.3);
  coeffs.values.push_back (0.0);
  coeffs.values.push_back (0.0);
  coeffs.values.push_back (1.0);
  coeffs.values.push_back (0.0);
  coeffs.values.push_back (5.0);
  viewer->addCone (coeffs, "cone"); // 7 A coefficient of ABCDEFG You can define a cone 

  return (viewer);
}


pcl::visualization::PCLVisualizer::Ptr viewportsVis (
    pcl::PointCloud<pcl::PointXYZRGB>::ConstPtr cloud, pcl::PointCloud<pcl::Normal>::ConstPtr normals1, pcl::PointCloud<pcl::Normal>::ConstPtr normals2)
{
    
  // --------------------------------------------------------
  // ----- Add different point clouds and normal directions in the same window and display them side by side -----
  // --------------------------------------------------------
  pcl::visualization::PCLVisualizer::Ptr viewer (new 	   pcl::visualization::PCLVisualizer ("3D Viewer"));
 viewer->initCameraParameters ();

  int v1(0);
  viewer->createViewPort(0.0, 0.0, 0.5, 1.0, v1); //  Add perspective V1, The four parameters are X Axis and Y The maximum and minimum display range of the axis 
  viewer->setBackgroundColor (0, 0, 0, v1);
  viewer->addText("Radius: 0.01", 10, 10, "v1 text", v1);
 pcl::visualization::PointCloudColorHandlerRGBField<pcl::PointXYZRGB> rgb(cloud);
  viewer->addPointCloud<pcl::PointXYZRGB> (cloud, rgb, "sample cloud1", v1);

  int v2(0);
  viewer->createViewPort(0.5, 0.0, 1.0, 1.0, v2);
  viewer->setBackgroundColor (0.3, 0.3, 0.3, v2);
  viewer->addText("Radius: 0.1", 10, 10, "v2 text", v2);
  pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZRGB> single_color(cloud, 0, 255, 0);
  viewer->addPointCloud<pcl::PointXYZRGB> (cloud, single_color, "sample cloud2", v2);

  viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud1");
167  viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 3, "sample cloud2");
  viewer->addCoordinateSystem (1.0);

  viewer->addPointCloudNormals<pcl::PointXYZRGB, pcl::Normal> (cloud, normals1, 10, 0.05, "normals1", v1);
  viewer->addPointCloudNormals<pcl::PointXYZRGB, pcl::Normal> (cloud, normals2, 10, 0.05, "normals2", v2);

  return (viewer);
}

//  The following is the keyboard input response 
unsigned int text_id = 0;
void keyboardEventOccurred (const pcl::visualization::KeyboardEvent &event,
                            void* viewer_void)
{
    
  pcl::visualization::PCLVisualizer *viewer = static_cast<pcl::visualization::PCLVisualizer *> (viewer_void);
  if (event.getKeySym () == "r" && event.keyDown ())
  {
    
    std::cout << "r was pressed => removing all text" << std::endl;

    char str[512];
    for (unsigned int i = 0; i < text_id; ++i)
    {
    
      sprintf (str, "text#%03d", i);
      viewer->removeShape (str);
    }
    text_id = 0;
  }
}

//  Mouse event response 
void mouseEventOccurred (const pcl::visualization::MouseEvent &event,
                         void* viewer_void)
{
    
  pcl::visualization::PCLVisualizer *viewer = static_cast<pcl::visualization::PCLVisualizer *> (viewer_void);
  if (event.getButton () == pcl::visualization::MouseEvent::LeftButton &&
      event.getType () == pcl::visualization::MouseEvent::MouseButtonRelease)
  {
    
   std::cout << "Left mouse button released at position (" << event.getX () << ", " << event.getY () << ")" << std::endl;

    char str[512];
    sprintf (str, "text#%03d", text_id ++);
   viewer->addText ("clicked here", event.getX (), event.getY (), str);
  }
}

pcl::visualization::PCLVisualizer::Ptr interactionCustomizationVis ()
{
    
  pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
  viewer->setBackgroundColor (0, 0, 0);
  viewer->addCoordinateSystem (1.0);
//  Register keyboard and mouse response callback functions 
  viewer->registerKeyboardCallback (keyboardEventOccurred, (void*)viewer.get ());
  viewer->registerMouseCallback (mouseEventOccurred, (void*)viewer.get ());

  return (viewer);
}


// --------------
// -----Main-----
// --------------
int
main (int argc, char** argv)
{
    
  // --------------------------------------
  // ----- Command line parsing -----
  // --------------------------------------
  if (pcl::console::find_argument (argc, argv, "-h") >= 0)
  {
    
    printUsage (argv[0]);
    return 0;
  }
  bool simple(false), rgb(false), custom_c(false), normals(false),
    shapes(false), viewports(false), interaction_customization(false);
  if (pcl::console::find_argument (argc, argv, "-s") >= 0)
  {
    
    simple = true;
    std::cout << "Simple visualisation example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-c") >= 0)
  {
    
    custom_c = true;
   std::cout << "Custom colour visualisation example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-r") >= 0)
  {
    
    rgb = true;
    std::cout << "RGB colour visualisation example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-n") >= 0)
  {
    
    normals = true;
    std::cout << "Normals visualisation example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-a") >= 0)
  {
    
    shapes = true;
    std::cout << "Shapes visualisation example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-v") >= 0)
  {
    
    viewports = true;
    std::cout << "Viewports example\n";
  }
  else if (pcl::console::find_argument (argc, argv, "-i") >= 0)
  {
    
    interaction_customization = true;
    std::cout << "Interaction Customization example\n";
  }
  else
  {
    
    printUsage (argv[0]);
    return 0;
  }

  // ------------------------------------
  // ----- Create a sample point cloud -----
  // ------------------------------------
  pcl::PointCloud<pcl::PointXYZ>::Ptr basic_cloud_ptr (new pcl::PointCloud<pcl::PointXYZ>);
  pcl::PointCloud<pcl::PointXYZRGB>::Ptr point_cloud_ptr (new pcl::PointCloud<pcl::PointXYZRGB>);
  std::cout << "Generating example point clouds.\n\n";
 //  We're going to make an edge z Axis extruded ellipse .XYZRGB The color of the cloud will gradually change from red to green to blue .
  std::uint8_t r(255), g(15), b(15);
  for (float z(-1.0); z <= 1.0; z += 0.05)
  {
    
    for (float angle(0.0); angle <= 360.0; angle += 5.0)
    {
    
     pcl::PointXYZ basic_point;
      basic_point.x = 0.5 * std::cos (pcl::deg2rad(angle));
      basic_point.y = sinf (pcl::deg2rad(angle));
      basic_point.z = z;
      basic_cloud_ptr->points.push_back(basic_point);

      pcl::PointXYZRGB point;
      point.x = basic_point.x;
      point.y = basic_point.y;
      point.z = basic_point.z;
      point.r = r;
      point.g = g;
      point.b = b;
      point_cloud_ptr->points.push_back (point);
    }
    if (z < 0.0)
    {
    
      r -= 12;
      g += 12;
    }
    else
    {
    
      g -= 12;
      b += 12;
    }
  }
  basic_cloud_ptr->width = basic_cloud_ptr->size ();
  basic_cloud_ptr->height = 1;
  point_cloud_ptr->width = point_cloud_ptr->size ();
  point_cloud_ptr->height = 1;

  // ----------------------------------------------------------------
  // ----- Calculate the normal direction of the surface , Search radius 0.05-----
  // ----------------------------------------------------------------
  pcl::NormalEstimation<pcl::PointXYZRGB, pcl::Normal> ne;
  ne.setInputCloud (point_cloud_ptr);
  pcl::search::KdTree<pcl::PointXYZRGB>::Ptr tree (new pcl::search::KdTree<pcl::PointXYZRGB> ());
  ne.setSearchMethod (tree);
  pcl::PointCloud<pcl::Normal>::Ptr cloud_normals1 (new pcl::PointCloud<pcl::Normal>);
  ne.setRadiusSearch (0.05);
  ne.compute (*cloud_normals1);

  // ---------------------------------------------------------------
  // ----- Calculate the normal direction of the surface , Search radius 0.1-----
  // ---------------------------------------------------------------
  pcl::PointCloud<pcl::Normal>::Ptr cloud_normals2 (new pcl::PointCloud<pcl::Normal>);
  ne.setRadiusSearch (0.1);
  ne.compute (*cloud_normals2);

//  Start displaying point clouds 
  pcl::visualization::PCLVisualizer::Ptr viewer;
  if (simple)
  {
    
    viewer = simpleVis(basic_cloud_ptr);
  }
  else if (rgb)
  {
    
    viewer = rgbVis(point_cloud_ptr);
  }
  else if (custom_c)
  {
    
    viewer = customColourVis(basic_cloud_ptr);
  }
  else if (normals)
  {
    
      viewer = normalsVis(point_cloud_ptr, cloud_normals2);
  }
  else if (shapes)
  {
    
    viewer = shapesVis(point_cloud_ptr);
  }
  else if (viewports)
  {
    
    viewer = viewportsVis(point_cloud_ptr, cloud_normals1, cloud_normals2);
  }
  else if (interaction_customization)
  {
    
    viewer = interactionCustomizationVis();
  }

  //--------------------
  // -----Main loop-----
  //--------------------
  while (!viewer->wasStopped ())
 {
    
    viewer->spinOnce (100);
    std::this_thread::sleep_for(100ms);
  }
}

The view of the above operation is shown below ：
1. Ordinary point cloud

2.RGB Point cloud

3. Monochromatic point cloud

4.RGB Point cloud with normal

5.RGB Point cloud with normal , And create lines 、 Conic and spherical point clouds

6. Two point clouds in one view

7. Mouse response and keyboard response

---

【 About bloggers 】
   Stanford rabbit , male , Master of engineering, Tianjin University . Since graduation, I have been engaged in optical three-dimensional imaging and point cloud processing . Because the three-dimensional processing library used in work is the internal library of the company , Not universally applicable , So I learned to open source by myself PCL Library and its related mathematical knowledge for use . I would like to share the self-study process with you .
Bloggers lack of talent and knowledge , Not yet able to guide , If you have any questions, please leave a message in the comments section for everyone to discuss .