基于PCL的屏幕选点、框选点云、单点选取

1. 单点选取

#include <pcl/io/pcd_io.h>
#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/visualization/pcl_visualizer.h>

typedef pcl::PointXYZRGBA PointT;
typedef pcl::PointCloud<PointT> PointCloudT;

// Mutex: //
boost::mutex cloud_mutex;

struct callback_args
{
	// structure used to pass arguments to the callback function
	PointCloudT::Ptr clicked_points_3d;
	pcl::visualization::PCLVisualizer::Ptr viewerPtr;
};

void pp_callback(const pcl::visualization::PointPickingEvent& event, void* args)
{
	struct callback_args* data = (struct callback_args *)args;
	if (event.getPointIndex() == -1)
		return;
	PointT current_point;
	event.getPoint(current_point.x, current_point.y, current_point.z);
	data->clicked_points_3d->points.push_back(current_point);
	// Draw clicked points in red:
	pcl::visualization::PointCloudColorHandlerCustom<PointT> red(data->clicked_points_3d, 255, 0, 0);
	data->viewerPtr->removePointCloud("clicked_points");
	data->viewerPtr->addPointCloud(data->clicked_points_3d, red, "clicked_points");
	data->viewerPtr->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 10, "clicked_points");
	std::cout << current_point.x << " " << current_point.y << " " << current_point.z << std::endl;
}
void main()
{
	std::string filename("bunny.pcd");
	//visualizer
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>());
	boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer(new pcl::visualization::PCLVisualizer("viewer"));

	if (pcl::io::loadPCDFile(filename, *cloud))
	{
		std::cerr << "ERROR: Cannot open file " << filename << "! Aborting..." << std::endl;
		return;
	}
	std::cout << cloud->points.size() << std::endl;
	//viewer->addPointCloud(cloud, "bunny");

	cloud_mutex.lock();    // for not overwriting the point cloud

	// Display pointcloud:
	viewer->addPointCloud(cloud, "bunny");
	viewer->setCameraPosition(0, 0, -2, 0, -1, 0, 0);

	// Add point picking callback to viewer:
	struct callback_args cb_args;
	PointCloudT::Ptr clicked_points_3d(new PointCloudT);
	cb_args.clicked_points_3d = clicked_points_3d;
	cb_args.viewerPtr = pcl::visualization::PCLVisualizer::Ptr(viewer);
	viewer->registerPointPickingCallback(pp_callback, (void*)&cb_args);
	std::cout << "Shift+click on three floor points, then press 'Q'..." << std::endl;
	// Spin until 'Q' is pressed:
	viewer->spin();
	std::cout << "done." << std::endl;

	cloud_mutex.unlock();

	while (!viewer->wasStopped())
	{
		viewer->spinOnce(100);
		boost::this_thread::sleep(boost::posix_time::microseconds(100000));
	}
}

　　

注意：点的选取，需要同时按住shift和鼠标左键

2. 区域选点

#include <pcl/io/pcd_io.h>
#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/filters/voxel_grid.h>
#include <iostream>
#include <vector>

pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>());
boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer(new pcl::visualization::PCLVisualizer("viewer"));
pcl::PointCloud<pcl::PointXYZ>::Ptr clicked_points_3d(new pcl::PointCloud<pcl::PointXYZ>);
int num = 0;

void pp_callback(const pcl::visualization::AreaPickingEvent& event, void* args)
{
    std::vector< int > indices;
    if (event.getPointsIndices(indices)==-1)
        return;

    for (int i = 0; i < indices.size(); ++i)
    {
        clicked_points_3d->points.push_back(cloud->points.at(indices[i]));
    }

    pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> red(clicked_points_3d, 255, 0, 0);

    std::stringstream ss;
    std::string cloudName;
    ss << num++;
    ss >> cloudName;
    cloudName += "_cloudName";

    viewer->addPointCloud(clicked_points_3d, red, cloudName);
    viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 10, cloudName);
}

void main()
{
    if (pcl::io::loadPCDFile("bunny.pcd", *cloud))
    {
        std::cerr << "ERROR: Cannot open file " << std::endl;
        return;
    }
    viewer->addPointCloud(cloud, "bunny");
    viewer->setCameraPosition(0, 0, -2, 0, -1, 0, 0);
    viewer->registerAreaPickingCallback(pp_callback, (void*)&cloud);

    //VoxelGrid
    pcl::VoxelGrid<pcl::PointXYZ> vgF;
    vgF.setInputCloud(cloud);
    vgF.setLeafSize(0.1, 0.1, 0.1);
    vgF.filter(*cloud);

    while (!viewer->wasStopped())
    {
        viewer->spinOnce(100);
        boost::this_thread::sleep(boost::posix_time::microseconds(100000));
    }
}