Convex hull detection and convex hull vertex solution of PCL point cloud Library

Convex hull detection of point cloud is more commonly used. PCL comes with Convex hull detection ConvexHull, which is a relatively simple function. Set the dimension setDimension of ConvexHull, and record it here
Header: #include <; pcl/surface/convex_hull.h>
	pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
	pcl::io::loadPCDFile<pcl::PointXYZ>("bun_45.pcd", *cloud);

	pcl::ConvexHull<pcl::PointXYZ> hull;                  
	hull.setInputCloud(cloud);                   
	hull.setDimension(3);

	std::vector<pcl::Vertices> polygons;                 
	pcl::PointCloud<pcl::PointXYZ>::Ptr surface_hull(new pcl::PointCloud<pcl::PointXYZ>);
	hull.reconstruct(*surface_hull, polygons);           

	cout << surface_hull->size() << endl;

	// ---------------------- Visualizer -------------------------------------------
	boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer(new pcl::visualization::PCLVisualizer);
	viewer->setBackgroundColor(255,255,255);

	pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> color_handler(cloud, 255, 255, 0);
	viewer->addPointCloud(cloud, color_handler, "sample cloud");
	viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 6, "sample cloud");

	pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZ> color_handlerK(surface_hull, 255, 0, 0);
	viewer->addPointCloud(surface_hull, color_handlerK, "point");
	viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 6, "point");

	//viewer->addPolygon<pcl::PointXYZ>(surface_hull, 0, 0, 255, "polyline");

	while (!viewer->wasStopped())
	{
		viewer->spinOnce(100);
	}

Adopting Stanford Rabbit Point Cloud, the effect is shown in the figure below:

If the point cloud in a certain convex hull is further separated from the scene, Crophull can be used for filtering
CropHull filtering can refer to: https://blog.csdn.net/zfjBIT/article/details/92795689
Thanks for the correction of Xiao snail. If we get the convex hull curve, further triangulation is needed. It is not correct to connect the convex hull points only


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