concave_hull.cpp

bool findConcaveHull(pcl::PointCloud <pcl::PointXYZRGB>::Ptr cloud, pcl::PointCloud <pcl::PointXYZRGB>::Ptr &hull)
{

  pcl::PointCloud<pcl::PointXYZRGB>::Ptr cloud_projected (new pcl::PointCloud<pcl::PointXYZRGB>);
    pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients);

    pcl::PointIndices::Ptr inliers (new pcl::PointIndices);
  // Create the segmentation object
  pcl::SACSegmentation<pcl::PointXYZRGB> seg;
  // Optional
  seg.setOptimizeCoefficients (true);
  // Mandatory
  seg.setModelType (pcl::SACMODEL_PLANE);
  seg.setMethodType (pcl::SAC_RANSAC);
  seg.setDistanceThreshold (0.01);

  seg.setInputCloud (cloud);
  seg.segment (*inliers, *coefficients);
   std::cerr << "PointCloud after segmentation has: "
            << inliers->indices.size () << " inliers." << std::endl;

  pcl::ProjectInliers<pcl::PointXYZRGB> proj;
  proj.setModelType (pcl::SACMODEL_PLANE);
  proj.setIndices (inliers);
  proj.setInputCloud (cloud);
  proj.setModelCoefficients (coefficients);
  proj.filter (*cloud_projected);

  pcl::ConcaveHull<pcl::PointXYZRGB> chull;
  chull.setInputCloud (cloud_projected);
  chull.setAlpha (0.1);
  chull.reconstruct (*hull);

   std::cerr << "Concave hull has: " << hull->points.size ()
            << " data points." << std::endl;

   std::cout<< "Dimensionality: "<< chull.getDimension () << std::endl;

   for (size_t i =0; i < hull->points.size() ; ++i)
   {
     std::cout << "Point " << i << " : [" << hull->points[i].x << ", " << hull->points[i].y << ", " << hull->points[i].z << std::endl;
   }

  return true;
}