获取飞机的角点

Question

Based on this tutorial: http://pointclouds.org/documentation/tutorials/planar_segmentation.php

I have segmented my planes as stated in the tutorial

pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients);
pcl::PointIndices::Ptr inliers (new pcl::PointIndices);   // Create the segmentation object  
pcl::SACSegmentation<pcl::PointXYZ> 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);

if (inliers->indices.size() == 0) {
   PCL_ERROR ("Could not estimate a planar model for the given dataset.");
   return (-1);  
}

std::cerr << "Model coefficients: " << coefficients->values[0] << " " 
                      << coefficients->values[1] << " "
                      << coefficients->values[2] << " " 
                      << coefficients->values[3] << std::endl;

Now, I'd like to know if there is a way to get the corner points. Or if such a method is available in PCL?

If not, how may I solve this problem.

Answer 1

When you segment a plane in a point cloud, you find points lying on the same plane; the output is not necessarily a rectangle or a square; so the corners might not exists at all.

What you could do is create a polygon but iterating over the outside points of the points an build a polygon. Take a look at the 2D hull PCL tutorial on how to build a hull from a set of points lying on a plane.

After that you can estimate the angles at each point of your polygon thanks to the previous and next vectors. Beware of concave polygons with angle greater than 180°!