What does convex hull do?
In computational geometry, a number of algorithms are known for computing the convex hull for a finite set of points and for other geometric objects. Computing the convex hull means constructing an unambiguous, efficient representation of the required convex shape.
What is convex hull in GIS?
The convex hull is a polygon with shortest perimeter that encloses a set of points. As a visual analogy, consider a set of points as nails in a board. The convex hull of the points would be like a rubber band stretched around the outermost nails.
What does the concave hull of a set of points look like?
Fortunately, there are alternatives to this state of affairs: we can calculate a concave hull. Here’s what the concave hull looks like when applied to the same set of points as in the previous image: Or maybe this one: As you can see, and contrary to the convex hull, there is no single definition of what the concave hull of a set of points is.
How to calculate a concave Hull polygon for a plane?
In this tutorial we will learn how to calculate a simple 2D hull polygon (concave or convex) for a set of points supported by a plane. First, download the dataset table_scene_mug_stereo_textured.pcd and save it somewhere to disk.
Can a concave hull be used as a discriminator?
This is a well-understood algorithm but suffers from the problem of not handling concave shapes, like this one: This shape does not correctly capture the essence of the underlying points. Were it used as a discriminator, some points would be incorrectly classified as being inside the cluster when they are not.
How to create a concavehull object in point cloud?
The real interesting part is in the lines below, where the ConcaveHull object gets created and the reconstruction is performed: Add the following lines to your CMakeLists.txt file: After you have made the executable, you can run it. Simply do: You will see something similar to: PointCloud after filtering has: 139656 data points.