A point cloud is a set of data points in some coordinate system.
In a three-dimensional coordinate system, these points are
usually defined by X, Y, and Z coordinates, and often are
intended to represent the external surface of an object. Point
clouds may be created by 3D scanners. These devices measure in
an automatic way a large number of points on the surface of an
object, and often output a point cloud as a data file. The point
cloud represents the set of points that the device has measured.
As the result of a 3D scanning process point clouds are used for
many purposes, including to create 3D CAD models for
manufactured parts, metrology/quality inspection, and a
multitude of visualization, animation, rendering and mass
customization applications. While point clouds can be directly
rendered and inspected, usually point clouds themselves are
generally not directly usable in most 3D applications, and
therefore are usually converted to polygon mesh or triangle mesh
models, NURBS surface models, or CAD models