A Method of Extracting Geometric Information from the Point Cloud of Building

The purpose of this article is to extract geometric features and other information for polyhedron, then using these features and information to build the model of object. In this essay, polyhedron refers to objects such as buildings. Unlike modelling objects in other fields, like reverse engineering, buildings’ surface usually consists of large amount of big and plane surfaces. Among these surfaces, there are distinct points and lines of intersection (the edges and vertices of the polyhedron). In this article, Triangles classification and Surface extraction, Surface contiguous relations restoration, and Polyhedron Vertices solution and Polyhedron model Reconstruction constitute the main research of extracting geometric features and building the model of the object. In this contribution, some examples of extracting information from the point cloud are presented to demonstrate the method, which is put forward in this essay. Besides, the results prove that when the geometric information of vertices, edges and surfaces, together with the topological relations among them, are extracted from the point cloud, the model of polyhedron, representative of building in this essay, can be built effectively. Equally important, models generated from this method, while occupy less memory space, they can store more comprehensive structural information, and have a better exhibitive effect.