The Ture3D Modeling Method Based On Point Cloud Data

With the progress of science and technology and the development of human society, the3D laser scanner is currently a hot research topic in the field of surveying and mapping geographic information. Because of two-dimensional surveying and mapping results have restrict people to the various needs of social life, coupled with the instrument and advocacy of the concept of digital city, making3D, virtualization and reality become the common goal. Compared to the two-dimensional model, Three-dimensional model not only intuitive and visual effect is better, express more completely and accurately three-dimensional model information.The data source objectively must be accurate and complete.In this paper it systematically expounds the composition of3D laser scanner system (laser ranging system, laser scanning system and support system), The laser ranging technology already quite mature at present.In the field of Surveying, three-dimensional laser scanner is pulsed ranging method TOF. In this paper, an experiment using a phase-type scanners ranging principle of American foreign Trimble FX extends to the several commonly used three-dimensional laser scanner brands exhaustive list of parameters 3D laser scanning technology as a new measurement techniques, can get quickly directly and accurately three-dimensional surface point feature information and data,that point cloud data. This techniques Reverse engineering is now being widely used in the field of modeling techniques such as copying e-commerce, automotive, antiques and crafts, medical restoration,3D animation, and anthropometric measures. However, most of these applications is close contact three-dimensional modeling, and feature three-dimensional modeling base material shape modeling can be divided into regular shapes and irregular shape modeling. Irregularly shaped three-dimensional modeling, also called traditional three-dimensional modeling, is to extract the contour feature in CAD software, is relatively simple, rough. Irregular three-dimensional modeling method is now more, and according to the different modeling methods, along with modeling results vary.This, in a city office building chemical plants is studied, finishing the two stations measuring data, and the two sites were pretreated cloud data. Useing is now more popular two modeling methods, based on adaptive CS-RBF algorithm modeling methods and modeling method based on multi-scale CS-RBF algorithm. Then finishing with two three-dimensional model of the site generated cloud data were verified and comparative study By comparison of its advantages and disadvantages, but no method to achieve the ideal of true three-dimensional model, then we propose a modified convex hull algorithm, its main idea is that the three-dimensional problem turn to two-dimensional, two-dimensional algorithm has been thinked quite mature, so at the first point cloud data is stratificated, the first layer of point cloud data is processed, and multiple calls to the convex hull algorithm, layers of point cloud data processing convex hull algorithm called several times, and ultimately achieve satisfactory results for user.