Recovering Of 3D Surfaces

Reverse engineering is a new subject and technology coming up with the development of computer science and data digitization. It's help to change the design mode from draft to models in conventional CAD systems. It's a new approach for rapid prototype manufacture. surface reconstruction and Recovering are one basilica questions in reverse engineering. With the data acquired from one existent object, the geometrical models can be reconstructed which is a useful tools to study the existent object such as analysis, computing and rendering. This thesis centers on the issue of surface reconstruction and recovering. New recovering algorithm of sharp edges using two steps smoothing is proposed. The main content reads as follows:This thesis centers on the issue of surface reconstruction and recovering. New recovering algorithm of sharp edges using two steps smoothing is proposed. The main content reads as follows:Chapter 1 gives a survey on the study of reverse engineering of shapes. Some results on the emphases of reverse engineering-surface reconstructionare and recovering proposed. And then we show our studies. Then,the 3-D data acquisition and processing are introduced, including three-dimensional discrete data acquisition and processing.In the next chapter, an introduction to classical 3D smoothing algorithms as well as some new smoothing methods in the recent years is presented .After analyzing and summarizing the fundamental theories,the disadvantages and advantages of different methods are induced,and the paper presents a simple and removes noise effectively ,while can preserves desirable geometric features .our algorithm can smooth mesh by two steps, Firstly noisy face normals vector are filtered by preudotriangles .Secondly ,vertex positions are iteratively updated to agree with the denoised face normalsIn chapter 4,this paper presents a robust simple approach conducting two-step filters to recover sharp edges. This algorithm first through two steps realizes mesh smoothing, and then identifies the smooth region through the dihedral angle and the non-smooth region, simultaneously through the introduction dynamic triangle and its segmentation, and then connected through the triangular method of calculation to insert normal vector vertex coordinates.After processing can reduce L2 obviously the error.In chapter 5 ,the main results are proposed and the main points in future studies are briefly introduced...