Research On Feature Line Extraction And Distinguish The Outer Surface From The Fracture Surface Of3D Model Culture Relics

Cultural heritage is an important resource of a country, using the information technology to protect Chinese cultural heritage, is the trend of archeology and heritage conservation work development. To get the feature lines of the Heritage models and distinguish the outer surface from the fracture surface are both the basis for achieving the automation archaeological heritage restoration and virtual display. They are also the emphasis in this paper. First, calculate the curvature of the surface to get the features of the artifacts model. Then, identify the faces on the artifacts fragments, it means to distinguish the outer surface from the fracture surface on the model, and to show the results. The main research progresses of this thesis are summarized as follows:(1) Scanning the unearthed terracotta fragments by the three-dimensional laser scanner, in order to get the most basic information of the three-dimensional grids. Through processing this basic information of these three-dimensional grids, including de-noising, fill holes, and simplify it, to obtain a three-dimensional model can be used for feature extraction.(2) After analyzing and comparing the feature extraction methods of Artifacts models, a method to get the features of the artifacts model by calculating the curvature of the surface is given, and this method is according to the methods of feature extraction of point cloud model. The first thing in this method is to find r-neighbor points loop sequence. After that using the mesh surface curvature calculation method to get the curvature distribution on the model surfaces.(3) Giving an improvement of the existing polyline growing algorithm, then using this method to line the feature point that has been calculated, at the same time determine the visibility of the line. Eliminate hidden lines by combine the method called scan line algorithm and the back face discrimination, finally get the fairing characteristic lines.(4) Through study the surfaces division technology, and according to the requirements of the feature line extraction and the outer surface and the fracture surface distinguish of the Artifacts three-dimensional models, a surface segmentation method based on the edge is used to divide the model into several surface. Then distinguish the outer surface and the fracture surface according to the degree of changes between the normal vectors on different surface.(5) Designed and developed the feature line extraction and the outer surface and the fracture surface distinguish system according to the views above. This system is practical and can meet the requirements of the feature line extraction and the outer surface and the fracture surface distinguish. It provides a new environment to artifacts virtual recovery and display.In summary, this paper focuses on solving the problem of the secondary injury in virtual restoration and exhibition of Artifacts, provided a strong support to the computer-aided heritage conservation work.