【作者】 马宇博；

【导师】 周明全；

【作者基本信息】 西北大学 ， 计算机应用与技术， 2008， 硕士

【摘要】 随着计算机硬件、虚拟现实技术、可视化技术及图形学等各学科的迅猛发展,近年来发展了一个新的领域——真实感场景重建。这一技术在文物的计算机重建、虚拟展示以及破损文物的计算机重构中起着非常重要的作用,有着广泛的应用前景。针对大场景重建过程存在的数据量大存在冗余、场景信息不完备等问题,对真实感大场景的重建技术进行了深入的研究,主要研究内容如下:1)建立地形和地物的三维模型。利用Cyra三维激光扫描系统对采集到的点云数据作简化等预处理工作。基于OpenGL对地形、地物数据分别采用规则网格、不规则网格两种建模方式,建立地形模型采用DEM数据组织方式,建立地物模型采用改进的Delaunay三角剖分方法。这样做避免了由一种建模方法带来的大量数据冗余,对模型的层次细节显示作了很好的铺垫。2)基于层次细节(LOD)场景简化技术中的ROAM算法,给出了该算法的分块改进策略。针对三维地形数据量大,显示时不易全部显示所有模型的特点,考虑视距和地形情况,实现对ROAM算法的分块改进,应用于实现地形的实时渲染,动态的改变地形显示的层次细节,有效的节约了计算资源,提高了数据的处理速度。3)设计并实现了真实感三维大场景可视化系统。以小雁塔场景真实感的设计与实现为例,实验验证了本文研究成果的可行性与有效性。总之,本文提出的解决方案在一定程度上有效的解决了目前真实感场景重建中存在的问题。更多还原

【Abstract】 With the rapid development of various technologies, such as computer hardware, virtual reality technology, visualization and graphics, a new field - Realistic scene reconstruction has developed in recent years. This technology plays a very important role in the computer reconstruction of historic relic, virtual display and the computer reconstruction of damaged relic. The scenes for the reconstruction process there exist ? large amount of data redundancy, incomplete scenes information and other issues, the realistic scene of the reconstruction carried out in-depth research, mainly on the following:Focus on the establishment of 3D model of the terrain and building. We take pretreatment of data by Cyra 3D laser scanner. Based on OpenGL, the terrain is reconstructed on grid methods and the building is reconstructed on irregular methods. Terrain model using DEM data form and improved Delaunay Triangulation method is used in the building reconstruction.This can avoid the large number of data redundancy by using only one Modeling methods. It makes a good foreshadowing of the model level of detail shows.Based on the level of detail (LOD) technology to simplify scenes in the ROAM algorithm, given the algorithm to improve the block strategy. For 3D terrain data, shows that when all the models show that not all the characteristics, consider distance of seeing and the terrain circumstance, the realization of the ROAM algorithm to improve the block, be used to achieve real-time rendering of the terrain, dynamic changes in topography shows that the level of details, economize the calculation resources effectively, raise the processing speed of the data.Designing and implementing a Realistic scenes 3D visualization system. As an example small wild goose pagoda realistic scene has been has been designed and implemented, experimental verification of the results of this study on the feasibility and effectiveness.In short, the solution proposed by this paper solves some problems of Realistic scene reconstruction in a certain degree effectively.更多还原