【作者】 赵敬红；

【导师】 向南平；

【作者基本信息】 中南大学 ， 摄影测量与遥感， 2009， 硕士

【摘要】 三维地形在城市规划、工程勘查与设计、环境监测、灾害预报、军事、游戏娱乐等诸多领域都有广泛的应用。如何实现基于海量数据的大规模三维地形的可视化更是目前研究的热点,本文就此问题做了如下研究:(一)地形数字表达方法及格网数字高程模型数据的内插方法,重点对基于四叉树数据结构的地形简化技术进行了研究,总结得出OSG地形简化流程。(二)通过对DEM数据和纹理数据的分层、分块等处理构建了金字塔数据模型(四叉树细节层次模型),为地形的多分辨率显示直接提供数据而无需实时化简。总结得出OSG的分层分块方案。(三)研究海量数据调度机制、裂缝产生规律、纹理映射技术等。得出OSG缝隙消除办法。论文针对传统的地形海量数据(基于规则格网数字高程模型)渲染对软硬件需求高、开发周期长、开发难度大等问题,提出了基于OSG的解决方案。由于OSG本身不支持Windows的图形界面,所有的操作都只能在MS-DOS方式下完成,这要涉及环境变量设置等操作。过程繁琐,也不直观。论文基于MFC和C++编写了友好的用户界面,便于层次地形模型的生成和三维地形模型的查看,使海量数据渲染在对硬件需求以及开发难度上都得到了明显的改善。随着地形可视化应用的深入,本文还介绍了一种在DEM中集成2D矢量数据的方法,通过这种方法把矢量数据缝合到DEM中,并利用MySQL来管理2D数据。更多还原

【Abstract】 3D terrain has extensive application in many fields, such as city planning, engineering design, environment supervision, disaster forecast, military affairs, games and entertainment. At present, how to realize the visualization of large scale 3D terrain based on great data is the hot topic of research, the following studies have been done around the problem.1) Interpolation and simplifying methods of Regular Square Grids. Focus on the simplifying method based on Quadtree. Summing up the process of OSG simplify .2) The pyramid data models are achieved with the data process of data division and simplization on DEM and texture data. They can provid the data model for the rendering of massive multi-resolution terrain visualization. Come to the conclusion of OSG data division and simplization.3) Study on mass data scheduling mechanism, the law of cracks, texture mapping technology. OSG approaches drawn to eliminate the gap.The traditional rendering of massive data has the features of high demand for hardware and software, long development cycle, high difficulty development and so on, and this thesis gives an effective solution for the traditional rendering of massive data, which is based on the OSG.As the OSG itself does not support Windows graphical interface, all the operations are only in MS-DOS mode to complete, which involves operations such as environment variable settings. Process cumbersome and not intuitive. Thesis based on MFC and C + + to prepare a friendly user interface, to facilitate the generation of LOD model and three-dimensional terrain model of view. For the rendering of massive data, the demand for hardware and software and the difficulty of development have been improved remarkably by taking the advantage of OSG. This paper introduces a strategy for integrating 2D data and DEM. This method sews like a sewing-machine the 2D data into DEM and use MySQL to manage 2D data .更多还原