基于OSG的三维GIS地形与矢量数据的渲染系统的设计与实现

发布时间：2018-05-15 09:47

本文选题：三维GIS + 地形　；参考：《成都理工大学》2013年硕士论文

【摘要】：目前，三维GIS的一个重要特点是地形数据量巨大，，漫游局部高分辨率的地形时，几何体顶点的数量可高达上百万个，普通计算机的硬件无法将它们全部渲染出来；传统的二维矢量数据模型是GIS中一种重要的数据模型和数据源，随着信息技术的发展，人们要求地理空间矢量数据与地形完美匹配，同时发挥地形与GIS矢量数据的优点。要实现这个目标，首先要解决的问题是如何组织管理并实时渲染空间数据，本文使用OSG作为场景管理工具解决这个问题，重点在如下几个方面展开了研究：（1）本文研究了构建数字地形的重要数据来源：数字地形模型。对目前三种主要的DEM类型的概念、数据结构和特点进行探索，最后根据本研究的目的选择规则格网DEM作为本研究的数据来源之一。然后探讨了OSG的相关项目中的三维地形的组织方式：层次细节模型和金字塔模型的文件存储方式以及遥感影像纹理的多层次贴图技术，最后探讨了OSG中模型数据的动态调度机制；（2）本文对二维GIS的矢量数据文件格式（Shapefile）进行了深入研究，以寻求转换为OSG场景模型的切入点，分析了矢量数据与地形结合渲染的技术路线；然后将矢量数据转换为OSG场景模型的过程分解为多个环节处理，对每个环节的任务进行了详细地介绍；（3）本文基于OSG开发了一个小型的三维GIS渲染系统，以研究在不同硬件平台下的地形和矢量数据的实时渲染能力。首先设计本系统的体系结构、分析了功能模块、并给出软件框架结构；接着对不同的功能模块的实现方法进行了研究分析；还研究了本系统中关于矢量数据处理和场景操作的多线程工作机制；（4）本文最后对不同三种图层编译方式进行了比较分析，并对地形与矢量相结合的渲染性能进行分析，系统运行结果表明，基于OSG的海量地形和矢量数据的解决方案，能够实现海量地形和矢量数据的实时渲染。
[Abstract]:At present, one of the important characteristics of 3D GIS is the huge amount of terrain data. When roaming the terrain with high resolution, the number of geometric vertices can be as high as one million, and the hardware of ordinary computer can not render them all. The traditional two-dimensional vector data model is an important data model and data source in GIS. With the development of information technology, people require the perfect matching of geographical space vector data and terrain, and at the same time give play to the advantages of terrain and GIS vector data. To achieve this goal, the first problem to be solved is how to organize, manage and render spatial data in real time. This paper uses OSG as a scene management tool to solve this problem, focusing on the following aspects: 1) this paper studies the important data source of constructing digital terrain: digital terrain model. This paper explores the concept, data structure and characteristics of the three main types of DEM, and finally selects the regular grid DEM as one of the data sources of this study according to the purpose of this study. Then it discusses the organization of 3D terrain in the related projects of OSG: the file storage method of hierarchical detail model and pyramid model, and the multi-level mapping technology of remote sensing image texture. Finally, the dynamic scheduling mechanism of model data in OSG is discussed. In this paper, the vector data file format of 2-D GIS is studied in order to find the breakthrough point to transform it into OSG scene model, and analyze the technical route of the combination of vector data and terrain rendering. Then the process of transforming vector data into OSG scene model is decomposed into several links, and the tasks of each link are introduced in detail. In this paper, a small 3D GIS rendering system based on OSG is developed to study the real-time rendering capability of terrain and vector data on different hardware platforms. Firstly, the architecture of the system is designed, the function module is analyzed, and the software frame structure is given, then the realization methods of different functional modules are studied and analyzed. The multi-thread working mechanism about vector data processing and scene operation in this system is also studied. Finally, this paper makes a comparative analysis of three different layer compilation methods, and analyzes the rendering performance of the combination of terrain and vector. The system running results show that the solution of massive terrain and vector data based on OSG. The real-time rendering of massive terrain and vector data can be realized.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208

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