摘要
本文在吸取了计算机图形学、现代数学、测绘学等众多领域大量先进理论成果的基础上，研究了地形建模的基本理论和方法基于高度图的地形显示技术.文章分析了基于高度图的均匀网格地形渲染算法，给出了具体实现并提出了有效的改进方法。该算法顶点数组来提高对均匀网格的渲染效率；在多细节层次算法中增加了地形边缘的细节层次，使地形轮廓更为清楚。指出图形生成是虚拟现实的关键问题并综述了图形生成的技术；随后回顾了地形显示及实时显示技术和方法。在此基础上通过在位图的灰度值与地形高程之间建立映射关系，快速生成了三维网格地形．以生成具有高度真实感的三维地形。
关键词：三维地形；三维图形；地形建模；地形模型；灰度等级；三维地形模拟

Abstract
      This thesis absorbing the computer graphics, the modern mathematics, the surveying and mapping and other advanced theory achievements, has studied the terrain modeling elementary theory and the method. This thesis analyzes the uniformity of the height map terrain rendering algorithms, and put forward the effective improvement methods. By improving the efficiency of rendering uniform grid and adding the edge of the level of detail   terrain . The terrain contours become clearer. This thesis points it out that the generation of a virtual reality graphics is the key issues, and reviews the resulting graph technology and subsequently, reviews the terrain generation and real-time display technology and methods. Based on that, the thesis makes the reflect relationship between Height Chart and Terrain elevation. Eventually, a three-dimensional grid terrain has been mapped rapidly and then produced a highly realistic three-dimensional terrain.
Key words：：3D terrain ；3D graph；terain modeling；terrain model；gray level；3Dterain simulating
目录
摘要 1
Abstract 1
1 绪论 2
1.1 研究的前景和意义 2
1.2 国内外研究现状 2
1.2  本文研究的内容 3
2 基于osgEarth＋MFC的建模基础 4
2.1 osgEarth概述 4
2.2 osgEarth渲染管道 5
2.2.1 显示列表 5
2.2.2 求值器 5
2.2.3 基于顶点的操作 5
2.2.4 图元装配 5
2.2.5 像素操作 6
2.2.6 纹理装配 6
2.2.7 光棚化 6
2.2.8 片断操作 6
2.3 MFC概述 6
2.3.1 封装 7
2.3.2 继承 7
2.3.3 虚拟函数和动态约束 8
2.3.4 MFC的宏观框架体系 8
2.4 MFC编程框架 8
2.5 基于osgEarth+MFC的三维模拟的编程环境配置 11
3 基于高度图的地形显示 15
3.1 由一幅高度图生成地形的原理、关键算法 15
4 系统的设计及实现 17
4.1 系统的实现的原理、关键技术 17
4.2 系统中高度图的读取、纹理映射 18
4.3 系统的设计 18
4.4 实验结果（屏幕截图） 20
5 结论与展望 23
5.1 结论 23
5.2 展望 23
致谢 24
参考文献 25