三维真实感图形是科学可视化、计算机动画、虚拟现实的技术核心，也是时空一体化地理信息系统的关键技术，而OpenGL又是目前最新的三维图形国际标准，为了实现地形的真实感显示，讨论了三维真实感地形表现在OpenGL支持下的地形模型映、遥感影象与地形的融合、专题信息与地形的融合、以及动画与虚拟现实等技术实现方法，并在荆江分洪区洪水演进模拟系统等开发中得到应用。

A 3D realistic image is a core technique of scientific visualization, computer animation, and virtual reality, and an important technique of spatio temporal GIS. OpenGL is the current international standard of 3D image. This article discussed the implementing method for the representation of terrain realistic image based on OpenGL, such as the digital terrain model mapping, the blend of remote sensing image and terrain data, the blend of thematic information and terrain data, animation, virtual reality, and etc.The mapping methods respective to the DTM format such as TIN, GRID and Contour, the direct and indirect blending methods of remote sensing image and terrain data, and the blending method of thematic information and terrain data based on the 2D transparent texture were presented mainly. Based on aforementioned methods, a flood routing visualization system for Jingjing diversion area was developed and the results fit the anticipant goals well.