一个数字地形程序。主要功能有：DEM数据读取，归一化；OpenGL中为DEM添加纹理数据；OpenGL中场景漫游操作；添加3ds模型到OpenGL场景中。-A digital terrain procedures. Main functions: DEM data read, normalized OpenGL texture for the add DEM data OpenGL scene roaming in operation add 3ds model to OpenGL sce

离散点生成等高线的程序，基于方格网数字地形模型-Discrete points of the program to generate contour lines, grid-based DTM