数字地貌晕渲光照模型研究

Research on Illumination Model of Digital Relief Shading

光照模型是地貌晕渲图能够在2维平面获得地貌3维立体形态的主要原因。在计算机图形学的基础上,推导了基于数字高程模型的晕渲光照模型计算公式;通过对相关文献公式的分析,指出了数字地貌晕渲采用的光照模型与传统地貌晕渲几何光学原理的关系;并对该模型下地表灰度值的计算与变化进行了分析研究。

Illumination model is the main reason of shaded relief map which can get 3D image on 2D map. Based on computer graphics, the illumination model formula on digital elevation model was calculated. Through ana- lyzed the formulas of correlative literature, the relation of illumination model of digital relief shading and the geometry optics principle of tradition relief shading was pointed out. The calculation and change of terrain gray value under this illumination model were researched.