基于OpenGL的规则格网地形法线计算优化研究  

Optimization of normal calculation of regular grid terrain based on OpenGL

作　　者：韩李涛[1,2] 孔巧丽[1] 戴洪磊[1] 牟乃夏[1] 

机构地区：[1]山东科技大学测绘科学与工程学院,山东青岛266510 [2]海岛(礁)测绘技术国家测绘局重点实验室,山东青岛266510

出　　处：《测绘科学》2012年第5期17-19,共3页Science of Surveying and Mapping

基　　金：国家自然科学基金(40876051);山东省"泰山学者"建设工程专项;海岛(礁)测绘技术国家测绘局重点实验室开放基金(2009B15;2010B17)

摘　　要：本文探讨了OpenGL的光照计算原理以及法线在光照计算中的作用,针对规则格网地形的几何结构特征提出了直接计算、方程法以及迭代法计算地形平均法线的3种方法,并分析了各自的优缺点。实验证明,迭代法由于用加法代替乘法计算,同时又避免了不必要的重复法线计算,计算效率具有明显优势。Illumination calculation is the key to draw realistic terrain, and normal calculation and illumination calculation of ge- ometry elements are also closely linked. This paper discussed the principle of illumination calculation of OpenGL and the role of normal calculation in illumination calculation, proposed direct calculation method, equation method and iterative method used to calculate the average normal of terrain, and analyzed their advantages and disadvantages. Experiments showed that the iterative method has obvious advantages on computational efficiency for it uses addition instead of multiplication, meanwhile avoids unnecessary duplication of nor- mal computing.

关 键 词：规则格网 地形可视化 光照计算 法线计算 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术] P208[自动化与计算机技术—计算机科学与技术]