煤层顶底板DEM二维光照渲染制图方法

煤层顶底板等高线图是煤矿企业用于生产决策的一种常用图纸,这种图的直观性较差,难以阅读。参照Tanaka明暗等值线图的方法提出一种基于二维显示的煤层底板DEM的光照渲染制图方法。该方法通过假定光源所处的位置,并计算DEM的三角面片的法向,进而求得三角面片的亮度,然后以填充绘制的方式将所有三角形以二维的方式绘制出来。这种方法具有显示效率高、编程简单、易于图层叠加、效果较Tanaka法逼真等优势。

A 2-D light-shading mapping method for DEM map of coal-floor

Coal-floor contour maps are fundamental to coal mineral companies,but their visual effects are very bad so it is not easy for people to read.The author of this article proposes a method that can produce light-shading maps based on 2-D DEM.The key technique of this method that assumes the location or orientation of the light,and then calculates the normal vector and lightness of every triangle facet in DEM,and finally draws all triangle-facets by filling them with the color just is calculated.This method has high efficiency of drawing maps,easy programming,easy overlays of map layers,and is better than Tanaka method.