基于osgearth局部等高线画法研究及实现

Research and Implementation of Local Contour Based on Osgearth

针对在地理信息系统上绘制等高线时常常需要将全部高程数据读入缓存,造成三维等高线渲染速度慢、绘制效率低的问题,本文提出了一种由用户鼠标选定关心区域,根据用户指定采样行数、采样列数和等高线间距等参数,高效、快速地在osgearth平台上绘制三维等高线的一种画法及实现。并将局部等高线做成插件,方便系统集成,其中的二维等值线算法也适用于计算二维等值面其他问题地实现。

For drawing the contour lines in the geographic information system often needs to be all the elevation data into the cache,resulting in slow rendering, 3 D contour rendering problems of low efficiency, this paper proposes a mouse by the user selected re-gions of interest, according to user specified sampling number of rows, columns and contour sampling spacing, and achieve a draw-ing efficiently and quickly rendering 3 D contour on the osgearth platform. In addition, the local contour line is made into a plug-into facilitate the integration of the system, and the two dimensional contour algorithm is also applied to the realization of other prob-lems of the two-dimensional ISO surface.