海量地形的GIS特征数据实时渲染算法研究

Real-time Rendering Algorithm of GIS Feature Data in MassiveTerrain

研究优化管理储存海量地形信息问题,目前二维特征数据(河流,公路,区域图等)在三维地形上的可视化渲染的传统算法中,针对海量地形数据的适应方法,大地坐标系的处理以及用户对数据的交互操作缺乏完善的实现方案。为解决上述问题,提出了一种自适应的特征数据渲染算法。方法基于纹理进行数据覆盖,并自适应地根据视野范围内四叉树地块节点的LOD级别将GIS特征数据实时绘制到相应的纹理上,不仅解决了纹理覆盖方法所普遍存在的特征数据的走样和模糊问题,还可免去额外的坐标转换而直接应用到球面系统中,并且对于用户交互的特征数据绘制具有很好的自适应能力。最后,以一个使用了算法的三维地理信息管理系统为例,证明了算法在实际应用中对海量地形和用户动态绘制的特征渲染可达到预期的效果,并且配置要求低廉,具有广泛的实际应用前景。

Many problems existed in the adaptation for massive terrain data in most traditional algorithms of rendering 2D feature data（rivers,roads,area,etc.） into three-dimensional terrain,because it was too complicated,and high demanding in hardware system.This paper proposed an adaptive feature data rendering algorithm.The algorithm adopted texture-based draping,drew GIS feature data to corresponding texture adaptively,according to the current LOD level of block nodes within the field of view.This method can not only solve the aliasing and fuzzy problems of feature data in low-resolution texture,but also be applied to the spherical system without additional coordinate transformation.In addition,the method can draw interactive feature data adaptively.Finally,we took the three-dimensional geographical information management system using this algorithm as an example,the result illustrated that the practical application of the algorithm for rendering dynamic rendering of massive terrain features and interaction achieved the desired effect,and low configuration requirements.Therefore,the algorithm can provide with a widely practical application.