基于三角形带的地形可视化算法研究

Research on Triangle-strip-based Terrain Visualization

三维地形可视化是三维视景仿真的重要组成部分。目前多数地形LOD算法以地形本身的数据结构为出发点,在绘制过程中地形网格中的三角形一般作为独立的元素在图形加速卡中演染,在一定程度上降低了效率。对基于三角形带的地形可视化算法深入研究,首先使用交叉存取的四叉树数据结构对网格进行表示,表示方法有利于在显示过程中实时产生三角形带,通过嵌套误差判据球来确定顶点的活跃度,最后所产生的地形网格是一个三角形带,有利于加快显卡的处理速度,提高了显示效率。实验结果表明,算法是可行的。

Terrain visualization is an important part of scene visualization. For most of currently used terrain LOD algorithms, terrain structure determines their data structures used, and the triangles in the resulted terrain mesh are usually rendered as individual elements in graphics cards, which will reduce the efficiency in certain degree. In this paper, an algorithm based on triangle strip is studied. Interleaved quadtree structure is employed for mesh representation, which will make the process of triangle mesh generation much easier. Nested error metric sphere is used to determine the activities of vertices and the resulted terrain mesh is in the form of a single triangle strip, which can be sent to graphics card in a single operation and improve the display efficiency. The result proves its feasibility.