一种大规模地形的高效绘制算法

大规模地形的实时可视化是仿真和虚拟地理环境系统的重要问题。文章提出了一种基于规则网格的视点相关的地形模型实时生成及绘制算法。该算法采用类似于纹理多重映射的技术,以屏幕误差作为细分的依据,通过基于地形小块的自顶向下的细分来实时生成地形连续LO D模型。在PⅣ1.7G、集成显卡、256M B RAM的硬件平台上,本算法可实现对257×257个采样点地形的实时漫游.实验表明,该算法具有较低的时间、空间开销,适于大规模地形的实时可视化。

An Efficient Rendering Algorithm for Large Scale Terrain

Terrain visualization is an important problem for applications requiring accurate imagines of large datasets at high frame rates,such as simulation and virtual geographic environments.An algorithm for constructing triangle meshes is presented,which uses a very direct analogy of texture mipmapping to terrain LOD.The algorithm uses ″Block″ where each Block is a rectangular precomputed section of optimized geometry,and ″Skirts″ to fill cracks.It produces guaranteed error bounds.The algorithm execution time is proportionate to the number of triangle in the output mesh,hence it is insensitive to the resolution and extent of the input terrain.Dynamic terrain,texture mipmap,triangle strip are supported.Using the algorithm,real-time walkthrough of 257×257 terrain data is implement on the platform of PⅣ 1.7GHz,256MB RAM.Experimental results show that the efficiency of algorithm is high on both time and memory and the algorithm supports real-time visualization of large scale terrain.