LOL：一种大规模虚拟环境中动态多层次光照表示和处理方法

摘要

在范围广泛、包含大量复杂物体的大规模虚拟环境中，设置一定数量、多种类型、甚至可以移动的光源，系统实时性能必然会由于计算开销的增加而降低.提出了一种大规模虚拟环境中动态多层次的光照表示和处理方法LOL(levelof light).它提出了一个新的概念——光照层次(LOL)，并给出了在不同的时间和空间中，相邻光照层次LOL之间的切换机制，同时采用四叉树管理光照影响范围内的动态几何对象.实验结果表明，在大规模的虚拟环境中应用LOL方法处理多水平层次的光照效果，能够较大幅度地减少系统的计算开销，在一定程度上缓解了虚拟环境的逼真性与系统运行的实时性之间的矛盾.%A new dynamic multilevel light method for generating realisticilluminating effects in a large-scale virtual environment is presented. This new method allows each illuminant have several levels of light, such as point light, local light, spotlight, entirely environmental light, and so on. According to the requirements of simulation, the illuminant uses tunable parameters to select a more economical level of light from all its levels in some time during the simulation. This new method also utilizes quadtrees to fleetly find objects illuminated by certain level of light, to load correct models at multiple LOD, and to calculate the critical values.