虚拟环境中基于能见度的多精度烟尘生成方法

A Method of Generating Multi-resolution Smoke Based on the Obscured Visibility in Virtual Environment

虚拟环境中生成的烟尘效果 ,不但要使用户获取逼真的视觉感知 ,而且要根据烟尘的特性 ,计算烟尘对虚拟环境中用户或仿真实体的能见度的影响 .但是花费大量的系统资源生成精确的三维烟尘 ,并计算烟尘对虚拟环境能见度的影响 ,必然会导致系统实时性的急剧下降 .根据高斯型的烟尘表示 ,该文提出了一种基于虚拟环境能见度的多精度烟尘生成方法 .在生成各种近似烟尘的过程中 ,该方法给出了一种新的烟尘释放与烟尘合并方法 ,来控制近似烟尘的精度和数量 ,从而减少对系统实时性能的影响 .同时给出了一种权衡烟尘精度与系统实时性能的机制 ,即根据实验平台的计算能力和虚拟环境能见度的要求 ,生成该平台中对实时性能影响较小、具有一定精度的近似烟尘 。

The smoke puff in virtual environment can not only make the user have realistic vision apperceive, but also affect user's visibility and operations. Considering the expensive computation for smoke puff, the methods of generating multi resolution smoke have been studied, since smoke is required by different experimental platforms and has the ability to obscure the visibility in virtual environment. Because usually smoke moves slowly, which is sent out continuously from something burning in virtual environment, the comparability can be found after the comparison between the smoke puff in one of short time intervals and others. According to Gaussian puffs model, this paper presents a new method of generating multi resolution smoke puffs based on obscured visibility in virtual environment. With the average of smoke density in one time interval, it includes smoke emission, smoke merge, and light transmission through smoke cloud while generating multi resolution smoke. At the same time, it also gives a way to tradeoff smoke resolution and performance according to requirements and computational capabilities of experimental platform, and to estimate the reliability of experiment results.