飞行仿真中三维云场景的渲染

云的建模和渲染是近年来计算机图形学领域的一个研究难点，在飞行视景仿真系统、计算机游戏、三维动画领域中有着广泛的应用.从建模方法、光照模型以及实时渲染3个方面对云景仿真进行研究.提出一种基于粒子系统的静态云建模方法，降低了建模的复杂度.采用云的多重散射光照模型加速了渲染速度，并且结合Impostor技术、Billboard技术实现云场景的实时漫游.仿真结果表明，生成的云层效果真实，具有良好的实时性，可在普通的PC机上流畅运行.

Cloud Rendering in Flight Simulation and Its Implementation

Modeling and rendering clouds is an important problem in virtual reality, particularly for virtual display systems, computer games, and 3D animation. This paper studies simulation of clouds, specifically the modeling method, the lighting model and rendering efficiency. Static cloud is modeled based on a particle system. This reduces complexity of the simulation. A multiple illumination model with forward scattering is then used. Billboard and impostor techniques are used to enhance speed. The result shows that visual effect of 3D cloud scene appears quite natural, which can meet the need of real time animation on a general purpose computer.