中文摘要：

在分析已有的降雪和积雪模拟方法的基础上，提出了一种大场景环境下降雪和积雪模拟的新方法。将降雪和积雪过程看成雪景模拟的两个阶段，分别用不同的方法进行模拟。在降雪方面，引入粒子的旋转，粒子动态纹理和动态颜色等，提高了降雪模拟的真实性和灵活性；在积雪方面，引入噪声技术，解决了已有积雪模拟方法不能用于大场景模拟的问题。实验表明，降雪积雪模拟方法模拟效果真实，实时性良好，适合大场景尤其是飞行模拟系统中。

英文摘要：

Based on the analysis of traditional simulation methods, this paper presents a new approach for simulation of snow falling and accumulating in large-scale terrain. The snow simulation is divided into two stages-falling and accumulating. In the former stage, rotation, dynamic texture, and dynamic color of particles are taken into account, which greatly improves the reality of simulation. In the later stage, image noise is introduced to a large-scale terrain, which solves the problem that the traditional methods cannot be scaled up to the large-scale terrain. Experiment shows this method improves the in snow simulation, keeps real-time, and adapts to the large-scale terrain, especially for the scene with flight simulation.