Abstract: Based on the analysis of the existing simulation method of snowfall and accumulated snow, this paper proposes a new way of setting the particle attribute. The snowfall process is optimized. It simulates the snow on the shady side of a building under the condition of the relatively stable wind innovatively, using the principle of the shadows. It takes snowfall and accumulated snow as two independent stages, using different methods to simulate respectively. Snowfall aspect, mainly adopts particle system, adding texture style as the attribute, and using the optimization techniques such as display list to improve rendering efficiency significantly. Accumulated snow aspect, introduces technology of noise, and connecting with the multistage particle system, recreates the state of no accumulated snow on the shady side of real life situations. Experiments show that the simulation effect is clear, with good real-time performance, suitable for application in the need for real-time rendering of virtual environments.

Key words: particle system, noise technology, snowfall, optimization, accumulated snow on the shady side, shadow

摘要： 在分析现有的降雪和积雪模拟方法的基础上，提出了一种新的粒子属性设置方式，对降雪过程的绘制速度进行了优化，并且创新性地运用阴影形成原理，模拟了风力较为稳定的条件下，建筑物背阴处的积雪情况。将降雪和积雪过程看成是两个独立的阶段，分别采用不同的方法进行模拟。降雪方面，主要是采用了粒子系统，为粒子添加了纹理样式这一属性，并运用了显示列表等优化技术，使得绘制效率得到了显著提高；积雪方面，引入噪声技术，并结合多级粒子系统，再现了现实生活中背阴处无积雪的情况。实验表明，模拟方法效果逼真，实时性良好，适合应用于需要进行实时渲染的虚拟环境。

关键词: 粒子系统, 噪声技术, 降雪, 优化, 背阴处积雪, 阴影