Abstract: A simplified model of movement that snowflakes float is established based on the dynamics principle.The virtual scene that snow float is rendered based on particle system is implemented by Direct3D technologies.A simplified model of particle launchers and similar wind model are proposed so that computing speed and simulation effect are improved.Then，a method of collision detecting is put forward.Experiments show that natural result and real-time speed can be achieved by this method.And，the method can also be used to other scene simulation，such as rain，smoke，fog，and so on.

Key words: virtual snow scene, particle system, Direct3D

摘要： 基于动力学原理建立了雪花飘落的简化运动模型，并在D3D技术基础上，基于粒子系统的原理，绘制渲染了雪花纷飞的动态虚拟场景。提出了简化粒子发射器模型和碰撞检测方法，并对风力模型作了近似，在保证仿真效果的基础上提高了运算速度。实验结果表明，该方法仿真效果较好，速度快，同时能容易地推广应用到其他诸如雨、烟、雾等虚拟场景的绘制中。

关键词: 虚拟雪景, 粒子系统, 3D图形函数库