Abstract: In this paper，a soft shadow algorithm based on ray-tracing was introduced.The effect of the shadow seemed more vivid.It also overcame the problem of distortion based on shadow mapping.Experiments demonstrate that this algorithm can also produce visually pleasing effect for the complex objects，so that the algorithm can satisfy the requirement of the virtual reality application.

Key words: ray-tracing, soft shadow, area light source

摘要： 提出了一种基于光线跟踪的软阴影算法。该算法生成的阴影更具真实感，并可克服阴影映射算法产生的锯齿现象的问题。实验结果表明，该算法对较复杂物体仍能够保证良好的绘制视觉效果，满足虚拟现实应用的要求。

关键词: 光线跟踪, 软阴影, 面积光源