中文摘要：

全球照明效果为虚拟植物显示是关键的。而即时全球照明显示植物是不切实际的，周围的吸藏是有效其他的近似。有百万个三角形的一个树模型是普通的，并且当随机散布了，三角形能被考虑。存在周围的吸藏方法没能在如此的一种类型上适用反对。在这篇论文，我们在场奉献给实时植物与有限用户交互作用显示的一个新周围的吸藏方法。这个方法是对在空格随机散布的几何学对象的一个巨大的数字合适的一个三步的周围的吸藏计算框架。建议算法的复杂性是 O (n) ，与有 O 的复杂性的常规方法相比(n 2 ) 。而且，在这个方法的参数能容易被适应完成灵活周围的吸藏效果。与这个周围的吸藏计算方法，我们能与百万个机关操作工厂模型，以及几何学与买得起的时间，并且与比得上以前的周围的吸藏方法的感性的质量与随机分布式的部件的大数字反对。电子增补材料这篇文章(doi:10.1007/s11390-007-9104-9 ) 的联机版本包含增补材料，它对授权用户可得到。

英文摘要：

Global illumination effects are crucial for virtual plant rendering. Whereas real-time global illumination rendering of plants is impractical, ambient occlusion is an efficient alternative approximation. A tree model with millions of triangles is common, and the triangles can be considered as randomly distributed. The existing ambient occlusion methods fail to apply on such a type of object. In this paper, we present a new ambient occlusion method dedicated to real time plant rendering with limited user interaction. This method is a three-step ambient occlusion calculation framework which is suitable for a huge number of geometry objects distributed randomly in space. The complexity of the proposed algorithm is O（n）, compared to the conventional methods with complexities of O（n^2）. Furthermore, parameters in this method can be easily adjusted to achieve flexible ambient occlusion effects. With this ambient occlusion calculation method, we can manipulate plant models with millions of organs, as well as geometry objects with large number of randomly distributed components with affordable time, and with perceptual quality comparable to the previous ambient occlusion methods.