Abstract: Tree modeling and simulation has always been a challenging research topic in WebVR due to its complex structure and a great amount of data. Especially nowadays with the expansion of 3D virtual scene in web, the contradiction is more prominent between the real-time downloading request of mass virtual forest from client and the limiting network bandwidth. This paper proposes a rule-based method which can help to construct lightweight Web3D forest. This method is based on L-system’s self-similarity and the reuse thinking in WebVR. It can change tree/forest model files to lightweight Web3D files successfully, even only a few kB size. The virtual scene is also suitable for online real-time transmission and browsing in low web bandwidth environment. To a certain extent, the bottleneck problem is solved.

Key words: Web Virtual Reality（WebVR）, tree modeling, rule-based modeling, lightweight, L-system

摘要： 树木的建模仿真因其结构十分复杂数据量巨大一直以来都是WebVR领域中极具挑战的研究课题。尤其是目前随着网上三维虚拟场景的急剧扩张，海量WebVR虚拟森林场景在用户端的实时下载请求和有限网络带宽之间的矛盾亦变得日趋突出。提出了基于L-system的Web3D虚拟树木语森林的轻量化建模方法，基于树木L-System描述体系的自相似性和基于重用的WebVR轻量化建模思想，成功地将虚拟树木/森林场景转化为极为轻量化的Web3D文件，甚至只有十几kB大小，即便网络带宽很低的情况下，也非常适于网上的实时传输与漫游，在一定程度上解决了该瓶颈问题。

关键词: 基于网页的虚拟现实, 树木建模, 基于规则的建模, 轻量化建模, L系统