【摘要】 虚拟地形环境在游戏、仿真、虚拟现实等领域有广泛的应用,在网络环境下如何进行海量地形数据的三维表达与传输是目前研究的重点。基于对等思想提出一种适合大规模地形漫游的分布式网络结构,充分发挥客户机的作用,从而有效地减少服务器负载,采用多点下载数据,提高地形数据的传输速度。同时研究该网络结构下多点下载模型、数据预处理、数据流程和视点相关的LOD简化算法,实现网络环境下大规模地形实时漫游。实验结果表明,在分布式网络环境下,该文中提出的方案可实现大规模地形实时漫游。更多还原

【Abstract】 Large-scale terrain walkthrough has been widely used in games,simulation,virtual reality,etc.It is very important for large-scale terrain data to visualization display and network transmit under web-based distributed environment.This paper firstly proposes a distributed network architecture that can adapt to real-time rendering of large-scale terrain under web-based distributed environment.The architecture aims to use full client’s effect,reduce server’s load,download data from multi data sources and improve transmission speed of terrain data in network.Meantime some key techniques,including user node organization and management,data resources registration and search and failure recovery,are also been studied to ensure effectively data transmit in the distributed system.Then a kind of quad-tree structure is adopted to organize terrain dataset and terrain data is divided into different layers and blocks in order to build up different multi-resolutions data layers in which each layer stands for a kind of resolution.A view-dependent refinement algorithm for continuous LOD and data flowchart of terrain visualization in client are also discussed in order to simplify terrain scene and improve the rendering efficiency.Finally,a prototype system is established and experimental results show that the paper’s method is efficient in large-scale terrain walkthrough under web-based distributed environment.This method does not restrict amount of clients,and will become more efficiency if more clients join.更多还原