三维场景网上漫游的实时渲染技术研究与应用

【作者】 肖刚；

【导师】 王辉柏；

【作者基本信息】 北方工业大学 ， 计算机应用技术， 2011， 硕士

【摘要】 在互动娱乐、古迹重现、模拟仿真和军事演练等领域,用户对身临其境的感觉的要求越来越高。与此同时,随着硬件设备能力的逐步提升,开发者也没有停止过对真实感技术的探索和实践。三维可漫游场景的表现力和沉浸感远胜于二维的表现形式,因此近些年针对三维漫游的实时渲染技术的研究成为热点。三维场景漫游的实时渲染技术不但是三维虚拟系统的核心技术,而且直接决定着用户的真实感体验。对于三维场景漫游的实时渲染技术,本文所做的主要工作及研究如下：(1)针对大场景内物体渲染的排序问题,提出了一种基于渲染状态的渲染排序方法。首先,定义一个键值对结构,键存放的是材质信息,值存放的是物体信息。然后,解析材质脚本和物体信息并将其相应的属性填充到键(Key)的相应位。最后,分别按键的各个位所代表的意义对材质进行排序。(2)针对大规模地形的渲染问题,提出了一种基于GPU的地形LOD算法。首先,使用四叉树数据结构来组织地形数据。然后,通过GPU顶点程序处理过渡区域,消除不同细节等级层次间的裂缝问题。最后,我们将四个单通道纹理元素打包成四通道纹理元素降低了低端图形卡在顶点程序采样高度纹理的消耗。(3)针对北方工业大学虚拟校园实现过程中遇到的问题以及项目中的需求,对系统使用的场景加载策略、漫游方式、导航方式进行了介绍。最后展示了虚拟校园的部分主要功能。更多还原

【Abstract】 In the scopes of entertainment, reproducing of historical site, simulating and military affairs, the users demand the feeling of immersing themselves in the virtual scene increasingly. At the same time, with the gradual upgrading of hardware equipment capacity, the software developers never stop exploring and practicing on the realistic technology. The expressive force and immersion in 3D roaming scene are much better than those in 2D scene, so the real-time rendering of 3D roaming become hotspot recent years. The real-time rendering of 3D roaming is not only the core technology in 3D virtual System, but also determines the realism the users experience directly, In this paper, the major work and research in real-time rendering of 3D scene roaming as follows:(1)Focusing on the sorting of renderable objects in large scene, we propose a sorting method based on the rendering state. Firstly, we define a pair structure, the key is the material information and the value is the object information. And then we analyze the material script and the object information, and fill the key with the information. Finally, we sort the materials based on the meaning of each bit.(2)Focusing on the rendering of large-scale terrain, we propose a GPU based LOD approach. Firstly, we use the quadtree structure to organize the terrain data. Secondly, we deal with the transition zone to eliminate the crack between meshes in different LOD by vertex program. Finally, we package four single-channel texels to a four-channel texel to reduce the consumption of low-end graphics card in sampling heightmap in vertex program.(3)Focusing on the problems encountered and the project requirements in North China University of Technology Virtual Campus, we introduce the scene loading, roaming and navigation methods we use. Finally, demonstrates the major functions about NCUT Virtual Campus.更多还原