【作者】 徐军；

【导师】 卢碧红；

【作者基本信息】 大连铁道学院 ， 交通信息工程及控制， 2002， 硕士

【摘要】 在计算机仿真中，普遍采用OpenGL建立系统的三维真实感图形，但OpenGL只提供有限的生成三维实体模型的辅助库函数，只能实现简单模型的绘制，而在虚拟现实的仿真环境中，必须建立复杂的三维实体模型。目前通过Pro／E等3D软件建立的复杂三维实体模型，均可以输出为VRML(虚拟现实建模语言)文件格式，如果在OpenGL环境能读取VRML文件，实现三维实体信息的提取与传输，就可以实现OpenGL对复杂图形的绘图与控制。为此本文开发了《基于OpenGL的VRML文件浏览器》。 《基于OpenGL的VRML文件浏览器》包括三个主要组件：语法分析器、场景图、高真感图形呈现。语法分析器读取VRML文件并将节点信息保存到图元信息中以便于场景图使用；场景图包括一个执行引擎，作用是建立显示列表，将图元信息通过列表管理，并且通过层次转换可以修改图元中的信息；高真感图形呈现主要是将处理后的图无信息呈现出来，并且根据其图元中或者用户自定义的光照、材质、纹理信息生成真实感三维图形。 该浏览器的设计采用面向对象的Visual C++语言开发。采用基于文档／视图的单文档结构，可以处理大量的三维图形数据并且解释速度快。通过使用面向对象的编程方法，便于维护管理三维数据，提高了代码的重用性。将三维图形模拟成模型进行优化设计，很好地实现了三维图形处理的数据结构设计。利用OpenGL提供的API接口，增强了构造虚拟环境的能力。 由于浏览器采用的虚拟现实建模语言，具备三维造型功能和数学建模能力，在此基础上扩展，可以适应基于网络的虚拟加工环境的开发，为异地制造奠定基础。更多还原

【Abstract】 In computer simulation, three-dimension real Graph is built by using OpenGL at large, but OpenGL only provide limited auxiliary function for generating three-dimension real solid model and only realize protraction of simple model. However, the virtual simulation environment must build complex three-dimension real model. Complex three-dimension real sculpt is mostly build by Pro/E, then export Virtual Reality Modeling Language(VRML) to realize extration and transmission.OpenGL protraction and control by reading data from vrml file. So it is necessary to design a OpenGL-based vrml file browser.OpenGL-based vrml file browser includes three main components: Parse, Scene, and Real Graph Presentation.The parse component reads the vrml file and saves the information of node as three-demension graph information and creates a Scene.The Scene component includes Execution Engine that builds displaying list and manages the three-demension information by displaying list and modifies the three-demension information by transformation Hierarchy. The Real Presentation mainly presents the graph information having been done with and generates real three-demension graph according as the graph or user-defined illumination, material, and texture information.The browser is designed by object-oriented language Visual C++ and simple document structure based on document/view, its remarkable characteristic can deal with large numbers of three-dimension graph data and have high execution speed. Maintenance and management of Three-dimension data can be realized breezily by object-oriented means. Three-dimension graph is simulated as model and optimization design. It can enhance the ablity to construct virtual object by using the OpenGL API interface.Having adopted Virtual Reality Modeling Language, the browser has the ablity to develop the three-dimension model. The browser can fit for the development of virtual manufacturining environment based on network and establish the foundation for distance manufacture.更多还原