【作者】 莫燕；

【导师】 罗会信；

【作者基本信息】 武汉科技大学 ， 机械电子工程， 2003， 硕士

【摘要】 虚拟现实技术在近年来得到迅速发展，已经与多媒体技术及计算机网络技术并称为现代三大计算机技术。 本文介绍了虚拟现实的概念，虚拟现实系统所具有的基本特点，以及虚拟现实的关键技术和研究内容。通过深入系统地分析虚拟现实技术在国内外的研究现状和发展趋势，提出本课题的研究工作重点是建立三维模型系统，实现三维几何实体模型的调入、显示及交互。在不影响模型显示质量的前提下，对其进行静态和动态的简化处理，以减小绘制过程所需的计算机资源，提高交互的实时性，为充分利用低档计算机尤其是PC机来实现虚拟现实系统开辟一条新的途径。 模型构造是虚拟现实技术中最基本的也是必不可少的一项技术，Windows包含的OpenGL是目前国际上公认的三维图形工业标准，但是复杂的物体模型不可能单纯依赖于利用OpenGL基本函数以及实例库提供的基本几何体来构造，而且建立三维模型库不仅工作量巨大，应用程序也不具有普遍适用性。本文中以面向对象语言VC++实现了OpenGL与3DS文件之间的接口，可以直接显示3DS模型。充分利用丰富的3DS公共资源，来降低虚拟现实系统的开发难度。 如何充分利用PC机来处理复杂的几何模型，是近几年的热门话题。特别是虚拟现实技术的发展，对复杂模型的实时动态显示提出了更为迫切的要求。本论文中提出以顶点的法向变化情况来控制简化误差的算法在简单性、简化速率和简化质量方面均取得了较好的效果。静态简化模型以20％简化率在最大程度上保持了模型的细节绘制特征。以静态简化模型为基础，将模型的绘制与视点的变化关联起来建立多分辨率显示模型，在模型覆盖象素越来越少的情况下可以达到80％的简化率，而且交互操作过程能够达到实时性的要求，不会让用户感到有明显的延时。 本系统以OpenGL作为研究虚拟现实的工具，实现了三维模型的调入、显示及交互的集成，对虚拟现实系统底层平台的开发作了初步的探讨。随着研究的不断深入和发展，本系统将逐步完善，体现出巨大的实用价值。更多还原

【Abstract】 Virtual reality technique is getting the quick development in recent years, having been combined with multi-media technique and computer network technique to call the modern three greatest computer techniques.This paper discusses the basic concepts, primary characteristic, pivotal technologies and research content of virtual reality. By analyzing studying actuality and developing tendency of VR, this paper puts importance on how to set up a 3D model system, so as to realizing loading, rendering and interacting of 3D model. Under the precondition of showing model without affecting its precision, model has been handled with static and dynamic simplification, to cut down computer resources for needing in the process of rendering, advancing real-time interaction. It is developed a new path to realize VR system, for making use of the low class computer especially for PC.Model rendering is the most basic and integrant technique within VR technologies. OpenGL that belongs to Windows is recognized as the industry standard of 3D model, but it is impossible to render complicated mo’dels only depending on basic functions and samples of OpenGL. Constructing a 3Dmodel bank has great workload, and the program also has not the widespread applicability. This paper gets an interface between OpenGL and 3DS files by 00 VC++, which can be used to display 3Dmodel directly, so as to making full use of abundant public 3D resources and reducing difficulty of developing VR system.How to make use of PC to handle complicated geometry model, is the hot issue in the last few years. And developing of VR technology brings more exigent requests for real-time rendering of complicated models. In this paper, the algorithm in which normal vector of vertex is used to control simplifying error obtains good result on briefness, simplifying velocity and quality. Static simplifying model keeps the rendering character in detail to a great extent by 20% simplification. With static simplifying model as basic model, it is to set up Multi-resolution model that model rendering is relatedto changing of observe point. With covering with less and less pixels, model can be handle to 80% simplification, and process of interaction can reach to real-time request, not making user feel obvious delay.By using OpenGL as tool to research into virtual reality, this system realizes loading, rendering and interacting of 3D model and gets some achievement on the development of bottom VR system flat-form. With further research, this system will become more and more perfect, and will bring tremendous applied benefit.更多还原