面向复杂场景的虚拟现实关键技术研究

【作者】 张翔；

【导师】 罗炳伟；

【作者基本信息】 电子科技大学 ， 生物医学工程， 2004， 硕士

【摘要】 面向复杂场景的虚拟漫游技术是虚拟现实(VR)研究的重要领域,也是信息产业应用的热点。其核心和基础是真实感图形的实时生成和绘制。传统的基于图形的绘制技术(GBR)建模复杂,图形处理过程耗时,实时交互性往往受制于场景的复杂度。近年来,基于图像的绘制方法(IBR)成为研究的热点,能获得和复杂度无关的高质量图形效果,但交互性较弱。GBR和IBR两者各有优缺点,因此基于图形建模,图像加速的混合绘制技术成为一种有效的折中,整合了IBR和GBR的优点,更具发展前景。本文详细研究了实现虚拟漫游的关键技术原理,论述了作为IBR基础的基于光场的绘制技术理论,实现了一个面向医学演示的人体器官虚拟交互系统。着重研究了基于图形和图像的混合简化绘制技术,结合几何和纹理细节层次(LOD)思想,实现了复杂场景几何模型的自动简化以及图形和图像(纹理)的实时平滑过渡,极大的降低了场景的复杂度,提高了实时交互性。论文最后提出一个面向复杂场景的虚拟漫游系统功能模型,基于Vega平台,采用图形和图像的混合简化技术,设计了高效的虚拟漫游引擎,实现了场景数据库的优化和高效动态调入,实时交互性和沉浸感良好,图像渲染效率显著提高,具有巨大的商业价值和应用前景。更多还原

【Abstract】 Virtual walkthroughs technology for complex scene is a important field of VR, which is a hot point for IT industry. The core and the base of the virtual walkthroughs is the real graphic scene’s producing and rendering. Traditional GBR involves complex modeling; more time for dealing with the graphics, besides these, the real-time and interaction are limited by the scene’s complexity. These years, IBR has become to be a hot point for research, which can get the high quality graphic effect, unrelated to the scene’s complexity yet whose interaction is poor. Because the both have their own advantage and disadvantage, the mixed rendering technology of modeling by graphics, accelerating by image is a efficient compromise, which has the virtue of IBR and GBR and will have the good future. The article studies particularly the theories for virtual walkthroughs and discusses the theory and realizes the light field rendering which is a base for IBR. Then I have designed the software about virtual interaction with the body’s apparatus using the light field rendering. The article emphasizes on the technology of mixed rendering and predilection. The algorithm can auto reduce the face number of geometric models and realize the smooth transition between graphics and image in the complex scene. At the same time, the article combine LOD thought of graphics and image (texture), which reduces the scene’s complexity greatly and improves the real-time interaction. The last of article, a virtual walkthroughs system model for complex scene is put forward. I have designed a high efficient virtual walkthroughs engine based on the VEGA, which realizes the scene data ‘s optimization and uses the method of mixed rendering based on the graphics and image and can produce the good interaction and immersion.更多还原