【作者】 辛玲；

【导师】 童小念；

【作者基本信息】 中南民族大学 ， 计算机应用技术， 2008， 硕士

【摘要】 在虚拟仿真场景中,喷泉、火焰、水流、雨、雪等景物具有不规则几何状态、动态性和随机性,这些特殊景观的模型比较复杂,实时播放中的运算量较大。为了保证视景仿真的实时性,对特殊景观的建模一直是视景仿真领域和计算机图形学领域中研究的热点。粒子系统是实现动态不规则景物模糊效果的有效方法,它使用大量粒子的聚集灵活地构成特效景物,用简单的粒子图元构造出传统计算机图形学难以构造的复杂模糊物体,具有很强的真实感,能够很好地体现景物的动态性和沉浸感。粒子系统是虚拟现实技术中的主要研究内容之一。鉴于粒子系统建模的灵活性和有效性,本文研究了粒子系统的基本原理及应用,探讨了粒子系统的建模方法以及适用于自然景物动态模拟的粒子属性的通用描述公式,并选取自然景物中的特效景观作为动态模糊物体代表,以OpenGL三维图形函数库作为绘图工具,在VC++的开发环境下对不规则的、模糊的、动态的自然景观进行了模拟,最后利用Vega的回调函数及融合技术,将OpenGL编程实现的特殊景观移植到虚拟现实的Vega环境中,实现了一个基于粒子系统的虚拟自然景观实例。本文的创新点在于结合牛顿重力学的基本理论,对特效景物提出了简化的粒子系统力学模型,旨在降低粒子系统的计算量,保证特效景物在视景仿真中的实时性能。视景仿真的实验结果表明,本文建立的粒子系统算法具有较强的有效性和实时性,采用粒子系统算法对特效景观建模,具有灵活性和高效率,其自然景观的模型在虚拟仿真环境下展现了实时逼真的三维效果。更多还原

【Abstract】 In the virtual simulation scene, the natural sceneries such as fountain, fire, water-stream, rain and snow have anomalistic, dynamic and stochastic features. The special landscape model is more complicated, and needs a large number of computing in real-time player. In order to ensure the real-time characteristic of visual simulation, modeling of special landscape has been a hotspot in the field of visual simulation and computer graphics research.Particle system is an effective method for representing fuzzy effect of dynamic and anomalistic objects of nature. It gathers a large number of particles to affect a scene flexibly. It structures the complex fuzzy objects which are difficult to construct in traditional computer graphics by simple particle elements. It can also reflect the dynamics and immersion of the sceneries with highly reality. Particle system is one of the main research content in the virtual technology of reality.In view of the particle system modeling flexibility and effectiveness, the paper studies the basic theories and applications of the particle system,and discusses method of modeling and the common formula of the particle attributes which go for the scene dynamic simulation. Then, the paper chooses the special landscape to simulate the anomalistic, fuzzy and dynamic characteristic under VC++ by the OpenGL function. Finally, the paper transplants the special landscape which realizes by the OpenGL to the virtual reality by the callback function and fusion of Vega. It realizes an example of virtual landscape based on particle system.In the paper, a new idea is using Newtonian to simplify particle model. It guarantees the real-time characteristics of the special sceneries of better effect during the virtual simulation.The experimental result of visual simulation shows that the particle system algorithm is more effective, and modeling special landscape produced by the particle system algorithm is more flexible and efficient. The model of the special sceneries of better effect can produce the vivid effect of three-dimensions in virtual simulation.更多还原