【作者】 刘惠惠；

【导师】 汪继文；

【作者基本信息】 安徽大学 ， 计算机技术， 2013， 硕士

【摘要】 对自然景物和模糊物体的模拟一直以来都是计算机图形学领域中一项具有挑战性的研究课题,包括对烟花、雨、雪、火、烟、雾、沙、尘等自然景物动态的模拟实现与绘制。在天气预报、宇宙航空、制作数字高清字幕、广告装潢、3D游戏等领域也有着广泛的应用。由于自然景物运动过程的随机性、表面纹理的丰富性以及表面外形的各种不规则性,使得模拟方法十分地复杂。在模拟自然景物和不规则物体的方法中粒子系统是一个很典型的方法,它能够充分的展现出自然景物的动态性质和随机性质,它的优点是对于那些传统计算机图形学都难以构造的复杂物体,可以利用比较简单的粒子元素实现它们的构造,这种方法在实时性和真实感方面都达到较高程度。粒子系统的基本原理是采用大量的微小粒子定义所要描述的对象,并在第一帧就为这些微小粒子赋予一定属性,比如位置、速度、加速度、生命周期、颜色等等；然后,随着时间的推移,粒子经历生成、活动和死亡的历程,生存期间粒子按照一定方式运动着,粒子的属性不断更新,最终形成一幅运动的图像。本论文首先描述了粒子系统的基本原理,对现有的烟花粒子系统模型进行了分析,简单阐述了现有粒子系统的优缺点；其次通过进一步研究分析烟花粒子系统的理论模型和燃放烟花的运动过程,改进了传统烟花模型的模拟,采用基于粒子系统的模拟方法,与VC++和OpenGL开发平台相结合,通过对烟花形状建模的拆分与拼接实现了0-9数字形状动态、奥运五环形状、菊花形状等形状的烟花模拟；形状烟花动态模拟的核心技术是依据高等数学理论中各种曲线方程对每个形状的每个部分进行建模,拼接每个部分的轨迹方程形成想要的烟花形状图案。随着不断更新时间和烟花粒子的运动,爆炸后生成的烟花小粒子也不断地更新着速度、颜色、大小、空间位置等属性,当烟花小粒子的生命值衰减到0或粒子运动的空间位置超出了预先设定的位置时,烟花粒子消亡,也意味着动态烟花消失；与OpenGL中的色彩混合技术、显示列表技术、纹理映射技术相结合共同处理背景,形状烟花动态模拟在真实感方面得到了提高；最后对实验结果进行分析,在夜色背景下产生的0-9数字形状烟花、奥运五环形状烟花等形态逼真,实时性能好,同时确保了安全生产、成本降低、实用性强,在烟花应用领域有着重大的意义。更多还原

【Abstract】 Simulation of fuzzy objects and nature scenery has always been a challenging research topic in the field of computer graphics, including simulation and rendering of fireworks, rain, snow, fire, smoke, fog, sand, dust and other dynamic natural scenery. In weather forecasting, aerospace, making digital high-definition title, advertisement decoration,3D games and other fields also have a wide range of applications. Due to the properties of the natural scenery, such as the randomness of the movement process, the richness of the surface texture, various irregularity of surface appearance, the simulation method is very complicated. Particle system is a typical method to simulate the irregular objects and nature scenery, it can fully show the dynamic and randomness of nature scenery. Particle system has the advantages of using a simpler particle element to construct complex objects that traditional computer graphics is difficult to construct. This method has reached a higher degree in reality and real-time.The basic principle of particle system is using many tiny particles defines the object that need to be simulated. These tiny particles are endowed with corresponding attributes at the initial moment, such as position, velocity, acceleration, life, color and so on. Then, with the passage of time, these particles experiences generation, activities and death progress, during the period of survival these particles moves in a certain way, their properties constantly update, so as to form a dynamic picture. Firstly this paper introduces the basic principle of particle system, analyses the existing firework model that based on the particle system, briefly explains the advantages and disadvantages of the existing particle system. Secondly, through further research and analysis about the theory model of particle system and the motion process of fireworks, the traditional simulation model for the fireworks has been improved. In doing so, according to the simulation method based on the particle system combined with VC++and OpenGL development platform, this paper come true the dynamic fireworks simulation of0-9digital shape, Olympic rings shape, chrysanthemum shape and so on by spliting and splicing of fireworks shape model. The key technology of shaping fireworks dynamic simulation is modeling each part of each digital parameters shape based on various curve equation in higher mathematics theory, joining together the trajectory equation of each part to form the shape pattern that we want. Along with the continuous renewal of time and fireworks particles in constant motion, it products much little firework particles with the type, color, position, shape has been changing. When firework particles’ life value decay to0or the spatial location of particle movement exceed the pre-set position, the firework particles dead, it also means that the shaping dynamic fireworks disappeared. The simulation of fireworks has improved in reality through the combination of color blending technology, display list technology, texture mapping etc in OpenGL. In the end, we analyze the experimental results:simulation of0-9digital shaping, Olympic rings shaping dynamic fireworks in the night background can create vivid images and come up to the real-time requirements. At the same time, improved the safety of production, reduced the cost of economy. It reflects the significant meaning in the fireworks technology application.更多还原