【作者】 赵春艳；

【导师】 钟绍春；

【作者基本信息】 东北师范大学 ， 计算机软件与理论， 2010， 硕士

【摘要】 植物是自然界最重要的组成部分之一,与人类的生存与生活密切相关。所谓虚拟植物(Virtual Plant),就是利用计算机来模拟植物在三维空间中的生长发育过程,以可视化的方式来反映植物的形态结构规律。虚拟植物的研究是虚拟现实(Virtual Reality)技术中复杂耗时且最关键的技术之一,目前已经成为研究热点,在农业、林业、教育、娱乐、商业等领域有着广阔的应用前景。各种常用的植物建模方法都不是普适的,建模效率与建模结果的真实感之间难以平衡。另外,目前针对各种高大树木以及小麦、大豆、玉米、棉花、水稻等主要农作物的建模方法研究较多,而针对向日葵的研究报道还很少见。因此,本文主要以向日葵为研究对象,探讨如何快速有效地进行植物生长模型构建,根据自然界中真实向日葵的形态结构特点与植物学研究者测量的相关数据以及相关理论基础,对向日葵植株的地上部分进行了生长模型的构建。具体工作主要体现在以下几个方面:(1)针对向日葵地上部分主要器官(茎、叶、花)各自的不同特点,采用合适的方法分别对其进行几何模型的构建,以实现通过少量的人机交互达到较为逼真的模拟效果。提出了用参数化方法控制向日葵叶片的大致轮廓,并在此基础之上通过简单的计算修正轮廓,从而生成锯齿状叶缘的方法。(2)建立向日葵各器官的动态生长模型,实现向日葵各器官形态随时间的动态变化过程。其中,对传统的L-系统进行改进,并用于向日葵花开过程模拟和叶脉的拓扑结构构建,提高了效率,且节省了存储空间;基于形态特征变化对向日葵的向光性运动进行了模拟。(3)基于中国科技大学的赵星博士提出的双尺度自动机模型,以及“生长延时”机制,结合向日葵的具体特征,调用各器官的生长模型,进行向日葵植株的拼接,构建出向日葵植株不断变化的拓扑结构,实现了向日葵植株的动态生长过程。(4)以中小学生物实验课课堂教学为目的,利用面向对象(Objected Oriented)的思想设计了交互式向日葵虚拟生长系统,并采用MFC+OpenGL的组合方式在Visual Studio 2008集成开发环境下进行系统开发,将向日葵的动态生长发育过程可视化,充分验证了本文论述的解决方案的有效性,并具有一定的实际应用价值。更多还原

【Abstract】 Plants were the most important and general life forms in the nature, and were very close to our daily lives. Virtual Plant was an interesting subject that simulates the growth process of the plants in 3-dimension space in computer, and reflects the morphological architecture rules of the plants. It was one of the most time-consuming, complex and pivotal technologies, belonging to the Virtual Reality. Virtual Plant had become one of the focuses in the Computer Science area, and opened up a vast range of application area, including agriculture, forest, education, entertainment, business and so on.The common plant construct methods were not suitable for all kinds of plants. And it was difficult to balance the efficiency and the quality. Additionaylly, there had been a lot of papers talked over the model of trees, wheat, soybean, corn, cotton, rice, etc. But few or nothing was about sunflower. So the paper aimed at the sunflower, but not the general plant. According to the sunflower’s topological structures and the data got by the researchers on the botany, this article visualized the growth of the whole plant, except the root. The main research and achievements were as follows:(1) Analyzed the special character of the sunflower organs, summarized various modeling methods, and selected the suitable method to construct the geometry model of the organs. A method which helps to gain a delicate sketch of the leaf from a rough one is proposed.(2) Simulated the dynamic growth process, including the movement process of the stem following the sun, of the organs by suitable growth function and reasonable assumption. The traditional L-System was improved for greater efficiency and less memory space, and successfully used in the visualization of the flower and skeleton of the leaf.(3) Set up the growth model of the sunflower based on the Dual-Scale Automation Model proposed by Dr. Xing-Zhao of CUST.(4) Designed the Sunflower Growing Simulation and Visualization System , which was aimed at the biological laboratory courses of the middle and primary schools. So the validity of the solution was fully verified. At the same time, the system could be widely used to prove the traditional teaching method.更多还原