虚拟园林景观中植物茎叶器官的交互可视化表达方法研究

项目名称： 虚拟园林景观中植物茎叶器官的交互可视化表达方法研究

项目编号： No.30872066

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 淮永建

作者单位： 北京林业大学

项目金额： 30万元

中文摘要： 本课题对虚拟植物的形态结构可视化建模和大规模植物群落的实时绘制技术进行了深入研究，提出或改进了植物单体和群体的结构建模和绘制算法。对植物组织器官(主干、茎枝、叶和花等)形态结构特征进行了研究，研究了参数化的植物形态表达规则，提出了一种基于L~系统的虚拟植物拓扑结构的通用化表达方法。基于树木叶片组织器官的表面特征细节（叶脉、纹理、骨架等），研究了高度真实感的植物叶脉纹理生成、叶片形变和叶序模拟方法，提出了一种基于改进的DLA生长素凝聚的叶脉骨架生成方法和基于骨架特征点的三维光滑形变技术。研究了植物花瓣器官的图像特征，基于真实的图像特征数据和花瓣层叠方法，建立了重瓣花卉的曲面建模和花序表达方法。研究了真实感的植物器官和大规模植物群落（树木森林）的实时绘制技术，基于LOD和GPU图形渲染提出了一种森林群落的快速绘制技术。研究了植物茎枝和叶片随季节的生长变化模拟以及植物在风力等外界环境作用下的运动行为仿真模拟，提出了一种基于动态纹理变换和反向动力学的虚拟植物季相变化和运动摇曳模拟算法。研究成果在虚拟植物的拓扑结构可视化建模方面有广泛应用价值，也为基于植物生理生态特征的植物生长模拟奠定了基础。

中文关键词： 虚拟植物；形态结构建模；实时绘制技术；L~系统

英文摘要： In this project,we study the method of virtual plant morphological structure modeling and real-time rendering technology aimed to a great deal of virtual forest.We present and modify some algorithm to make these methods more efficient in plant visualization.We study the plant architechture character, especial the stem,leaves and flower.A general structure modeling framework of plant is provided based-on the L-system plant described rules.For simulating the high realistic plant leaf, we present a method of plant leaf modeling and rendering based on the modified DLA model and botanical theory.The leaf venation can generate automatically and highlighted the importance of leaf skeleton for triangulation and leaf deformation.We also forward a common visualization simulation algorithm for herbaceous flower morphology and growth based on real images and flower ecology. By combining the flower organ texture from segmentation with the bicubic Bezier curved surface, it is feasible to establish flower models with the predefined structure of leaves and petals.In order to improve the redering rate of great deal of trees, we present an algorithm based-on the LOD model simplification and GPU.At last,we present a method of virtual plant seasonal variation and virtual flower dynamic simulation based on dynamic texture mapping and inverse kinematics. The movement of flower can be regarded as a bending rod in mechanical space.To make the result more realistic, we take the elastic force in the skeletal plant nodes into consideration and realize smooth motion effect.These research results have a good future for the virtual plant simulation and are also the foundation of plant functional-structural model and plant development simulation based on the plant physiology and ecology.

英文关键词： virtual plant;architectural modeling;real-time rendering;L-system