【作者】 李玉娟；

【导师】 谭同德；

【作者基本信息】 郑州大学 ， 计算机应用技术， 2013， 硕士

【摘要】 三维虚拟地理场景仿真系统是一种能够模拟现实地理环境的系统,用户可以在工程建好之前,通过系统对场景进行欣赏,模拟的场景往往比图纸展示的效果更为直观。在场景中已经基本上能够完成渲染,然而,随着场景的不断扩大,数据分解的面片数量不断增多,造成图形处理滞后,这样系统就不能保证实时和稳定的交互。在大规模场景下必然要求有合适的算法,因此研究大规模地形生成和线路的交互绘制有着积极的意义。本文将地形与道路资料相结合,实现了一个用户可以与计算机相交互的系统。根据课题的需求,本文着重研究了地形真实感场景的生成、线路的交互绘制问题。主要研究工作如下：首先,对现有的经典地形和线路交互算法进行了总结,分析了多种算法的适用范围以及不足,为本文的研究和实现奠定了基础。其次,结合数据库设计了地形分块处理流程,提出通过对比各项性能选择了合适的地形分块。针对边插入和边删除裂缝修补算法的不足,提出了采用实际高程代替插值高程的修补裂缝方法。再次,以三维地形为载体,采用鼠标交互点选的方式,设计线路的走向,实现三维线路建模。最后,通过搭建实验环境仿真,实现了一个三维虚拟地理场景的仿真系统,满足了大规模场景的实时性,验证了方法的有效性,同时分析了系统设计过程中存在的不足之处和以后需要改进的地方。更多还原

【Abstract】 The3D virtual geography scene simulation system is a system to be able to simulate the real geographic environment. Virtual environment effect is more intuitive than the drawings, so that users can enjoy the scene before the project completed. The system has basically been able to complete the rendering in the scene; however, with the continuous expansion of the scene, the number of the data decomposition facets increases, resulting in graphics processing lag, so the system can not be guaranteed the real-time and stable interaction. In the large-scale system, the appropriate algorithm is required; therefore, there is a great significance for the study of large terrain generation and line interactive drawing. This paper achieves a system that users can easily with the computer, combined the terrain with road design data.According to the requirements of the subject, this paper focuses its research on interactive Terrain generation and line drawing, and so on. This paper has done the following work:First, the paper summarizes the existing classic terrain and roads algorithms, analyzes the scope and limitations in3D virtual geography scene of different algorithms. This lays the foundation for the research and implementation of the paper.Second, this paper designs the terrain chunking process combined with database, and selects suitable terrain block by comparing the performance. Aiming at the deficiencies of edge insertion and edge deletion crack repairing algorithms, this paper puts forward a method of crack repair of actual elevation instead of interpolated elevation.Again, with the3D terrain as a carrier, this paper uses the method of interactive mouse click, designs the trend line, and achieves the three-dimension line modeling.Finally, by setting up an experimental environment simulation, this paper implements a simulation system of the three-dimensional virtual geography scene, satisfies the real-time of the large-scale scenes, and verifies the feasibility of the program, while analyzes the inadequacies and subsequent improvement that exist in the system.更多还原