嵌入式三维地形可视化的设计与研究
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摘要
近年来,随着地理信息科学和计算机图形学的不断融合产生了三维地形可视化这一新兴的领域。三维地形可视化应用三维图像技术对利用现代化的地理测量手段所采集的各种地理数据进行地形可视化建模,并通过纹理映射来逼真地模拟现实世界中的地理环境,该技术对国防、交通、农林业、娱乐产业来说具有重要的应用价值。本文所讨论的是嵌入式平台下的三维地形可视化,目前国内基于嵌入式的三维地形可视化研究才刚刚起步,与国外已有产品相比还有很大的不足,因此有必要对嵌入式平台下的三维地形可视化进行研究和设计。
论文介绍了三维地形生成方法。首先是规则三角形网格模型的生成方法。然后,对狄洛尼三角划分理论进行阐述,分析狄洛尼三角划分算法;在此基础上把理论和算法相结合进行地形模型的生成,对插入算法进行优化,并实现了带约束的狄洛尼三角网算法。
实现了对三维场景中地理数据的处理和组织。对DEM数据和纹理数据按照一定的要求进行分块,并对各个地形子块和纹理子块进行多分辨率的处理,使得它们具有不同的层次细节。建立了索引机制,将经过处理的DEM数据和纹理数据存入嵌入式数据库,并利用场景四叉树结构对三维场景中的数据进行组织,以方便实施场景数据的调度策略,提高场景显示的效率。
设计了嵌入式三维场景显示过程中的数据调度方案。通过适当简化场景可见性的判断方法以提高场景调度的速度;利用多线程技术对场景调度与场景显示进行了同步,并分析视点的运动方式以预测下一帧场景数据调度的范围,通过将这些数据预先加载到内存以保证场景能够流畅的显示。
In recent years,with the integration of Geographic Information Science and Computer Graphics, a new field called Three-Dimentional Terrain Visualization is emerging. It uses various geographic data which collected by modern measurement methods and three-dimentinal image technology to visulize the terrain, then vividly simulates real-world geography environment by texture mapping. This techology is of great importance upon national defence, transportion, agriculture, forestry and entertainment.
This thesis mianly discusses three-dimentional terrain under embedded operating systems. The research upon embedded three-dimentional terrain visualization has just started in our country. It’s insufficient compared with foreign products. Accordingly, it’s necesssry to research and design three- dimentional terrain visualization.
This thesis introduces the generating methods of three-dimentional terrain. First discuss the generating method of regular triangular mesh model. Next, illustrates Delauay’s triangulation theory, analyses Delaunay triangulation algorithm. Then combines the theory and the algorithm to generate the terrain model, optimizes the insert algorithm, and finally realizes the constrainted Delaunay triangulation algorithm and the data processing and organization in three-dimentional cicumstance. It can divide the DEM data and texture data according to some requirement, manage each terrain sub-block and texture sub-block to make them have different levels of detail.Builds an index system, and stores the DEM data, texture data into the embedded database, organizes the data of three-dimentional scene data with scene quadtree strucure to facilitate the implementation of scheduling of scene data, improve the effiency of the scene display.
This thesis designs data scheduling solution of the embedded three-dimentional scene during its display process. Improves the speed of scene scheduling by simplifying scene visibility’s judgement. Synchronizes the scene scheduling with multithreading technology. Analyzes the motion mode of viewpoint. In order to predict the scheme of the next data operation. Preload these datas to memory to ensure the smoth show of the scene.
论文介绍了三维地形生成方法。首先是规则三角形网格模型的生成方法。然后,对狄洛尼三角划分理论进行阐述,分析狄洛尼三角划分算法;在此基础上把理论和算法相结合进行地形模型的生成,对插入算法进行优化,并实现了带约束的狄洛尼三角网算法。
实现了对三维场景中地理数据的处理和组织。对DEM数据和纹理数据按照一定的要求进行分块,并对各个地形子块和纹理子块进行多分辨率的处理,使得它们具有不同的层次细节。建立了索引机制,将经过处理的DEM数据和纹理数据存入嵌入式数据库,并利用场景四叉树结构对三维场景中的数据进行组织,以方便实施场景数据的调度策略,提高场景显示的效率。
设计了嵌入式三维场景显示过程中的数据调度方案。通过适当简化场景可见性的判断方法以提高场景调度的速度;利用多线程技术对场景调度与场景显示进行了同步,并分析视点的运动方式以预测下一帧场景数据调度的范围,通过将这些数据预先加载到内存以保证场景能够流畅的显示。
In recent years,with the integration of Geographic Information Science and Computer Graphics, a new field called Three-Dimentional Terrain Visualization is emerging. It uses various geographic data which collected by modern measurement methods and three-dimentinal image technology to visulize the terrain, then vividly simulates real-world geography environment by texture mapping. This techology is of great importance upon national defence, transportion, agriculture, forestry and entertainment.
This thesis mianly discusses three-dimentional terrain under embedded operating systems. The research upon embedded three-dimentional terrain visualization has just started in our country. It’s insufficient compared with foreign products. Accordingly, it’s necesssry to research and design three- dimentional terrain visualization.
This thesis introduces the generating methods of three-dimentional terrain. First discuss the generating method of regular triangular mesh model. Next, illustrates Delauay’s triangulation theory, analyses Delaunay triangulation algorithm. Then combines the theory and the algorithm to generate the terrain model, optimizes the insert algorithm, and finally realizes the constrainted Delaunay triangulation algorithm and the data processing and organization in three-dimentional cicumstance. It can divide the DEM data and texture data according to some requirement, manage each terrain sub-block and texture sub-block to make them have different levels of detail.Builds an index system, and stores the DEM data, texture data into the embedded database, organizes the data of three-dimentional scene data with scene quadtree strucure to facilitate the implementation of scheduling of scene data, improve the effiency of the scene display.
This thesis designs data scheduling solution of the embedded three-dimentional scene during its display process. Improves the speed of scene scheduling by simplifying scene visibility’s judgement. Synchronizes the scene scheduling with multithreading technology. Analyzes the motion mode of viewpoint. In order to predict the scheme of the next data operation. Preload these datas to memory to ensure the smoth show of the scene.
引文
[1]孙以义.计算机地图制图[M].北京:科学出版社, 2000.
[2]邬伦等.地理信息系统:原理、方法和应用.北京:科学出版社, 2001.
[3] Kang Tsung Chang.Geographic Information Systems.北京:科学出版社, 2006.
[4] David H. Eberly.3D Game Engine Design, A Practical Approach to Real-Time Computer Graphics[M].BeiJing:Posts & Telecom Press, 2009.
[5]史文中等。三维空间信息系统模型与算法[M].北京:电子工业出版社, 2007.
[6] MarkSega, MarkSega . The OpenGL Graphics System : A Specification (Version1.5)[M].Silicon Graphics.2003.
[7]胡少林.基于DEM数据的三维地形建模方法研究与实现[D].北京:国防科技大学, 2002.
[8]龚健雅.地理信息系统基础[M].北京:科学出版社, 2001, 4.
[9]杨钦等.任意平面域上离散点集的三角化方法(J).软件学报, 1998, 9(4):241-244.
[10] R.E.Miles. On the homogeneous Planar Poisson Process[M]. Mathematical Bioscience, 1970, Vol.6, 85-127.
[11]武晓波等. Delaunay三角网的生成算法研究[J].测绘学报, 1999, 28(1), 28-35.
[12] Lawson, C.L. A software for C surface interpolation[M].New York:Academic Press, 1977:161-94.
[13]吴慧欣.三维GIS空间数据模型及可视化技术研究[D].西安:西北工业大学, 2007.
[14] O.DevillerS, M.Teillaud.Walking in a triangulation[J].ACM SylnPonComPutGeometry, 2001, 106-144.
[15]朱庆,陈楚江.不规则三角网的快速建立及其动态更新[J].武汉测绘科技大学学报, 1998, 23(3):204-207.
[16]蒲浩,宋占峰,詹振炎.快速构建三角网数字地形模型方法的研究[J].中国铁道科学, 2001, 22(6):100-106.
[17] CHEWLP.Constrained Delaunay Triangulation, in Proceedings of Third[M].Proceedings of Third ACM Symposium on Computational Geometry, 1987.
[18] Anglada, M V.An Improved Incremental Algorithm for Constructing Restricted Delaunay Triangulation[J].Computer&Graphics, 1997.
[19] http://msdn.microsoft.com/en-us/library/ms172037(SQL.90).aspx.
[20]余金山,林慧编著.SQL Server 2000/2005数据库开发实例入门与提高[M].北京:电子工业出版社.2006.
[21]张欢钮文良. Windows CE系统开发基础与实例[M].北京:中国电力出版社.2009.
[22]袁玲,臧建华.OLE DB/ADO数据访问对象和接口[J].电脑学习,2001,(02):28-30.
[23] Gamma等著,吕建等译.设计模式:可复用面向对象软件的基础[M].北京:机械工业出版社, 2000.
[24]傅曦等著.Windows Mobile手机应用开发[M].北京:人民邮电出版社,2005.
[25]王宏武,董士海.一个与视点相关的动态多分辨率地形模型.计算机辅助设计与图形学学报, 2000, 12(8):575-579.
[26] Dave Shreiner, Mason Woo.OpenGL Programming Guide: The Official Guide to Learning OpenGL[M] . Addison-Wesley Professional, 2008.
[27] Christophe Bobineau, Luc Bouganim, Philippe Pucheral, Patrick Valduriez.“PicoDBMS:Scaling down Database Techniques for the Smartcard”.Proceeding of the 26th International Conference on Very Large Databases, Cairo, Egypt.2000.
[28] Stefan Zerbst,Oliver Duvel. 3D Game Engine Programming[M].BostonThomson Course Technology, 2004.
[29]温菊屏.分布式三维实时漫游系统数据存储和调度方法研究[J].计算机与数字工程, 2004.
[30]唐泽圣.三维数据场可视化[M].北京:清华大学出版社, 1999.
[31]张应俊,贾利民.数字高程模型及在铁路交通中的应用[J].铁路计算机应用, 2007.
[32] Daniel W. Lewis. Fundamentals of embedded software: where C and assembly meet[M]. Pearson Education, 2005.
[33]李佳.ARM系列处理器应用技术完全手册[M].北京:人民邮电出版社,2006.
[2]邬伦等.地理信息系统:原理、方法和应用.北京:科学出版社, 2001.
[3] Kang Tsung Chang.Geographic Information Systems.北京:科学出版社, 2006.
[4] David H. Eberly.3D Game Engine Design, A Practical Approach to Real-Time Computer Graphics[M].BeiJing:Posts & Telecom Press, 2009.
[5]史文中等。三维空间信息系统模型与算法[M].北京:电子工业出版社, 2007.
[6] MarkSega, MarkSega . The OpenGL Graphics System : A Specification (Version1.5)[M].Silicon Graphics.2003.
[7]胡少林.基于DEM数据的三维地形建模方法研究与实现[D].北京:国防科技大学, 2002.
[8]龚健雅.地理信息系统基础[M].北京:科学出版社, 2001, 4.
[9]杨钦等.任意平面域上离散点集的三角化方法(J).软件学报, 1998, 9(4):241-244.
[10] R.E.Miles. On the homogeneous Planar Poisson Process[M]. Mathematical Bioscience, 1970, Vol.6, 85-127.
[11]武晓波等. Delaunay三角网的生成算法研究[J].测绘学报, 1999, 28(1), 28-35.
[12] Lawson, C.L. A software for C surface interpolation[M].New York:Academic Press, 1977:161-94.
[13]吴慧欣.三维GIS空间数据模型及可视化技术研究[D].西安:西北工业大学, 2007.
[14] O.DevillerS, M.Teillaud.Walking in a triangulation[J].ACM SylnPonComPutGeometry, 2001, 106-144.
[15]朱庆,陈楚江.不规则三角网的快速建立及其动态更新[J].武汉测绘科技大学学报, 1998, 23(3):204-207.
[16]蒲浩,宋占峰,詹振炎.快速构建三角网数字地形模型方法的研究[J].中国铁道科学, 2001, 22(6):100-106.
[17] CHEWLP.Constrained Delaunay Triangulation, in Proceedings of Third[M].Proceedings of Third ACM Symposium on Computational Geometry, 1987.
[18] Anglada, M V.An Improved Incremental Algorithm for Constructing Restricted Delaunay Triangulation[J].Computer&Graphics, 1997.
[19] http://msdn.microsoft.com/en-us/library/ms172037(SQL.90).aspx.
[20]余金山,林慧编著.SQL Server 2000/2005数据库开发实例入门与提高[M].北京:电子工业出版社.2006.
[21]张欢钮文良. Windows CE系统开发基础与实例[M].北京:中国电力出版社.2009.
[22]袁玲,臧建华.OLE DB/ADO数据访问对象和接口[J].电脑学习,2001,(02):28-30.
[23] Gamma等著,吕建等译.设计模式:可复用面向对象软件的基础[M].北京:机械工业出版社, 2000.
[24]傅曦等著.Windows Mobile手机应用开发[M].北京:人民邮电出版社,2005.
[25]王宏武,董士海.一个与视点相关的动态多分辨率地形模型.计算机辅助设计与图形学学报, 2000, 12(8):575-579.
[26] Dave Shreiner, Mason Woo.OpenGL Programming Guide: The Official Guide to Learning OpenGL[M] . Addison-Wesley Professional, 2008.
[27] Christophe Bobineau, Luc Bouganim, Philippe Pucheral, Patrick Valduriez.“PicoDBMS:Scaling down Database Techniques for the Smartcard”.Proceeding of the 26th International Conference on Very Large Databases, Cairo, Egypt.2000.
[28] Stefan Zerbst,Oliver Duvel. 3D Game Engine Programming[M].BostonThomson Course Technology, 2004.
[29]温菊屏.分布式三维实时漫游系统数据存储和调度方法研究[J].计算机与数字工程, 2004.
[30]唐泽圣.三维数据场可视化[M].北京:清华大学出版社, 1999.
[31]张应俊,贾利民.数字高程模型及在铁路交通中的应用[J].铁路计算机应用, 2007.
[32] Daniel W. Lewis. Fundamentals of embedded software: where C and assembly meet[M]. Pearson Education, 2005.
[33]李佳.ARM系列处理器应用技术完全手册[M].北京:人民邮电出版社,2006.