多因素综合优化的矢量数据三维几何绘制的研究

发布时间：2018-03-24 11:24

本文选题：三维虚拟地球　切入点：三维矢量绘制　出处：《武汉大学》2014年博士论文

【摘要】：随着“数字地球”和“全球信息网格”的提出和实施,人们对真三维的空间信息的取得、应用及其推广已经从基本的局部和地段发展到城市级、国家级和全球范围,科学研究、军事研究、生产应用等都需要建立在海量的空间数据的基础之上,GIS的发展正经历着从二维GIS到三维GIS的深刻转变,正广泛且深刻的影响和改变着人们的生活。三维GIS的发展,能够包含和表达更加丰富的空间数据,突破二维数据对客观真实世界的表达的束缚,能重现人们真实世界的视觉感受,已作为未来GIS发展的方向备受企业界、学术界的关注。在三维GIS系统中,在栅格数据应用方面,GoogleEarth等3维GIS软件推出了实用化的栅格绘制技术,获得了巨大的成功,但在三维虚拟地球矢量应用方面由于存在瓶颈问题没有得到解决,离大规模的实用还有较大的差距。例如,目前3维软件只显示了主要城市的一些大比例尺的矢量数据,数据精度较差,不能直观的进行查询和分析,和DEM数据的结合也需加强,此外,大规模矢量数据的组织、绘制、查询、分析、统计等需要深入研究和技术攻关,才能早日走向实用化,其中,提供一个高效的矢量数据三维数据组织和绘制的解决方案是三维矢量数据查询、分析、统计和辅助决策支持的基础,是三维GIS系统中一个十分重要和具有挑战性的前沿研究问题。论文针对三维矢量数据的组织和绘制的迫切需求,针对研究存在屏幕绘制精度优化和插值数据量优化所有割裂现象、结合不够的现象,选取基于几何叠加法的三维矢量数据的组织和绘制作为研究内容,重点研究了考虑语义信息和基于优化算法数据源快速无级综合化简、结合考虑屏幕绘制精度优化、地形格网优化矢量插值数据量优化、矢量数据插值方法和矢量绘制数据集的一体化金字塔组织等关键技术问题,取得了下列具有创新性的研究成果：(1)分析三维矢量绘制的主要因素,提出了由三维矢量绘制的数据源、矢量数据的预处理、矢量数据的组织与储存、三维绘制策略和三维矢量绘制结果的评价方法这5个因素组成的5元组模型,同时,对该领域的研究问题进行了总结和分类。 (2)研究了相对平坦地区的三维线状矢量交点插值优化算法。首先,通过定义屏幕绘制N像素偏差或像素失真值,给出了屏幕绘制精度的形式化度量方法。针对三维矢量绘制中的插值研究存在屏幕绘制精度优化和插值数据量优化有所割裂、结合不够的现象,提出了结合考虑屏幕绘制精度的N像素失真地形优化格网模型,给出了构建算法。在此基础上,提出了基于地形优化格网模型的三维线状矢量交点插值优化顶点集的概念,给出了优化顶点集的求解算法,该方法采用优化后的多边形网格来对矢量数据进行插值,提出了对应N像素失真的优化地形网格和插值顶点的修正,实现了极端情况下的优化网格的实时修正。实验表明,该方法能够很好的降低矢量数据插值的数据量,显著提高矢量数据的绘制效率。 (3)提出一种基于遗传算法求取河网主流最优解的策略和方法,首先将河网结构的问题看作选取主流的问题,将选取主流的问题看作一个全局最优的问题,在全局优化的问题中综合考虑拓扑信息和语义信息。提出了使用遗传算法的求解策略。求取河流的主流,再建立河流的层次结构,实验验证了该方案的有效性。遗传算法能够综合考虑拓扑信息和水文、地形等语义信息,能够更为准确的找到河网的主流,是一种易于扩展、性能稳定的优化求解河网主流最优解方案。 (4)研究和实现了屏幕显示条件下河网数据的快速无级综合。在确定了河流的主流之后,使用常用的Horton编码,对水系数据进行分级和结构化,之后通过三维环境下的无级综合的动态分解尺度选取综合化简的要素,运用论文提出的综合算子,实现了屏幕显示条件下河网数据的快速无级综合。 (5)提出了一种三维矢量数据组织方法,使用等间隔经纬度格网的方式对球面进行剖分,建立一种不完全的区域四叉树,将原始的矢量数据与地形数据、优化后的矢量数据与地形数据、简化后的矢量数据和数据块的元数据这几个部分构建成新的数据块,并将这种新的数据块作为金字塔的基本元素建立矢量金字塔,最后,使用了大文件+索引的方式实现了服务端对矢量数据块的快速查询。 (6)提出了动态综合调用的优化绘制方法,在矢量数据进行绘制时,充分利用制图综合后的多比例尺数据和多等级各优化地形网格,在尽量减少绘制失真的情况下,尽可能地提高了绘制效率。 (7)研发了三维矢量绘制的原型系统,实现了论文提出的理论和方法,选用典型数据进行了相关实验,验证了提出的论文提出的理论和方法的正确性.
[Abstract]:With putting forward and implementation of "Digital Earth" and "global information grid", people get the spatial information of true 3D, applications and promotion have been developed from the basic level to the city and lots of local, national and global, scientific research, military research and production should be used should be established on the basis of space the huge amount of data, the development of GIS is experiencing profound change from 2D GIS to 3D GIS, widespread and profound influence and change people's life. The development of 3D GIS, and the expression of spatial data can contain more abundant, breaking the shackles of two-dimensional data on the expression of the objective of the real world, people can reproduce the vision of the real world experience, has as the future development direction of the GIS by business community, the attention of academic circles.
In the 3D GIS system, in the raster data applications, GoogleEarth 3 dimensional GIS software introduced a practical grid mapping technique, has achieved great success, but in the virtual 3D Earth vector application due to bottleneck problems have not been resolved, from the large-scale. There is a large gap. For example, the 3 dimension the software only shows some large scale vector data of the main city, poor accuracy of data, query and analysis is not intuitive, and combined with the DEM data also need to be strengthened, in addition, large vector data organization, drawing, query, analysis, statistics, need further research and technology research, in order to become practical, which provide an efficient vector data 3D data organization and rendering solutions of 3D vector data query, analysis, basic statistics and decision support, is a three-dimensional GIS system A very important and challenging frontier research issue.
Aiming at the urgent needs of the organization and rendering of 3D vector data, based on existing screen rendering all fragmentation precision optimization and interpolation data, combined with the insufficient, the selection of 3D vector data organization based on geometric superposition method and drawing as the research content, focus on the consideration of semantic information and fast optimization algorithm based on variable data comprehensive simplification, considering the screen drawing precision optimization, optimization of vector interpolation terrain grid data, the key technical problems of vector data interpolation method and vector drawing data set organization integration in Pyramid, research results obtained the following innovative: (1) the main factors analysis of 3D vector drawing, proposed by drawing the 3D vector data source, pretreatment of vector data organization and storage of vector data, 3D rendering and 3D vector strategy The evaluation method of the results is the 5 tuple model of the 5 factors. At the same time, the research problems in this field are summarized and classified.
(2) to study the optimization algorithm for 3D linear interpolation of vector intersection flat area. Firstly, through the definition of drawing on the screen N pixels or pixel value distortion deviation, formal measurement method of screen drawing precision is given. According to the interpolation of 3D vector drawing in the screen drawing precision optimization and data interpolation optimization has split, combination the insufficient, proposed considering N pixel screen rendering precision terrain distortion optimization grid model, gives the construction algorithm. On this basis, put forward the concept of optimal interpolation vector intersection vertex set like three-dimensional terrain line optimization based on grid model, gives the optimization algorithm for solving vertex set, the method uses polygonal mesh optimization after the interpolation of vector data, put forward the corresponding optimization N pixel distortion correction and interpolation of terrain mesh vertices, the extreme case The experiment shows that this method can reduce the amount of data interpolated by vector data well and improve the rendering efficiency of vector data remarkably.
(3) put forward strategies and a method based on genetic algorithm to find the optimal solution of the main river, the river network structure selection problem as the mainstream, the mainstream will be selected as a global optimization problem in global optimization problem in the topology information and semantic information. Considering the problem solving strategy the use of genetic algorithm. For the River mainstream, then establish hierarchical structure of the river, the experiment proves the validity of the proposed scheme. Genetic algorithm can consider the topology information and hydrology, topography and other semantic information, can more accurately find the River mainstream, is an easy extension, stable performance optimization solution the mainstream of river network optimal solution.
(4) the research and Realization of screen display stepless speed under the condition of network. After determining the River mainstream, using the Horton encoding used, classification and structure of data stream, followed by elements in 3D environment continuously integrated dynamic decomposition scale selection comprehensive simplification, using comprehensive operator the screen display realizes stepless speed under the condition of network.
(5) put forward a kind of 3D vector data organization method, using interval longitude latitude grid method to partition the sphere, establish an incomplete area of four binary tree, the original vector data and terrain data, vector data and terrain data after optimization, metadata and data blocks to simplify the vector data after the construction of new blocks into several parts, and the new data block as the basic elements of the establishment of the Pyramid Pyramid vector, finally, the use of a large file + index way to achieve fast query server of vector data block.
(6) put forward the method of dynamic synthesis call optimization. When drawing vector data, we should make full use of the multi-scale data and multi-level topographic grid after drawing, so as to minimize rendering distortion and improve the rendering efficiency as much as possible.
(7) the prototype system of 3D vector rendering is developed, and the theory and method put forward by the paper are implemented. Relevant experiments are done with typical data, which verifies the correctness of the theory and method put forward by the proposed paper.

【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P208

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