地质体三维模型和数据结构的研究与实现

【作者】 段福洲；

【导师】 宫辉力； 赵文吉；

【作者基本信息】 首都师范大学 ， 自然地理学， 2004， 硕士

【摘要】 在地理信息系统(GIS)及其应用的研究中，空间实体的三维表达与分析、可视化是十分重要的研究内容。如针对矿山特性和应用，构造三维数据结构，实现三维实体(矿体、巷道、断层、井筒等)表达、现象模拟、空间分析和可视化是矿山3DGIS深入应用的要求。利用3DGIS和三维可视化技术来反映地下水水文地质层的结构、地下水的赋存环境、地下水水位、水质等的时空分布及地下水流场的运动变化规律，地下水降落漏斗的形成与发展过程以及地下水污染物的运移规律等，借助三维可视化分析的手段来辅助决策地下水资源的科学管理是3DGIS在地下水领域深入应用的要求。在这些研究中，地下三维地质体的表达研究是基础，其重点是地质体三维模型、三维数据结构以及三维可视化技术的研究。 地质调查和观察的结果往往是一系列离散的、空间上分布不均匀的数据，对许多现象的解释，大多是基于这些数据做出的。运用三维模拟与可视化方法，准确地表示和描述复杂的地质现象，如断层、褶皱及复杂的岩石特征变化，建立简单有效、准确的地质体三维数学模型以及高效率支持该模型的数据结构是三维地质体研究的重点。笔者所进行的研究工作正是为解决这一问题而展开的，其基本思路是采用多层DEM和四面体的混合模型建立地质体的三维模型，表现地质体的时空分布规律。作者主要完成了以下系列研究工作： 1．在论文的第一章：阐述了地理信息系统的各个发展阶段，从目前矿山、油层、地下水等方面研究的角度阐明了论文的选题背景及研究意义。在此基础上确定了论文的主要研究目标、主要研究内容及论文的组织结构。 2．在论文的第二章：对比分析了地质体的各种形态以及适用不同形态的不同模型；并对地质体三维模型和数据结构研究、地质体三维可视化技术研究的国内、外现状作了系统回顾和总结。 3．在论文的第三章：地下三维地质体可视化系统的设计研究。 4．在论文的第四章：作者系统的研究了地质体的各种三维数学模型和三维数据结构，重点阐述了作者所采用的多层DEM和四面体混合模型及其数据结构，并且给出了生成这种模型的三维数据的具体算法。 5．在论文的第五章：总结了满足地学插值特点的插值方法应具备的三个基本条 件，分析对比了多种插值算法的优缺点，阐述了曲面磨光算法、Kring插值算 法以及改进的距离加权插值算法的算法过程，并运用这些方法形成了地层数 据。6.在论文的第六章:对比研究了规则格网和不规则三角网的特点，提出了规则 格网的细节层次模型以及基于二叉树的视相关动态简化方法，同时根据不规 则三角网的特点提出基于点删除的视相关三角网动态简化方法，并给出了相 应的算法和流程图。7.在论文的第七章:介绍了地质体三维交互编辑的实现技术，阐述了三维旋转、 平移的算法公式，提出了基于地质体表面的鼠标三维坐标计算方法，并给出 了地质体垂直切面、水平切面、等厚度图生成、地层体积计算等方面的算法 过程和计算结果示例。8.在论文的第八章:对论文研究成果的进行了总结，并对未来三维地质体研究 进行了展望。更多还原

【Abstract】 It is important in the research of the application and 3D GIS.to describe , analyse and visualize the 3D spatial entities ,it is necessary to construct 3D data structure and realize 3d entities(such as mine body, laneway, faultage, well etc..) drescribing,phenomena simulation , spatial analyse and 3D visualization in the deep application of 3DGIS on mine. The researches how to express the structure of hydrogeologic stratum, the existent condition of groundwater, the level of groundwater and the quality of groundwater and how to disclose moving regulation and dynamic characteristic of groundwater stream, form and development of groundwater cone of depression and land subsidence are in favor of the reasonable management of the groundwater resource. All these researches base on 3d geologic volume describing and the emphases are 3D model of geologic volume, 3D data structure and 3D visualization of geologic volume.The datum of geologic survey and observation is sometimes discrete and asymmetry, by which many phenomena are interpreted. The complicated geologic phenomena such as faultage, drape etc. are accurately represented and described through 3D simulation and visualization. The simple and available 3D mathematics model of geologic volume and the efficient 3D data structure are built. These are emphases in the research on 3D geologic volume. To solve this problem ,the author does a lot of research work. The basic thinking is to built 3D model, which are mingled by multiplayer DEM and tetrahedron , to disclose the rule of geologic volume distributing in the space and time. During the course of research, the author finishes the work as follows primarily.1.In the Chapter One, the paper tells four development phase of GIS , the condition and the purport on the research theme which are evaluated through the research on mine , crude petroleum layer and ground water ,then decides the primary research subject and the research context and the organization of the paper.2.In the Chapter Two, the paper reviews and sums up the present situation of3D model, data structure and 3D visualization of geologic volume at home and aboard systematically. It contrasts and analyses each form of geologic volume and many types of 3D model and data structure of the geologic volume.3.In the Chapter Three, the author develops the software system "the 3D visualization of geologic volume" by using VC++6.0 and the visualization toolkit named OpenGL.4.In the Chapter Four, the paper reviews and sums up systematically all sorts of 3D modle and data structure of geologic volume. It emphasizes on expounding the 3D model mingling multilayers DEM and tetrahedron model and its data structure, then it represents the algorithm to generate 3D model datum.5.In the Chapter Five, the paper brings forward three basic provisions of the method of interpolation in the Geo-field. It analyses and evaluated a lot of the methods of interpolation. The paper expounds the method of blending surface, the Kring method and the improved inverse distance to a power method. Then the 3D datum are generated by these methods.6.In the Chapter Six, the paper evaluates regular grids and TIN, which also brings forward Lod of regular grids and the algorithm of regular grids base on quadric tree whose features include view-dependent, real-time and multi-level. Then with regard to the generating rules and data structure of TIN , it expounds the algorithm to dynamically Simple the Triangulated Irregular Network based on viewpoint and viewaxis and the flow graphy.7.In the Chapter Seven, the paper represents 3D interacting model to edit geologic volume datum, the algorithm and formula of rotate and translate. It expounds how to convert 2D coordinates of mouse to 3D coordinates through assistant surface. Then, it represents the methods how to calculate upright slices, level slices, isoline of depth and bulk of geo_layer.8.In the Chapter Eight, Sum up the research work in the paper completely and point out the further research direction and problems.更多还原