共查询到20条相似文献，搜索用时 154 毫秒
1.
JINBaoxuan BIANFuling ZUOXiaoqing WANGFangxiong 《地球空间信息科学学报》2005,8(2):115-121
With the rapid development of computer graphics, distributed-computing and Internet, it is possible to achieve Internet-based virtual city. This paper dwells on the method of the terrain and its feature modeling and complex entity modeling in the virtual city. Then, discusses the method for Internet-based virtual city 3D visualization and the design of the Browser/Server architecture of the system of virtual city in the network environment. Finally, Java and Java 3D are used to show an experiment example, and the related conclusion about Internet-based virtual city 3D displaying and the client-side interactive operation is given. 相似文献
2.
The problem of taking an unorganized point cloud in 3D space and fitting a polyhedral surface to those points is both important and difficult. Aiming at increasing applications of full three dimensional digital terrain surface modeling, a new algorithm for the automatic generation of three dimensional triangulated irregular network from a point cloud is proposed. Based on the local topological consistency test, a combined algorithm of constrained 3D Delaunay triangulation and region-growing is extended to ensure topologically correct reconstruction. This paper also introduced an efficient neighboring triangle location method by making full use of the surface normal information. Experimental results prove that this algorithm can efficiently obtain the most reasonable reconstructed mesh surface with arbitrary topology, wherein the automatically reconstructed surface has only small topological difference from the true surface. This algorithm has potential applications to virtual environments, computer vision, and so on. 相似文献
3.
WULixin SHIWenzhong 《地球空间信息科学学报》2004,7(2):123-128
Engineering excavation GIS (E^2GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model.As two instances of GTP model, G-GTP is used for the real-3D modeling of subsurface geological bodies, and E-GTP is used for the real-3D modeling of subsurface engineering excavations. In the light of the discussions on the features and functions of E2 GIS, the modeling principles of G-GTP and E-GTP are introduced. The two models couple together seamlessly to form an integral model for subsurface spatial objects including both geological bodies and excavations. An object-oriented integral real-3D data model and integral spatial topological relations are discussed. 相似文献
4.
Human beings use hierarchies to simplify their conceptual models of reality and to perform reasoning more efficiently. Hierarchical structures are conceptually imposed on space and allow performance of complex tasks in very large contexts easily. Hierarchical spatial reasoning is an important method for solving spatial problems. This paper briefly discusses the definition and frame of hierarchical spatial reasoning and its application to way-finding of road networks. 相似文献
5.
3D (three-dimensional) process simulation is currently one of the most challenging fields of research on debris flow.Large scale terrain rendering is the most basic task of 3D scenery construction in debris flow simulation.As the major trigger for debris flow,rainfall will substantially enhance the realistic sense.Terrain and rainfall rendering in 3D debris flow simulations poses great challenges for numerical computation and graphical processing capability.In this paper,we propose to integrate GPU technology,LoD algorithms,and particle systems to realize 3D scenery modeling and rendering.The real-time LoD-based terrain modeling and rendering algorithm is presented first,and then a particle system-based rainfall scenery rendering method is implemented.Experimental results demonstrate that the 3D scenery rendered with the proposed approach exhibits sound performance and fair visual effects,which lays a solid foundation for the whole process simulation of debris flow disasters. 相似文献
6.
WUJun CHENDanqing 《地球空间信息科学学报》2005,8(1):39-44
Texture extract from digital aerial image is widely used in three-dimensional city modeling to generate “photo-realistic” views. In this paper, a method based on reforming “Steep edge” curve, which clearly explains how the diffraction of the sunlight makes digital aerial image blurring, is proposed to deblur the texture extraction from digital aerial image, and the experiment shows a good result in visualization and automation. 相似文献
7.
FENGYucai YIBaolin 《地球空间信息科学学报》2004,7(4):297-302
Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries. 相似文献
8.
Transect-based three-dimensional road modeling and visualization 总被引：3，自引：0，他引：3
LIQingquan TANGLuliang ZUOXiaoqing LIHanwu 《地球空间信息科学学报》2004,7(1):14-17
On the basis of the study on road elements and the existing three-dimensional road data models, this paper puts forward the transect-based road modeling, resolves the modeling of the simplest road with two road transects, and fulfils the visualization of the road. OpenGL is applied as the tool of visualization. The map texture technology, LOD algorithm and dynamic multi-differentiating texture technology are of benefit to the construction of 3D road GIS, and improve the speed of roaming and effective visualization. This paper also disusses the combination of 2D digitall road map and 3D road scene, and the dynamic response between them. Finally, on the basis of the research on the transect-based road model, this paper develops the three-dimen-sional road geographic information system called virtual road ( VRoad ), which not only supplies road designers with a set of tool which can turn the designed 2D road data into 3D road and the high road assistant function area in computer, but also supplies the road management with a set of tool which can realize the road real time and interactive roaming, high-efficiency management. 相似文献
9.
YIN Hui 《地球空间信息科学学报》2000,3(3):69-72
The methods of deformation analysis and modeling at single point are realized easily now,but available approaches do not make full use of the information from monitoring points and can not reveal integrated deformation regularity of a deformable body.This paper presents a fuzzy clusetering method to analyze the correlative relations of multiple points in space,and then the spatial model for a practical dangerous rockmass in the area of Three Gorges,Yangtze River is established,in which the correlation of six points in space is analyzed by geological investigation and fuzzy set theory. 相似文献
10.
LI DerenWANG YandongZHU QingGONG Jianya LI Deren Academician Professor National Laboratory for Information Engineering in Surveying Mapping Remote Sensing WTUSM Luoyu 《地球空间信息科学学报》1999,2(1):21-25
Data acquisition and modeling are the two important, difficult and costful aspects in a Cybercity project. 2D-GIS is mature and can manage a lot of spatial data. Thus 3D-GIS should make the best of data and technology of 2D-GIS. Construction of a useful synthetic environment requires integration of multiple types of information like DEM, texture images and 3D representation of objects such as buildings. In this paper, the method for 3D city landscape data model and visualization based on integrated databases is presented. Since the data volume of raster are very huge, special strategies(for example, pyramid gridded method) must be adopted in order to manage raster data efficiently. Three different methods of data acquisition, the proper data structure and a simple modeling method are presented as well. At last, a pilot project of Shanghai Cybercity is illustrated. 相似文献
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12.
利用规则统一三维实体间的语义形式化表达,为建模提供统一的方法。利用三维矢量数据模型的框架,对直钻孔、斜孔、剖面、等值线、断层、褶皱等数据源,分别按规则制定一种数据格式,对多源地质数据进行标准化和信息融合,经过地质面和地质体的快速构建,提出了建立基于规则库的三维矢量数据模型。同时研究了适合各类地质特点的三维模型自动构建方法,包含多源数据耦合层状地质体自动建模技术、基于剖面单元格划分的分区—拼接自动建模技术、多约束下复杂地质结构快速建模技术、空间约束条件下三维地质属性建模技术等。在确保模型精度的前提下,尽量减少人工交互建模的工作量,提高了建模效率。 相似文献
13.
胡超伦 《测绘与空间地理信息》2017,(8)
三维激光扫描技术相对于传统的数据采集方式具有更高精度、远距离获取等优势。本文介绍了三维激光扫描技术的工作原理,并结合地质剖面分析了点云数据的采集以及获取的流程,结合生成的地质剖面模型讨论了点云数据在地质剖面分析方面的优势以及存在的问题。 相似文献
14.
在地质建模中,基于层面的地质块体结构模型的获取是其中最重要的环节之一,目前的构建方法仅关注地质块体的提取和算法效率的提高,忽略了对地质块体与其组成面片以及各地质块体之间拓扑关系的建立,为此,本文提出了一种新的构建方法,基本思路是：首先,利用边界线与曲面片的关系,提取方向边和方向三角形,其次,按照右手法则建立面片排序表,最后,按照一定的遍历规则获取每个面片的正体和负体。此方法不仅可以自动确定地质块体与地质曲面片的组成关系,还可间接分析地质块体之间的邻接关系,从而为三维地质体模型的建立以及三维地质体拓扑查询和分析奠定基础。 相似文献
15.
张好贤 《测绘与空间地理信息》2020,(2):163-165
利用MapGIS-TDE作为建模基础平台,探索研究了多层地质界面模型的表达方法,形成了顾及层序的自助建模流程,对研究区域前期较少的勘测数据进行分析后形成了区域三维地质模型,客观地反映出了勘查区的勘查现状。 相似文献
16.
矢量剪切技术在地质三维建模中的应用 总被引：1，自引：0，他引：1
三维地质建模方法是地学三维模拟与可视化系统的核心和难点。基于BSP树的矢量剪切的原理及算法,提出了利用矢量剪切技术快速构建复杂的地质体开挖模型,可视化表达地质体内部信息的方法,并以地质开挖工程及三维地层分析为例,验证了算法的高效性和实用性。 相似文献
17.
路线剖面图是区域地质调查平面图的重要补充,其三维重建可明确反映地质层面的地表展布与地下发育情况,是重建区域三维地质模型的必要数据。针对区域地质调查路线距离长、褶曲多、地质结构复杂的特点,本文建立了一种基于纵向定位线的剖面特征点三维坐标转换模型,提出了地质界线特征点加密算法,能够有效地提高重建路线三维剖面的准确度与光滑度。研发的剖面三维重建模块已应用于多幅实际区调数据工程项目,应用结果表明:该方法可满足区域地质调查建模需求,剖面重建效果良好,具有较好的实用价值和应用前景。 相似文献
18.
针对三维地质建模工作繁琐、复杂,从手工绘制地质模型角度提出了一种基于GIS耦合SketchUp技术的三维地层模型绘制方法。采用钻孔资料作为数据源,通过ArcGIS的插值和栅格转换工具生成地层三角网格。然后利用SketchUp的封面插件和表面求交工具,生成地层的三维体模型。该方法操作简单、直观和易于掌握,具有一定的推广和应用价值。 相似文献
19.
提出一种基于GIS的简单、快速和直观的3维地质建模及可视化方法。利用ArcGIS的VBA语言编写钻孔数据提取程序生成钻孔3维模型;通过空间插值工具生成地层的TIN表面模型,并基于矢量化工具获取的断裂线生成断层的3维表面模型,从而组合成地质构造的结构模型。此外,利用C#语言基于SceneControl组件开发了3维地质可视化系统原型,并对构建的地质结构模型进行了展示。系列实验结果表明,该方法具有操作简单、可视化效果好和系统开发周期短的特点,在地学研究、工程应用和其他相关领域具有一定的推广应用价值。 相似文献
20.
虚拟现实建模语言(VRML)以其强大的3维建模功能、人机交互能力、跨平台以及强大的集成能力,有望成为构建地质体3维模型的一种新方法。本文采用虚拟现实建模语言(VRML)作为建模语言,探讨了VRML环境下实现地质体3维可视化的一般方法,结果表明:在达到同样良好的视觉效果的前提下,相较于底层开发语言,VRML具有几何原型模块化、包围盒检测模块化的特点,可视化方法简便,同时,VRML还具有低带宽可行性,方便地质3维模型的即时可视化与浏览;相较于专门的地质3维建模及分析工具软件,VRML具有可视化方法灵活,可视化成果可移植性好,且不受平台约束等特点,适用于钻孔数据、剖面数据等数据源的可视化需求,为实现地质体3维模型可视化提供了一条新的解决途径。 相似文献