GIS的发展方向   总被引：9，自引：0，他引：9  

巩慧  赵文吉 《世界地质》1999,18(1):60-63

介绍了地理信息系统的理论基础,总结了ＧＩＳ在３Ｓ集成,面向对象技术,ＧＩＳ与专家系统相结合,ＧＩＳ的网络化,ＧＩＳ与多媒体技术及虚拟现实技术相结合等方面的发展。  相似文献   

基于虚拟现实技术的排水管道损伤粘合修复方法          下载免费PDF全文

于泰然  田爽  张晗 《探矿工程》2020,47(7):106-111

传统的地下排水管道损伤粘合修复方法修复后外渗较多,为了解决这一问题,基于虚拟现实技术提出了一种新的排水管道损伤粘合修复方法,通过负压波形图法定位排水管道的损伤位置和损伤程度,然后通过通信模拟器进行排水管道损伤信号的输送,计算机输出排水管道的损伤鉴定,采用虚拟仿真技术,应对不同损伤程度的排水管道,合理地进行粘合修复处理。结果表明,与传统修复方法相比,基于虚拟现实技术的排水管道损伤粘合修复材料更加合理,在修复后会通过特殊试剂进行清洗,提高了排水管道损伤处的粘合效果,降低排水管道损伤粘合修复后的外渗量。  相似文献   

An improved segmentation approach for planar surfaces from unstructured 3D point clouds     

Tarek M.  Awwad  Qing  Zhu  Zhiqiang  Du  Yeting  Zhang 《The Photogrammetric Record》2010,25(129):5-23

The extraction of object features from massive unstructured point clouds with different local densities, especially in the presence of random noisy points, is not a trivial task even if that feature is a planar surface. Segmentation is the most important step in the feature extraction process. In practice, most segmentation approaches use geometrical information to segment the 3D point cloud. The features generally include the position of each point (X, Y and Z), locally estimated surface normals and residuals of best fitting surfaces; however, these features could be affected by noisy points and in consequence directly affect the segmentation results. Therefore, massive unstructured and noisy point clouds also lead to bad segmentation (over-segmentation, under-segmentation or no segmentation). While the RANSAC (random sample consensus) algorithm is effective in the presence of noise and outliers, it has two significant disadvantages, namely, its efficiency and the fact that the plane detected by RANSAC may not necessarily belong to the same object surface; that is, spurious surfaces may appear, especially in the case of parallel-gradual planar surfaces such as stairs. The innovative idea proposed in this paper is a modification for the RANSAC algorithm called Seq-NV-RANSAC. This algorithm checks the normal vector (NV) between the existing point clouds and the hypothesised RANSAC plane, which is created by three random points, under an intuitive threshold value. After extracting the first plane, this process is repeated sequentially (Seq) and automatically, until no planar surfaces can be extracted from the remaining points under the existing threshold value. This prevents the extraction of spurious surfaces, brings an improvement in quality to the computed attributes and increases the degree of automation of surface extraction. Thus the best fit is achieved for the real existing surfaces.  相似文献   

地下空间数据挖掘与虚拟现实     

何撼东  王心源  吴立 《测绘科学》2010,35(2):130-131,39

目前,地理信息系统处理空间数据多停留在点、线、面三类二维的地表数据,对离散或连续的真三维数据进行处理尚处于初步研究阶段。本文基于ArcGIS9.2版本中新开发的Extrude Between模块的拉伸封闭多边形面功能,以某校区地下87个离散钻孔数据为例,进行三维虚拟实现:首先,进行空间数据的挖掘,即对87个钻孔数据通过预处理,进行对具有特异值的各个钻孔数据层空间内插,生成具有深度属性的各层等高线,最终生成模拟各地层上表面形态的TIN;然后,虚拟实现真三维数据的可视化及体视化,达到对地下实体空间进行逼真模拟,反映该校区地形、地貌、地层分布以及水文地质特征。  相似文献   

基于MultiGen Creator/Vega的虚拟图书馆设计研究   总被引：2，自引：0，他引：2  

张冬有  臧淑英 《测绘与空间地理信息》2006,29(4):8-10

以虚拟图书馆为研究对象,利用MuhiGen Creator和Vega进行建模和系统设计。本文论述了在图书馆模型建立过程中层次结构模型、细节层次结构、实例技术和纹理贴图等技术的实现,以及使用Vega及其提供的API函数的系统开发方法。研究证明,采用MuhiGen Creator和Vega将虚拟现实技术与数字图书馆结合的方案可行．并具有较大的开发空间。  相似文献   

虚拟现实技术在城市规划中的应用研究与实践     

朱卫军  邹峥嵘  邹杰 《测绘与空间地理信息》2006,29(2):125-127

从虚拟现实的概念出发,分析了虚拟现实的3个特征,论述了虚拟现实技术涉及到的关键技术及虚拟现实技术在城市规划中的应用。最后,我们以小区为研究对象,将3D数据作为数据源,采用VRMap软件平台进行将VR技术应用于城市规划中的研究与试验。  相似文献   

多裂纹扩展的扩展有限元法分析   总被引：1，自引：0，他引：1  

石路杨  余天堂 《岩土力学》2014,35(1):263-272

建立了求解多裂纹扩展的扩展有限元法。引入裂纹交叉汇合加强函数以分析多裂纹交叉汇合过程;在裂纹附近区域使用广义形函数,并引入线增函数消除混合单元,可有效地提高裂纹附近的精度;用砂浆法（线段-线段接触法）结合增广型Lagrange乘子法处理裂纹段的接触条件,可以精确地模拟裂纹面约束,并方便地求解控制方程。算例分析了两方面内容：（1）计算交叉裂纹体的应力强度因子,结果表明提出的方法精度高;（2）模拟多裂纹扩展及交叉汇合过程,模拟的裂纹扩展路径与试验结果吻合得较好,表明了方法的可靠性。  相似文献   

企业三维仿真Web GIS系统的设计     

张留民  田耀勇 《地理空间信息》2004,2(1):18-19,50

随着Internet的发展和人们对各类信息需求的增加及企业面向社会提高知名度的需要,使得企业三维仿真WebGIS系统有着较为广泛的应用前景。文章探讨了利用VisualBasic等开发企业三维仿真webGIS系统的过程和方法。  相似文献   

Virtual reality and its application to slide annimation of landslide     

PANJianping YEHuanzhou 《地球空间信息科学学报》2004,7(2):153-156

A few researches adopt virtual reality in landslide. So it is significant to combine the physicsbased deformable method with the process simulation of a sliding landslide, this way the dynamic process of a going landslide can be simulated. The analysis of the dynamic law of landslide provides a foundation to forecast and make it realiable to foretell disasters. After recounting the condition of VR and landsliding body simulation, this paper puts forward simulating landslide by the physics-based deformable method. The method divides landsliding into deformable body and rigid one. The deformation of deformable body can be compute by DDA and FEM, and DDA fits the great deformation and FEM is good for the tiny deformation. This paper shows it is feasible to simulate the landslide animation by this method.  相似文献   

Design and implementation of a 3D ocean virtual reality and visualization engine     

CHEN Ge  LI Bo  TIAN Fenglin  JI Pengbo  LI Wenqing 《中国海洋大学学报(英文版)》2012,11(4):481-487

In this study,a 3D virtual reality and visualization engine for rendering the ocean,named VV-Ocean,is designed for marine applications.The design goals of VV-Ocean aim at high fidelity simulation of ocean environment,visualization of massive and multidimensional marine data,and imitation of marine lives.VV-Ocean is composed of five modules,i.e.memory management module,resources management module,scene management module,rendering process management module and interaction management module.There are three core functions in VV-Ocean:reconstructing vivid virtual ocean scenes,visualizing real data dynamically in real time,imitating and simulating marine lives intuitively.Based on VV-Ocean,we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to surface.Environment factors such as ocean current and wind field have been considered in this simulation.On this platform oil spilling process can be abstracted as movements of abundant oil particles.The result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive rendering.VV-Ocean can be widely used in ocean applications such as demonstrating marine operations,facilitating maritime communications,developing ocean games,reducing marine hazards,forecasting the weather over oceans,serving marine tourism,and so on.Finally,further technological improvements of VV-Ocean are discussed.  相似文献