BIM 和GIS 的空间语义数据集成方法及应用研究

随着数字城市和智慧城市的建设发展,建筑信息模型(BIM)和地理信息系统(GIS) 的集成被广泛研究和应用。目前的集成研究主要是通用数据标准IFC 和CityGML 之间的空间和 语义转换,但由于应用领域和空间尺度等差异,存在信息错误和丢失、几何语义信息耦合度低、 应用拓展性差等问题。为此提出了一种兼顾三维实体对象和地理空间对象的三维城市数据模型, 研究了BIM 和GIS 的空间和语义数据的提取、处理和转换方法,设计了BIM 和三维GIS 的集 成应用框架并在三维可视化平台上进行验证和初步应用。该方法可实现BIM和GIS 信息在几何、 语义、精度上的完全融合,避免了传统的数据转换带来的信息缺失,在多尺度的空间和语义信 息分级存储和加载显示方面存在着优势,有利于实现大规模、高精度的建筑和城市信息的高效 集成。     

基于GIS+BIM的滇中引水工程数字场景构建研究

本文以云南省滇中引水工程为例,采用GIS+BIM数字化技术,对滇中引水工程数字化场景构建技术进行探索,旨在为长距离引调水工程的数字孪生底座构建提供可行的技术路径。通过GIS三维模型构建、BIM模型构建及模型集成的研究,对比了主流的GIS三维建模高精度数据的采集和处理技术,阐明了三维GIS大场景搭建、工程实景三维模型建立、多类型引水建筑物建模的方法,同时提出了工程数字化模型集成的成套技术路线,采用新一代三维驱动引擎,通过投影变换算法实现长距离不同工程坐标系下BIM模型在标准GIS球面场景中的无缝拼接,达到全线模型的集成,构建了工程三维应用的数字化基础,可为水利工程数字孪生建设抛砖引玉,提供建设指引。     

图形图像融合的海量建筑绘制

目的 城市3维模型数据海量且结构复杂,缺乏一个高效完善的可视化系统往往是影响数字城市应用的瓶颈之一。通常利用多层次细节（LOD）与调度算法减少每一帧绘制的数据量来提高绘制效率,当场景规模足够大时,即使采用复杂的优化算法也难以取得较好的效果。为此,本文在传统算法基础上,提出一种图形图像融合的海量建筑物场景绘制方法。方法 提出并采用视域分级绘制策略,将视椎体平行分割为感兴趣区域、次感兴趣区域和非感兴趣区域,感兴趣区域采用图形实时绘制方法,使用离屏渲染技术将次感兴趣和非感兴趣区域绘制在纹理图像中,每一帧绘制完成后将二者进行顾及深度信息的融合,实现完整场景渲染。结果 使用公开的纽约市区CityGML文件作为实验数据,数据包含了118 195个LOD1和LOD2级别的建筑物模型。分别构建多组不同建筑数量的场景进行帧率统计实验,绘制帧率都达到20帧/s以上。算法实现了视觉无损失的场景完整渲染,并与Cesium平台进行对比实验,证明算法有效且系统运行流畅。结论 图形图像融合的绘制方法,既保持了图形渲染的漫游连续性,同时也具有图像渲染的场景复杂度无关的优点。实验结果表明,针对大规模的低分辨率建筑模型场景,算法可以有效提高系统的渲染能力,在性能相对较低的硬件条件下也能实现海量建筑物实体模型的流畅漫游,并达到视觉无损失的场景完整绘制。     

情景式跨媒体数字城市系统

结合虚拟现实、GIS和跨媒体技术,提出一种具有高真实感、较强交互能力的情景式数字城市系统实现方法.该方法以GIS矢量数据为空间索引,全景交互式视频为表现内容,且加载文字、图像和音频等数据,并对这些海量信息进行跨媒体数据统一建模,以实现不同类型数据的组织和管理.与通过三维图形实现城市建模相比,采用文中方法实现的系统具有数据采集高效、表现手段真实感强、建模成本低和易于扩充等优势.     

多比例尺下的三维GIS细节层次可视化技术

In this paper ,by investigating leve!yof detail in 3D GIS,we integrate generalization techniqueswith 3D visualization techniques on the basis of object oriented database. In order to improve the perfor-mance of database access ,we investigate the access structure based on modified reactive tree and analyzethe detailed method of representing level of detail. This approach visualizes 3I) object with object-orient-ed database and integrates generalization with 3I) visualization techniques ,3D G-IS is expected to achievebetter performance of query and photo-realistic visualization at multi-scale。     

城区建筑物3D景观模型建立

为了在2D GIS基础上实现城市建筑物的3D显示,提出了一种建立建筑物3D模型的方法,该方法首先采用最大包围盒法将建筑物3D模型与2．5D DEM集成在一起,然后采用了Meier关系数据结构的表示城区建筑物几何模型中的拓扑信息和属性信息,并通过VRML浏览器业实现城市景观的交互显示,从而实现了利用常规2D GIS数据建立建筑物3D景观虚拟模型,实验结果表明,该方法能在VRML浏览器中以各种视角,在各个位置和按各种缩放比例,对建筑物模型进行动态观察,并在计算机屏幕上实现立体显示,根据实验结果和分析可见,随着2D GIS的发展成熟,利用常规2D GIS数据来建立建筑物3D景观模型的条件已经具备。     

3D landscape art design and network space reconstruction based on complex embedded system

Network space has gone beyond the map. Many critics claim that Geographic Information Systems (GIS) determines the environment. New geotechnical technologies such as embedded computer systems and tools, cyberspace network space reconstruction, and aerial photography allow network space to obtain large amounts of back-specified 3D data, but these 3D technologies are environmentally friendly. Help deal with positive criticism. Can connect GIS and 3D. It back-specifies the 3D model with basic data and adds a ground-based network space reconstruction to the traditional GIS aerial view. This proposed to place GIS and 3D in an index frame and wrap the environmental and network space elements using 3D GIS for the network space reconstruction of the new landscape archeological network space. 3D-models and displays in scene architectonic examination and plan. These scene models, close to drawings and guides, are urgent during plan examination and exploration by the scene engineering program. In this regard, models offer scene scientists and creators of various activity methods for visual reasoning and visual correspondence. This commitment investigates the different elements of (enlarged) models for scene designers, incorporating investigation, affirmation, union and introduction regarding use and cycle. It presents a typology of models depending on their exhibition (instrumental use), exemplified by a few cases. Even though the attention here is on the function of models in scene engineering, the contention created in this paper is additionally pertinent to the firmly related controls of engineering and metropolitan plan and accordingly replaceable.     

复杂三维空间对象的模型可视化研究

针对数字城市三维GIS系统中建筑物复杂三维对象的描述提出了一种结合LOD(Level of detail)可视化能力的三维数据模型,并对该模型的构成机理,在三维空间中可视化过程作了详细分析,并通过原型系统对其进行了验证。     

High-resolution 3D spatial modelling of complex geological structures for an environmental risk assessment of abundant mining and industrial megasites

Conceptual geological models of industrial and mining megasites are an essential task of groundwater investigations as well as environmental risk assessment studies. Therefore, the conceptualization process of the structural geological model has depended on the development of a set of 2D cross-sections to portray a 3D picture of groundwater flow. This attempt always includes some simplifications that require, only to some extent, the true 3D situation of heterogeneous aquifers. Consequently, the modelled predictions of the path flow and transport conditions of contaminated groundwater are not satisfying in terms of a flow-path and risk based modelling approach. A more structured approach to develop the hydrogeological framework for the conceptual model is advocated, using different 3D geological modelling software packages to assemble the data, working in three dimensions and using this platform for subsequent groundwater flow modelling. Attention is given to the capability of different 3D modelling approaches, indicated by geostatistically based versus constructive cross-section based interpolations of complex sedimentary successions, that are compared in their results and suitability for subsequent hydrogeological modelling requirements.The paper describes the results, in high-resolution 3D modelling, of the complex geological environment of the Bitterfeld/Wolfen megasite in the eastern part of Germany. Identification, assessment, and remediation of large-scale groundwater contamination require a detailed knowledge of the heterogeneous geological structure to predict the fate and pathways of contaminants and their potential interaction with, e.g., surface water. An area of 16 km² of the model area of the Bitterfeld/Wolfen area was chosen to transfer the complex structural geological setting. The subsurface geology could be assigned to 31 lithostratigraphic units and depicted using a 10×10 m GIS grid. This constructive and “knowledge-driven” 3D modelling allows the prediction of vertical and horizontal sections, visualization purposes, volumetric calculations of distinct sedimentary units, GIS applications, and the use of the detailed digital information within the subsequent flow and transport groundwater modelling. The high-resolution digital 3D model improves the hydrogeological modelling results. It is considered a basic requirement for groundwater modelling and investigations on environmental risk and impact assessment by fate, and pathway exposure route analysis of the complex geological and groundwater situations.     

3D radiative transfer modelling of fire impacts on a two-layer savanna system

We present a new, detailed three dimensional (3D) approach to modelling the pre- and post-fire reflectance of a two-layer savanna system modelled as heterogeneous overstory (tree) and understory (grass) layers. The models were developed from detailed field measurements of structural and radiometric properties made at experimental burn plots with varying canopy cover in the Kruger National Park, South Africa. The models were used to simulate 400-2500 nm spectral reflectance at 10-500 m spatial scale for various viewing and solar geometry configurations. The model simulations closely matched pre-fire and post-fire ground-based, helicopter and satellite remote sensing observations (all r² values > 0.95 except one post-fire case). The largest discrepancies between modelled and observed reflectances occurred typically at wavelengths greater than 1200 nm for the post-fire simulations. The modelling results indicate that representation of overstory and understory structure and scattering properties are required to represent the burn signal in a typical savanna system. The described 3D modelling approach enables separation of the scattering contributions of the different scene components and is suited to testing and validating fire impact assessment algorithms at locations where the difficulty of obtaining both pre- and post-fire observations is a severe constraint.     

ArcGIS实现三维燃气管网仿真的研究

三维GIS能够较准确和高效地实现燃气管网的设计和管理,由此探讨了ArcGIS实现三维燃气管网的仿真.从数字高程和数字地形三维建模生成周边环境,到应用三维管线设计技术生成管网矢量数据,介绍了三维管线仿真环境建模原理,以及使用ArcGIS实现三维燃气管网仿真的系统层次结构和功能扩展,并且应用实例,展示系统设计开发的可行性和实际应用效果.     

基于多尺度时间递归神经网络的人群异常检测

如何在人群密度大、变化快、存在大量遮挡的密集场景中实现可靠的人群事件检测,是领域研究的难点和热点.在密集场景时空建模的基础上提出了一种基于多尺度时间递归神经网络的人群异常事件检测和定位方法.首先对人群场景进行网格化划分,并利用多尺度光流直方图对每个网格的人群动态进行刻画;然后,连接各个局部的人群动态获得整体的人群动态,实现整体人群动态的时间序列建模;最后,利用多尺度时间递归神经网络实现异常事件的检测和定位.其中,多尺度隐含层实现了密集场景中不同规模相邻网格之间的空间联系,节点间的反馈关系则为时间维度上的关系表达提供了有效方案.与多种代表性算法的对比实验,验证了本方法的有效性.     

An integrated VR–GIS navigation platform for city/region simulation

This paper introduces a virtual city oriented VR–GIS platform which synthesizes several latest information technologies including virtual reality, 3D geographical information system, remote sensing, and multi‐dimensional visualization. The platform is a seamless integration of VR functions and GIS analysis methods, which can be used to organize and present massive spatial data. It also supplies 3D spatial analysis functions, 3D visualization for spatial process and natural simulation, and serves as an engine platform for digital city. Copyright © 2009 John Wiley & Sons, Ltd.     

Scene-Aware 3D Multi-Human Motion Capture from a Single Camera

In this work, we consider the problem of estimating the 3D position of multiple humans in a scene as well as their body shape and articulation from a single RGB video recorded with a static camera. In contrast to expensive marker-based or multi-view systems, our lightweight setup is ideal for private users as it enables an affordable 3D motion capture that is easy to install and does not require expert knowledge. To deal with this challenging setting, we leverage recent advances in computer vision using large-scale pre-trained models for a variety of modalities, including 2D body joints, joint angles, normalized disparity maps, and human segmentation masks. Thus, we introduce the first non-linear optimization-based approach that jointly solves for the 3D position of each human, their articulated pose, their individual shapes as well as the scale of the scene. In particular, we estimate the scene depth and person scale from normalized disparity predictions using the 2D body joints and joint angles. Given the per-frame scene depth, we reconstruct a point-cloud of the static scene in 3D space. Finally, given the per-frame 3D estimates of the humans and scene point-cloud, we perform a space-time coherent optimization over the video to ensure temporal, spatial and physical plausibility. We evaluate our method on established multi-person 3D human pose benchmarks where we consistently outperform previous methods and we qualitatively demonstrate that our method is robust to in-the-wild conditions including challenging scenes with people of different sizes. Code: https://github.com/dluvizon/scene-aware-3d-multi-human     

数字化三维城市设计建模技术分析

三维数字地图具有动态性、交互性、超媒体集成、多尺度表达、多维化显示等优越特性。根据地图信息来还原实际地形地貌,显示地形地貌的微缩三维地形模型是GIS的一个重要的研究课题,数字化城市中三维景观的构建是一项具有广阔应用前景的技术。该文系统论述了三维城市模型建立的基本理论与关键技术。     

GIS-based decision support for solar energy planning in urban environments

This paper describes the development of a solar energy planning system, consisting of a methodology and decision support software for planners and energy advisers. Intended primarily to predict and realise the potential of solar energy on an urban scale, the system will support decisions in relation to the key solar technologies: solar water heating, photovoltaics and passive solar gain. The prototype discussed here relates to the first of these. Based on a methodology for predicting the solar energy potential of domestic housing stock, it is implemented as a relational database application linked to a customised geographical information system (GIS). The methodology takes into account baseline energy consumption and projected energy saving benefits. To support this, the system incorporates a domestic energy model and addresses the major problem of data collection in two ways. Firstly, it provides a comprehensive set of default values derived from a new dwelling classification scheme that builds on previous research. Secondly, novel GIS tools enable key data to be extracted from digital urban maps in different operational modes. The paper concludes with a discussion of possible planning scenarios to illustrate how the system may be deployed at various levels of granularity to assist targeting of individual properties or city neighbourhoods, or for whole-city projections.     

地物提取的多尺度特征遥感应用分析

通过空间尺度效应分析,阐述不同属性景观地物在同一分辨率或同一尺度影像中提取的不合理性。为获得精确的地表信息,提出多尺度遥感影像分析方法,解决不同地物在不同空间尺度影像数据中提取的难题。通过多种分辨率影像的多尺度影像信息提取的应用实践,分析地物提取中的多尺度特性、尺度与分辨率关系等。     

大规模城市三维景观实时浏览解决方案研究及实现

如何实现大规模城市三维景观实时快速浏览是城市景观可视化中的关键问题之一。主要从空间数据组织、管理、调度方面讨论了这一问题,给出了以多层次细节模型简化技术和动态可见裁剪技术为主要技术的解决方案,最后介绍了一个开发城市三维景观实例系统M3DVIEW。     

GIS数据融合的虚拟现实系统探讨

针对现有三维GIS系统以及虚拟现实系统存在的问题,基于可动态更新GIS数据开发了具备三维场景漫游、外部数据库查询和部分空间分析功能的虚拟现实系统。该文首先介绍了地理信息系统和虚拟现实的现状及其融合发展的背景,然后描述了在Visual VC＋＋．NET开发环境及OpenGL函数库的基础上,利用Terra Vista、MuhiGen Creator及Vega等仿真建模、实时渲染工具建造系统的过程,并以“数字都江堰演示系统”的建设证实了其实用效果。     

GeoVR: a web-based tool for virtual reality presentation from 2D GIS data

A tool called GeoVR has been designed and developed under a client/server architecture to enable the interactive creation of a 3D scene and virtual reality modeling language (VRML) model from 2D spatial data by integrating Internet geographical information system (GIS) and HTML programming. The client front-end of this tool provides an HTML form to set properties for building 3D scenes, while the server back-end supported by off-the-shelf software: ArcView Internet Map Server and ArcView 3D Analyst through Avenue programming, processes the parameters and generates a 3D scene. This 3D scene is then transformed into a VRML model, which, together with its legend, is sent back to the VRML-enabled WWW browser for display and navigation. It is demonstrated that this tool, not only automates the conversion of the conventional 2D GIS data into VRML, but also adapts the current GIS 3D capabilities to the increasingly popular Web environment. The development of GeoVR offers new opportunities for geoscientists to build applications that benefit from virtual reality presentation based upon the existing GIS spatial databases.