FAST PRODUCTION OF VIRTUAL REALITY CITY MODELS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

3D city model is a digital representation of the Earth"s surface and it"s related objects such as Building, Tree, Vegetation, and some manmade feature belonging to urban area. There are various terms used for 3D city models such as "Cybertown", "Cybercity", "Virtual City", or "Digital City". 3D city models are basically a computerized or digital model of a city contains the graphic representation of buildings and other objects in 2.5 or 3D. Generally three main Geomatics approach are using for Virtual 3-D City models generation , in first approach , researcher are using Conventional techniques such as Vector Map data, DEM, Aerial images , second approach are based on High resolution satellite images with LASER scanning, In third method , many researcher are using Terrestrial images by using Close Range Photogrammetry with DSM & Texture mapping. We start this paper from the introduction of various Geomatics techniques for 3D City modeling. These techniques divided in to two main categories: one is based on Automation (Automatic, Semi-automatic and Manual methods), and another is Based on Data input techniques (one is Photogrammetry, another is Laser Techniques). After details study of this, finally in short, we are trying to give the conclusions of this study. In the last, we are trying to give the conclusions of this research paper and also giving a short view for justification and analysis, and present trend for 3D City modeling. This paper gives an overview about the Techniques related with "Generation of Virtual 3-D City models using Geomatics Techniques" and the Applications of Virtual 3D City models. Photogrammetry, (Close range, Aerial, Satellite), Lasergrammetry, GPS, or combination of these modern Geomatics techniques play a major role to create a virtual 3-D City model. Each and every techniques and method has some advantages and some drawbacks. Point cloud model is a modern trend for virtual 3-D city model. Photo-realistic, Scalable, Geo-referenced virtual 3-D City model is a very useful for various kinds of applications such as for planning in Navigation, Tourism, Disasters Management, Transportations, Municipality, Urban Environmental Managements and Real-estate industry. So the Construction of Virtual 3-D city models is a most interesting research topic in recent years.

Transactions in GIS, 2006

A VR (virtual reality) simulator which is used for helicopter simulations requires a virtual environment of real world urban areas. However, real urban environments are continuously changing. It is necessary to develop a modeling method that makes direct use of GIS (geographical information system) data which is updated periodically. A flight simulation needs to visualize not only buildings in the near distance but also a large number of buildings in the far distance. We propose a method for modeling urban environments from aerial images and digital maps with relatively little manual work. An image-based method is applied to the urban modeling that considers the characteristics of Korean cities. Buildings in the distance can be presented without creating a large number of polygons. The proposed method consists of a pre-processing stage that prepares the model from the GIS data and a modeling stage that creates the virtual urban environment. The virtual urban environment utilizes the height map of buildings.

Licensed effective tool for physical planning(e infrastructure and transportation planni interactive computer graphics application (three dimensions) are central to enabling presentation and manipulation of geograp maps are used by GIS specialists as tools fo spatial data to non-experts. Recently, the systems, 3D computer graphics and 3D emerged with reality. most of the 3D GIS a to focus on visualization such as walk-throu scenic simulations. The 3D data model is re to express the 3D objects in reality. Th models consisting of the geometry and t surfaces could aid applications such as urb heritage conservation. A standard techniqu large-scale city models automatically or sem is to apply stereo vision on aerial or satell city models are digital representations of the and related objects belonging to urban ar factories, buildings etc.). Several discipl

Within this article a procedure for the automatic generation of 3D city models is presented. For that purpose existing ground plans provided from a 2D GIS and height data measured by airborne laser scanning are combined. The presented approach can be applied for a fully automatic reconstruction of an urban model, for interactive control and correction of these automatically generated results and for a semi-automatic data capture. The results are 3D CAD models of the buildings. By an optional mapping of terrestrial or aerial images onto the reconstructed facades, virtual city models can be generated.

Developing realistic 3D models of cities provides designers, planners, the public, and the others with imagery closely coupled with the human expertise. This paper continues on the results of an earlier innovation in the field of texture creation for the construction of Virtually Realistic Model (VRM) of buildings in urban areas. Using a CCD camera mounted on a theodolite the system takes the images of building facades; and using a number of automated/semi-automated tools converts them into textures. The textures will then be applied to the CAD models of buildings obtained from aerial photographs. Having reviewed the components of the system, the paper reports on the development of a new On-Demand Measuring Tool (ODMT). The results show that, using such system can greatly improve the speed of realistic modelling of buildings in urban areas.

1 ABSTRACT There are several projects aimed at creating the 3D virtual city models for bigger cities all over the world. In order to bring these models closer to smaller cities to be used e.g. in urban planning or regional development the trade-off between cost and quality of the model should be solved. From this point of view we discuss the input data available at low cost, the relatively simple work flow in creating the model and the quality parameters of the final model. We discuss the low cost input data such as DTM and terrestrial images taken with ordinary digital cameras with special focus on the cadastral data providing the building footprints that can be used for reconstruction. The simple work flow includes the data-processing providing the block flat-roof model and also the silhouette based building reconstruction method. Special focus in the work flow is given to relatively simple texturing and rendering to obtain the photorealistic large scale model. The quality paramet...

Due to the rapid developments in the field of computer graphics tools allowing for the real time visualisation of complex 3D data are becoming available also for standard applications. One example is the visualisation of urban landscapes within GIS. This type of application additionally profits from the fact, that meanwhile the required urban models can be collected area covering and efficiently based on aerial data like stereo images or LIDAR. Nevertheless, the requirements for data collection are still increasing due to the current spread of visualisation applications. One example is the generation of realistic visualisations from pedestrian viewpoints. In such a scenario the viewpoint restrictions of airborne platforms do not allow for the collection of sufficient image texture and geometric detail for the facades of the buildings. Since this information is required to guarantee a good visual appearance of the urban model from pedestrian perspectives, additional data has to be pr...

Lecture Notes in Geoinformation and Cartography, 2009

Abstr act: Visual Information Systems for urban planning can be produced in a variety of ways. In this paper we give an account of research into integrating scanned data with urban data sets to produce 3D applications that span built environment spatial scales from building elements to the whole city. In our research, 3D laser scanner is used to capture 3D building models as a way of developing visual 3D presentations. In order to use 3D building models for urban environment, relevant standards are reviewed and the integration of 3D building models with urban scaled geo-spatial data are explored. In the recent EU-funded IntelCities (2004)(2005) and Virtual Environment Planning System (VEPS, 2004(VEPS, -2008 research projects, the authors have worked on capturing an existing building in digital form and using 3D data in building refurbishment projects and visualisation of urban environment in planning consultation. The paper introduces the ways of producing 3D applications using integrated data from 3D scanning with geo-spatial datasets. The

Geo-spatial Information Science, 2003

Airborne laser scanner is an integrated system of GPS, INS and laser scanner. It has become an accurate, fast, and versatile measurement technique that can complement or partly replace other existing acquisition technologies and has been used in more diverse applications that concern large-scale and precise topographic Digital Elevation Models (DEMs) and Digital Surface Models (DSMs). Up to now, development of algorithm and methods for acquiring 3D spatial data, interpretation and modeling of this kind data for property application are main research topics. This paper demonstrates an experiment on generation of 3D virtual geographic environment by using experimental flight laser scanning data, based on a set of algorithms and methods that were developed for automatically interpret range images for extracting geo-spatial features to reconstruct geo-objects. The set of algorithms and methods for interpretation and modeling of laser scanner data include the followings: Triangulated Irregular Network (TIN) based range image interpolation; Mathematical Morphology (MM) based range image filtering, feature extraction and range image segmentation, feature generalization and optimization; 3D objects reconstruction and modeling; Computer Graphics (CG) based visualization and animation of geographic virtual reality environment. The results of the experiment of this research demonstrate the operational utilization of the suggested approach and its applicability to various fields of study, such as urban disaster management.