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MODELING AND VISUALIZING 3D URBAN ENVIRONMENT VIA INTERNET FOR
URBAN PLANNING AND MONITORING
Guoging Zhou*, Zhenyu Tan“, Pen
c
e b = : 2
gen Cheng”, and Weirong. Chen”
“Old Dominion University, Kaufman Hall, Rm. 214, Norfolk, VA 23529, USA-gzhou@odu.edu
b er 5 à a = NI . a i t.
Department of Surveying Engineering, East China Institute of Technology, Fuzhou, Jianxi 344000
ISPRS Commission Il/6
KEYWORDS: Three-dimensional, GIS, city, modeling, visualization, internet/web
ABSTRACT:
Geographical Information System (GIS) technology has been an important tool in supporting urban planning and management for
efficient accessibility to more, better, and timely information. This paper presents our research results of visualizing 3D city model
in a web explorer environment under the supports of digital building model (DBM), digital terrain model (DTM), large-scale true
urban orthoimage, and actual building sidewall pictures. A system has initially been designed and developed under a client/server
architecture, which integrates Internet GIS with multi-tier web application for creation of a 3D city model. The front-end client
provides a user interface for setting properties of the 3D model, while the backend server processes the parameters and generates the
3D model, which is then sent back to the VRML-enabled WWW browser for display and navigation. The technology for display and
navigation of the 3D model is actually a Java JSP/Servlet technology built under multi-tier web architecture. The data accessing and
processing of the technology is through Java programming language to link the displayer with the database where the required GIS
spatial data are stored. The results from our experiment demonstrated that this developed architecture is able to display and visualize
3D city data in web environment for public access. Using the sidewall pictures taken from real city buildings, we refill the white
walls of urban buildings into a real appearance as seen in our real world city. The player provides several click buttons to change the
effect and position of visualization, including rotation, zoom, pan, seek etc. The users can easily to view details of specific building,
the entire city in a moving 3 dimensions, to locate a specific building, and so on.
1. INTRODUCTION
The urban GIS plays an important role in city planning,
communication system design, micro-climate control and
simulation, tourism, etc. The demand for visualization of urban
model and realistic presentation of the real world has been
increased dramatically today. Internet and World Wide Web
(WWW) have been widely applied in delivering, processing,
and publishing geospatial data. Web-based GIS, which permits
users to access, retrieve, display, and analyze geospatial data
over the web, has got a wide variety of applications. In the
recent years, web-based three-dimensional (3D) GIS for
visualizing geospatial data has attracted many researchers. The
operation uses the web as a delivery mechanism, deals with the
transformation of —multi-dimensional ~~ geospatial data,
information, and knowledge into an effective 3D visual form
(Lin et al, 1999; Belfore ef al., 2003; 2002; 2001; Blaser et al.
2000; Kreuseler, 2000). MacEachren (1997) used VRML 2.0 to
model geospatial data, and Java to develop an interface to
interact with the VRML world. Hibbard (1998) designed and
developed the VisAD system, which enables many users to
implement the visualization of a shared set of numerical data
and computation sources. Lin et al. (1999) and Huang er al.
(1999) developed a called GeoVR system, which is a
client/server architecture to enable the interactive creation of a
3D scene and VRML model from 2D spatial data by integrating
internet GIS and HTML. Rohrer and Swing (1997) suggested
the use of traditional approaches for visualization because of
web-based inherent limitation in, such as, the narrow channel
of the Internet. Verbree et al. (1999) presented an interaction in
virtual world views between 3D GIS and virtual reality (VR).
This paper presents our research results on development of a
web-based urban 3D visualization. Using downtown Denver
CO as protocol, the orthoimage is employed as a bottom layer,
and objects are superimposed. The system has been designed
and implemented under a client/server architecture, which
integrates Internet GIS with multi-tier web application for
creation of a 3D city model. The front-end client provides a
user interface for setting properties of the 3D model, and the
back-end server processes the parameters and generates a 3D
city model, which is then sent back to the VRML-enabled
WWW browser for display and navigation. The display and
navigation of the 3D city model is implemented using a Java
JSP/Servlet technology built under a multi-tier web
architecture. The data processing is implemented through Java
programming language, and the data accessing is carried out
via linking the displayer to the database, in which the required
GIS spatial data are stored.
2. ARCHITECTURE OF WEB-BASED URBAN 3D GIS
The architecture of web-based 3D city visualization is designed
in Figure 1. The architecture consists of three-tiered modules.
The first tier is to display layers that includes both the web
browser and the web server, which is responsible for
assembling the data into a presentable format. The second tier
is the application layer. It consists of scripts and programs. The
third tier provides the second tier with the data needed. The
architecture operates as follows:
(1) Collect data from the user (the first tier),
