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International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 5. Hakodate 1998
IMPACT ON 3D MODELLING FROM THE DESIGN OF A WEB-BASED 3D INFORMATION SYSTEM
Steffen LANDES
Institute for Photogrammetry and Remote Sensing
University of Karlsruhe
Englerstr. 7, 76135 Karlsruhe
E-mail: landes Q ipf.bau-verm.uni-karlsruhe.de
GERMANY
Commission V, Working Group V/3
KEY WORDS: 3D user interface, VRML, virtual environments, 3D modeling, information systems
ABSTRACT
By the immense spreading and frequent use of the World Wide Web a powerful new medium has been created. Ac-
companying this development integration of new technologies like Java and VRML made it possible to build distributed
client/server applications for the WWW.
These features had a vital influence on the design of the 3D campus information system of the Karlsruhe University. For
this purpose VRML is used to create a graphical front end. It's handling the dynamic display and exploration of 3D data
in real-time. Java is used for the communication between Web browser and VRML scene, and for the connection to the
database of the information system.
The 3D model of the physical scene — including buildings, streets, etc. of the campus — is created by the fusion of different
data sources. In context of this scene geometric representations of abstract data are also embedded. This is done by
using physical, real-world metaphors like signs, blackboards, etc. Thereby a significant aid to the user is given in terms of
comprehension, navigation, and exploration.
To use this scene as a 3D user interface new concepts — also considering cognitive aspects — are developed to model
and represent both types of 3D data. It is demonstrated that the modelling process is not a straight forward mapping of
real-world objects to 3D models and should consider the guidelines mentioned in the paper.
1 MOTIVATION
In the field of information systems a new type of user inter-
face will be established: it is the 3D user interface, which
allows the user to explore interactively a 3D data set in real
time.
This development has a vital influence on the design of the
3D campus information system of the Karlsruhe University.
The aim of this information system is to
e present the university world-wide,
e provide information for students, staff and visitors and
for
e the use as a planning tool.
For this purpose it is obvious to use common Internet stan-
dards. Therefore the information system is accessible in the
World Wide Web by a Web browser. In this Web browser
VRML (Virtual Reality Modeling Language) is used to pro-
vide an interactive real-time 3D interface. The connection
between a database management system and the user in-
terface is implemented in Java. Java (Arnold and Gosling,
1998) is also utilised to implement system-specific exten-
sions to the user interface. With these standards it is possi-
ble to realise a platform-independent system which is sup-
porting distributed client/server applications.
By fusion of different data sources the 3D model of the
physical scene (including buildings, streets, etc.) is cre-
ated. Geometric representations of abstract data are also
339
embedded in this scene by using physical, real-world meta-
phors like signs, blackboards, etc. This should give appro-
priate assistance to the user.
To support an easy and intuitive access to the information
inside the 3D scene, this graphical 3D user interface is fol-
lowing the object-action paradigm. This means that a point-
and-click interaction with the model of a real-world object
should first select this object and then perform an action on
it with an immediate visual feedback to the user. This is
why an object is caught in a dualism where it is used as
e a real-world object and
e a widget
at the same time. In the modelling process of a 3D scene
this dualism has an impact on the representation of the ob-
jects, which is leading to new design aspects with an great
influence on the modelling process.
2 COMPONENTS OF THE 3D CAMPUS
INFORMATION SYSTEM
The World Wide Web a powerful new medium. But the
Web is not only a great source of information, it is also in-
tegrating standards of the underlying delivery mechanism
(Rohrer and Swing, 1997). In this field the development
of new technologies like Java and VRML are supporting
distributed client/server applications for the Web. The ad-
vantage of the Web is also the interaction and navigation
