World Transactions on Engineering and Technology Education © 2004 UICEE
Vol.3, No.1, 2004
11
INTRODUCTION
Traditional methods of educating students have well-proven
advantages, but some deficiencies have also been detected. A
typical problem has been how to engage students with
appropriate information and communication technologies
(ICT) during the learning process. In order to implement
innovative interactive communication and learning paradigms
with students, teachers should make innovative use of new ICT
[1]. Although multimedia material is provided in a number of
formats, including textual, images, video animations and aural,
educational systems are not designed according to current
teaching and learning requirements. That requirement is to
efficiently integrate these formats in well-proven means, eg
through the Web. The system described here does this by
introducing Web3D, virtual and augmented reality (AR) in the
same Web-based learning support application.
Research into educational systems associated with the use of
Web3D technologies is very limited. Web3D has the potential
for a number of different applications ranging from 2D to 3D
visualisation [2]. One of the most appropriate means of
presenting 2D information is through the WWW Consortium
[3]. On the other hand, a promising and effective way of 3D
visualisation is AR, which combines computer-generated
information with the real world, and it can be used successfully
to provide assistance to the user necessary to carry out difficult
procedures or understand complex problems [4].
An overview of existing AR systems in education and learning
has been presented elsewhere [5]. A more recent educational
application is an experimental system that demonstrates how to
aid teaching undergraduate geography students using AR
technologies [6]. An educational approach for collaborative
teaching targeted at teachers and trainees that makes use of AR
and the Internet has been illustrated by Wichert [7].
An educational system is presented here for improving the
understanding of the students through the use of Web3D and
AR presentation scenarios. An engineering and design
application has been experimentally designed to support the
teaching of mechanical engineering concepts such as machines,
vehicles, platonic solids and tools. It should be noted that more
emphasis has been given to the visualisation of 3D objects
because 3D immediately enhances the process of learning. For
example, a teacher can explain what a camshaft is using
diagrams, pictures and text, etc. However, it still may be
difficult for a student to understand what a camshaft does. In
the current system’s Web3D pictures, text and 3D model
(which can be animated) are visualised so that the student can
manipulate and interact with the camshaft, and also see other
related components such as the tappets, follower, etc, arranged
as they might be with an engine.
In this article, the authors present four example themes to
support the teaching of engineering design. These four themes
may represent different courses or different teaching sessions
as part of the same course. The remainder of this article
describes the requirements for augmented learning, provides a
brief discussion of the presented system’s architecture, and
illustrates how the system might be used to support teaching
processes using Web3D and AR technologies. Finally,
conclusions are made and future work suggested.
THE REQUIREMENTS OF AUGMENTED LEARNING
The requirements for virtual learning environments have been
already well defined [8]. However, in AR learning
environments, they have not been systematically studied. In
general, any educational application requires technological,
pedagogical and psychological aspects to be carefully
investigated before their implementation [9]. Especially when
introducing new technologies, such as Web3D and AR into the
Web3D and augmented reality to support engineering education
Fotis Liarokapis, Nikolaos Mourkoussis, Martin White, Joe Darcy, Maria Sifniotis, Panos Petridis,
Anirban Basu & Paul F. Lister
University of Sussex
Falmer, England, United Kingdom
ABSTRACT: In the article, the authors present an educational application that allows users to interact with 3D Web content
(Web3D) using virtual and augmented reality (AR). This enables an exploration of the potential benefits of Web3D and AR
technologies in engineering education and learning. A lecturer’s traditional delivery can be enriched by viewing multimedia content
locally or over the Internet, as well as in a tabletop AR environment. The implemented framework is composed in an XML data
repository, an XML-based communications server, and an XML-based client visualisation application. In this article, the authors
illustrate the architecture by configuring it to deliver multimedia content related to the teaching of mechanical engineering. Four
mechanical engineering themes (machines, vehicles, platonic solids and tools) are illustrated here to demonstrate the use of the
system to support learning through Web3D.
12
education process, many aspects need to be considered. The
authors have classified some of the most important issues that
are involved in AR learning scenarios.
To begin with, the educational system must be simple and
robust and provide users with clear and concise information.
This will increase the level of students’ understanding and their
skills. Moreover, the system must provide easy and efficient
interaction between the lecturer, students and the teaching
material. Apart from these issues, the digitisation of the
teaching material must be carried out carefully so that all of the
information is accurately and clearly presented to users. This
digitisation or content preparation is usually an offline process
and consists of many different operations, depending on the
target application.
The authors believe that a combination of Web3D and AR
technologies can help students explore the multidimensional
augmentation of teaching materials in various levels of detail.
Students can navigate through the augmented information and,
therefore, concentrate and study in detail any part of the
teaching material in different presentation formats, thus
enhancing understanding. With Web3D environments
traditional teaching materials may be augmented by high
quality images, 3D models, single- or multi-part models, as
well as textual metadata information. An image could be a
complex diagram, a picture or even a QuickTime movie. The
3D model allows the student to understand aspects of the
teaching material that is not evident in the pictures, because
they are hidden. Finally, metadata can provide descriptive
information about the teaching material that cannot be provided
by the picture and the 3D model.
SYSTEM ARCHITECTURE
The system presented here can be used to create and deliver
multimedia teaching material using Web3D and AR
technologies. The authors have already demonstrated this in
other application domains, such as virtual museum exhibitions
[10]. The architecture of this system is based on an
improvement of the researchers’ previously defined three-tier
architecture [11]. The architecture, as shown in Figure 1,
consists of content production, a server and visualisation
clients.
Figure 1: The three-tier architecture.
The first tier is the content production side, which consists of
the content acquisition process – content can consist of 3D
models, static images, textual information, animations and
sounds – and a content management application for XML
(CMAX) that gathers content from the file system and
packages this content into an XML repository called XDELite.
In the example illustrated in this article, most of the 3D models
utilised were downloaded from the Internet [12]. This is quite
important, because teachers should make best use of freely
available content because generating 3D content can be
expensive and time consuming.
The server side tier is based on XML and Java-Servlet
technologies. The Apache Tomcat server was used and was
configured with a Java Servlet, named the ARCOLite XML
Transformation Engine (AXTE) [10]. The purpose of this
server is to respond to user requests for data, stored in the
XDELite repository, and dynamically deliver this content to
the visualisation tier. XSL stylesheets are then utilised to
render the content to the visualisation clients.
The client visualisation tier consists of three different
visualisation domains, namely: the local, the remote and the
AR domains. The local domain is used for delivering
supporting teaching material over a Local Area Network
(LAN), while the remote domain may be used to deliver the
same presentations over the Internet, both utilising standard
Web browsers.
The AR domain allows the presentation of the same content in
a tabletop AR environment [10]. The authors have developed
an application called ARIFLite that consists of a standard Web
browser and an AR interface integrated inside a user friendly
visualisation client built from Microsoft Foundation Class
(MFC) libraries. The software architecture of ARIFLite is
implemented in C++ using an Object-Oriented (OO) style.
ARIFLite uses technologies, such as ARToolKit’s tracking and
vision libraries [13] and computer graphics algorithms based in
the OpenGL API [14]. The only restriction of the AR system is
that the marker cards and the camera are always in line of sight
of the camera.
USER OPERATION
The user, eg a student, accesses this system simply by typing a
URL into a Web browser that addresses the index page of the
presentation or launches the presentation from a desktop icon.
In this case, the student will be accessing a Web3D
presentation with 3D, but no AR view (see Figure 2), which
illustrates the Web browser embedded in ARIFLite. This is the
mode of operation for the Internet.
For local Web and AR use, eg in a university laboratory
environment or a seminar room, the student would launch
ARIFLite from an icon on the PC desktop. By using ARIFLite,
the student can browse multimedia content as usual, but also
extend the 3D models into the AR view. Switching to AR view
causes the Web browser to be replaced with a video window in
which the 3D model appears. The user can then interact with
the 3D model and can compare it to real objects in a natural
way, as illustrated in Figure 5.
WEB3D PRESENTATION
Demonstration in seminars and lecture rooms is one of the
most effective means of transferring knowledge to groups of
13
people. One of the capabilities of the presented system is to
increase the level of understanding of students through
interactive Web3D and AR presentation scenarios. The lecturer
can control the sequence of the demonstration using the
visualisation client [10]. One can imagine a group of students
and the lecturer gathered around a table on which there is a
computer and large screen display. The virtual demonstration
starts by launching a Web browser (ie Internet Explorer) or
ARIFlite. Figure 2 actually illustrates the Web browser
embedded in ARIFLite.
Figure 2: Web browser embedded in ARIFLite showing the
presentation’s homepage.
Figure 5: AR visualisation of a piston.
On the homepage, the user has the option to choose between
four different supporting material themes, namely: platonic
solids, tools, machines and vehicles. Each module contains a
list of thumbnails representing links to relevant sub-categories,
as shown in Figure 3.
Next, the user can access more specific information about any
of the existing sub-categories. For example, in Figure 4, the
user has clicked on the camshaft, which accesses a new Web
page showing a thumbnail (that could access a larger picture or
a QuickTime movie), description of the camshaft and an
interactive 3D model displayed in an embedded VRML
browser. At this stage, the lecturer can describe the underlying
theory of a camshaft while interacting with the 3D model, eg
rotating, translating or scaling the model.
Figure3: Selection of machines.
Figure 4: Web3D visualisation.
Augmenting a Web-based presentation with 3D information (as
shown in Figure 4) can enhance student understanding and
allow the lecturer to present material in a more efficient
manner.
AUGMENTED REALITY PRESENTATION
By using ARIFLite, the authors could now extend the Web3D
presentation into a tabletop AR environment. AR can be
extremely effective in providing information to a user dealing
with multiple tasks at the same time [15]. With ARIFLite, users
can easily perceive visual information in a new and exciting
way. In order to increase the level of understanding of the
teaching material, 3D information is presented on the tabletop
in conjunction with real objects. Figure 5 shows an AR view of
a user examining a virtual 3D model of camshaft arrangement
in conjunction with a set of real engine components.
Similarly with the system demonstrated by Kato et al, users can
physically manipulate the marker cards in the environment by
14
just picking the markers and moving them into the real world
[16]. In this way, students are able to visualise how a camshaft
is arranged in relation to other engine components and examine
the real components at the same time. Users can interact with
the 3D model using standard I/O devices, such as the keyboard
and the mouse.
In order to manipulate better the 3D model, haptic interfaces,
such as 3D mouse (ie SpaceMouse XT Plus), are integrated
within the system. The SpaceMouse provides an 11-button
menu and a puck allowing six degrees of freedom, which gives
a more efficient interface than the keyboard [17]. The user can
zoom, pan and rotate virtual information as naturally as if they
were objects in the real world.
CONCLUSION AND FUTURE WORK
In this article, a simple and powerful system for supporting
learning based on Web3D and AR technologies is presented.
Students can explore a 3D visualisation of the teaching
material, thus enabling them to understand more effectively
through interactivity with multimedia content. It is believed
that the presented experimental scenarios can provide a
rewarding learning experience that would be otherwise difficult
to obtain.
In the future, the authors plan to create more educational
templates and add further multimedia content for the XML
repository so as to apply the system in practice. In order to
optimise the system’s rendering capabilities, greater realism
will be added into the augmented environment using
augmented shadows. Finally, more work needs to be conducted
in improving human-computer interactions by adding haptic
interfaces so that the system will have a more collaborative
flavour.
ACKNOWLEDGEMENTS
This research was partially funded by the EU IST Framework
V programme, Key Action III-Multimedia Content and Tools,
Augmented Representation of Cultural Objects (ARCO)
project IST-2000-28366.
REFERENCES
1. Barajas, M. and Owen, M., Implementing virtual learning
environments: looking for holistic approach. Educational
Technology and Society, 3, 3 (2000).
2. Web3d Consortium (2004), http://www.web3d.org
3. World Wide Web Consortium (2004), http://www.w3c.org
4. Schwald, B. and Laval, B., An augmented reality system
for training and assistance to maintenance in the industrial
context. J. of WSCG, Science Press, 1 (2003).
5. Liarokapis, F., Petridis, P., Lister, P.F. and White, M.,
Multimedia Augmented Reality Interface for E-learning
(MARIE). World Trans. on Engng. and Technology Educ.,
1, 2, 173-176 (2002).
6. Shelton, B.E. and Hedley, N.R., Using augmented reality
for teaching earth-sun relationships to undergraduate
geography students. Proc. 1st
IEEE Inter. Augmented
Reality Toolkit Workshop, Darmstadt, Germany (2002).
7. Wichert, R., A mobile augmented reality environment for
collaborative learning and teaching. Proc. World Conf. on
E-Learning in Corporate, Government, Healthcare and
Higher Education (E-Learn), Montreal, Canada (2000).
8. Dillenbourg, P., Virtual learning environments. Proc. EUN
Conf. 2000, Workshop on virtual environments (2000).
9. Kaufmann, H., Collaborative augmented reality in
education. Proc. Imagina 2003 Conf. (Imagina03),
Monaco (2003).
10. White, M., Liarokapis, F., Mourkoussis, N., Basu, A.,
Darcy, J., Petridis, P. and Lister, P.F., A lightweight XML
driven architecture for the presentation of virtual cultural
exhibitions (ARCOLite). Proc. IADIS Inter. Conf. on
Applied Computing 2004, Lisbon, Portugal, 205-212
(2004).
11. Liarokapis, F., Mourkoussis, N., Petridis, P., Rumsey, S.,
Lister, P.F. and Whiet, M., An interactive augmented
reality system for engineering education. Proc. 3rd
Global
Congress on Engng. Educ., Glasgow, Scotland, UK,
334-337 (2002).
12. VRML Models (2004), http://www.ocnus.com/models/
13. Kato, H., Billinghurst M. and Poupyrev, I., ARToolkit
User Manual, Version 2.33, Human Interface Lab. Seattle:
University of Washington (2000).
14. Woo, M., Neider, J. and Davis, T., OpenGL Programming
Guide: The Official Guide to Learning OpenGL, Version
1.2, Addison Wesley, September, (1999).
15. Kalawsky, R.S. and Hill, K., Experimental Research into
Human Cognitive Processing in an Augmented Reality
Environment for Embedded Training Systems. London:
Springer-Verlag (2000).
16. Kato, H., Billinghurst, M., Poupyrev, I., Imamoto, K. and
Tachibana, K., Virtual object manipulation on a table-top
AR environment. Proc. Inter. Symp. on Augmented Reality
2000, Munich, Germany, 111-119 (2000).
17. SpaceMouse XT Plus (2004),
http://www.logicad3d.com/press/archive/2000/20001002.html