Distributing 3D information over the internet using VRML
A screen shot of the above VRML file is shown in Figure 1. The VRML file is displayed using
Internet Explorer using a Microsoft VRML viewer.
Figure 1. Screen shot of a simple VRML file using Internet Explorer
For specifying surfaces, the ElevationGrid maybe used. The ElevationGrid may be used to
display terrain generated from digital terrain models (DEMs). An example of an ElevationGrid
is shown in Figure 2.
Figure 2. An example of a VRML ElevationGrid node displayed in a VRML viewer.
For additional information on VRML developments, specifications, viewers, and working groups
see the web site http: //www.vrml.org. Another popular site for finding information on the
VRML technology and whereto find VRML files on the Internet is the VRML Repository web
site http:lhnvw.sdsc. edu/vrml.
Applications of VRML
VRML maybe used for educational, entertainment, and scientific purposes. Some examples of
how VRML files are being used today include simulators, games, 3D visualizations, design, and
3D user interfaces. Examples of how VRML maybe used by utilities include line-of-site
analyses, visualizations of 3D structures, and sewer pipe design using digital terrain models.
One of the official VRML Working Groups is examining ways to use VRML for displaying georeferenced
data. This Working Group, called the GeoVRML Working Group, was formed to
determine if modifications to the VRML specification will be necessary. The GeoVRML
Working Group is currently focusing on several key areas such as coordinate systems, time
referencing, terrain representation, levels of detail, resolution and accuracy, and data interchange.
Additional information on the GeoVRML Working Group maybe found at the VRML
Consortium web site (http://www.vrml.org).
Conclusion
VRML provides a means for communicating 3D scenes and information over the Internet.
VRML scenes can be created using a simple text editor or authoring or data translation tools.
These scenes, which are called worlds, may be viewed in common Web browsers with
compatible VRML viewers. Although the VRML standard is fairly new, many examples of how
it can be used have been developed for educational, entertainment, user interface, and
visualization purposes. One area of active research is how to apply VRML for representing georeferenced
data in accurate and practical ways. Several challenges are being examined including
how to specifi coordinate systems, resolution and accuracy of coordinates, and data interchange
methods. As these issues are addressed and worked into the VRML standard, VRML could
become a very popular and effective means for sharing 3D information over the Internet.
References
- Abernathy, M. and Shaw, S., 1998, Integrating Geographic Information in VRML Models,
VRML'98 Conference, Monteray, California.
- Ames, A. L., Nadeau, D. R., and Moreland, J.L., 1997, VRML 2.0 Sourcebook, Second Edition,
John Wiley & Sons, Inc.
- Bell, G. and Carey, R., 1997, The Annotated VRML 2.0 Reference Manual, Addison Wesley
Developers Press.
