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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004
Figure 10. The GISMO client uses SpeedTreeRT to visualise
realistic looking trees in real-time.
6. CONCLUSION
The article gave an introduction to 3D game engines and how
these software packages can be used to develop serious
visualisation applications. A problem is still, however, to get
existing spatial data into a format that the game or the
accompanying editors and tools understand. Once this
obstacle has been overcome, the powerful rendering modules
create beautiful indoor and outdoor scenes in real-time. If
desired, the other modules of the game engine enable
physically correct walkthroughs or fly-over even in a multi-
user world. Such applications are far more desirable then pre-
generated movies that are still commonly used for
presentation purposes and the demand for real-time systems
steadily increases. Especially in application areas like urban
planning, emergency response, tourism and traffic
management, the freedom of movement that game engines
offer are of great interest.
Game engines aim for PC environments, so that the
visualisation of photo-realistic, textured landscapes is now
available for almost everyone. With the introduction of
mobile 3D graphics chipsets that will soon make their way
into cell phones, handheld video consoles and portable
multimedia stations, 3D games and visualisation will be at
everyone's hand at all times. There are many game engines
available as source code or as binary runtime library that are
free for non-commercial applications. Other sources for
powerful visualisation software are the many game-like
libraries available in the internet. Two such libraries, namely
OpenSceneGraph and libMini have been successfully used in
the real-time visualisation of large-scale urban landscapes.
The project GISMO has demonstrated that these libraries are
capable of rendering huge data sets at interactive frame rates
and are thus a good alternative to commercial products. They
are also very easy to use and can be easily integrated into
other software products.
A big improvement to the réalism of virtual environments is
the inclusion of vegetation. Tree libraries are now available
that are successfully used in commercial game products.
Other libraries will soon follow that will be able to render all
kinds of vegetation like grass and bushes.
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