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Difficulties with VRML
Unlike HTML, the language with which it is most frequently compared,VRML is not
easy to learn, and its syntax is certainly not so flexible or intuitive. Even with prior
experience in other programming languages or environments, a significant amount of
dedicated study and practice would be necessary for an organisation's staff to be able to
construct its own realistic virtual worlds. As outlined previously, visual development
environments are easier to use, but often produce less efficient code and can be
expensive.
Bandwidth restrictions are the factor most likely to hamper the deployment of VRML
across the Web. Broadband access remains rare in the home, and in order for VRML
worlds to be as realistic and explorable as possible, the source files must necessarily be
large. On slower computers, rendering time may be a problem, particularly in ensuring
that users do not reach parts of the world that the processor has not had time to render.
This problem is compounded when images are photomapped onto the surfaces.
Conversely, reduction of file sizes and polygon count can cause distortion and a loss of
believability, thus detracting from the initial aims of virtual reality.
Extensible 3D (X3D)
Little tangible progression seems to have been made with VRML since 1997, apart
from the slow genesis of X3D, which is the Web 3D Consortium's next-generation,
backwardly-compatible successor to VRML. Its mission is `to bring rich and compelling
3D graphics to the Web.'
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The format is intended not only for storing and displaying 3D graphics but also as a
middle ground between different graphics programs, allowing them to exchange files
between them. Essentially, X3D will hold the same benefits for VRML users as XML has
for HTML professionals, ensuring that files are properly structured and easily transferable.
Like VRML, X3D has its own dedicated development environments.The Web 3D
Consortium
has developed its own X3D-Edit Authoring Tool
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, and Xj3D Java
Implementation is also currently in development.
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QuickTime Virtual Reality (QTVR)
QTVR is not a virtual reality technique, nor does it render images in three dimen-
sions. It is, however, significant in any serious discussion of contemporary VR, particularly
given the quandaries surrounding contextualisation and where to draw the line. In
Melissa Terras's
VRML model of Sen-nedjem
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, the tomb is not actually in isolation, but
it proved to be too computationally intensive to render even static models of the other
tombs. A reasonable solution was to surround the VR model with a static photorealistic
Virtual Reality and
Display Technologies
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From http://www.web3d.org/x3d.html
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See http://www.web3d.org/TaskGroups/x3d/translation/X3D-EditAuthoringTool_files/frame.html
for details.
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See http://www.web3d.org/TaskGroups/source/xj3d.html
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Internet Archaeology, http://intarch.ac.uk/journal/issue7. Melissa Terras completed this project at
HATII (University of Glasgow) in conjunction with the Kelvingrove Museum and Art Gallery.