Perceptually Modulated Level of Detail for Virtual Environments
dc.contributor.author
Reddy, Martin
en
dc.date.accessioned
2004-06-15T08:55:07Z
dc.date.available
2004-06-15T08:55:07Z
dc.date.issued
1997-07
dc.description
Institute for Computing Systems Architecture
en
dc.description.abstract
This thesis presents a generic and principled solution for optimising
the visual complexity of any arbitrary computer-generated virtual
environment (VE). This is performed with the ultimate goal of reducing
the inherent latencies of current virtual reality (VR)
technology. Effectively, we wish to remove extraneous detail from an
environment which the user cannot perceive, and thus modulate the
graphical complexity of a VE with little or no perceptual artifacts.
The work proceeds by investigating contemporary models and theories of
visual perception and then applying these to the field of real-time
computer graphics. Subsequently, a technique is devised to assess the
perceptual content of a computer-generated image in terms of spatial
frequency (c/deg), and a model of contrast sensitivity is formulated
to describe a user's ability to perceive detail under various
conditions in terms of this metric. This allows us to base the level
of detail (LOD) of each object in a VE on a measure of the degree of
spatial detail which the user can perceive at any instant (taking into
consideration the size of an object, its angular velocity, and the
degree to which it exists in the peripheral field). Additionally, a
generic polygon simplification framework is presented to complement
the use of perceptually modulated LOD.
The efficient implementation of this perceptual model is discussed and
a prototype system is evaluated through a suite of experiments. These
include a number of low-level psychophysical studies (to evaluate the
accuracy of the model), a task performance study (to evaluate the
effects of the model on the user), and an analysis of system
performance gain (to evaluate the effects of the model on the
system). The results show that for the test application chosen, the
frame rate of the simulation was manifestly improved (by four to
five-fold) with no perceivable drop in image fidelity. As a result,
users were able to perform the given wayfinding task more proficiently
and rapidly.
Finally, conclusions are drawn on the application and utility of
perceptually-based optimisations; both in reference to this work, and
in the wider context.
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dc.format.extent
1297764 bytes
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dc.format.extent
4239775 bytes
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dc.format.mimetype
application/pdf
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dc.format.mimetype
application/postscript
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dc.identifier.uri
http://hdl.handle.net/1842/505
dc.language.iso
en
dc.publisher
University of Edinburgh. College of Science and Engineering. School of Informatics.
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dc.subject.other
virtual environment
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dc.title
Perceptually Modulated Level of Detail for Virtual Environments
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dc.type
Thesis or Dissertation
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dc.type.qualificationlevel
Doctoral
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dc.type.qualificationname
PhD Doctor of Philosophy
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