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Geological virtual reality
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Chris Harding builds interactive geoscientific virtual environments
that use 3D vision, touch and sound.
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Chris Harding wants to not only observe but also touch and hear data
in virtual environments.
His National Science Foundation funded project is researching natural
and intuitive ways for geoscientists "to perceive and interact with
surface data via vision, touch and sound."
Through an Omni phantom haptic (force-feedback) device, Harding, an assistant
professor of geological and atmospheric sciences, says one can touch virtual
objects through a stylus attached to this robot's arm.
"You can use this device to ‘feel' the shape of a geological surface
with a ‘virtual fingertip' and to change this shape by deforming it via
a virtual tool," Harding says.
Harding combines geoscience research and teaching with the emerging field
of virtual reality – especially the combination of vision, touch and sound,
so-called "multi-modal" interaction. In addition to his appointment
in the Department of Geological and Atmospheric Sciences, he is a member
of the Human Computer Interaction (HCI) program and the Virtual Reality
Applications Center, which is housed in Howe Hall.
As a teenager, Harding was interested in technology and was fascinated
with computer programming.
But geoscience was also an interest of his.
"I wanted to see if I could combine my interests but never thought
this would be possible in a university setting," he said. "I
can't be classified as a traditional geologist but I'm not a true computer
scientist either. I'm not a specialist in any one area and never expected
to get an opportunity for an academic career."
He was involved in virtual reality work at both Shell and Exxon, where
he worked with large stereo displays (virtual theaters), scientific sonification
and haptic interaction with geophysical data.
Then he became aware of the HCI program at Iowa State and was among that
initiative's initial hires.
He says that the combination between the geosciences and virtual reality
is a natural extension of the way geoscientists work with 3D data.
"Geoscientific tasks carry a special set of problems and need certain
approaches. Many geologists already use computer programs to explore and
visualize 3D geoscience data, sometimes even in a VR system, but when
they want to express a new spatial idea they instinctively grab a pen
and start drawing," he said.
"I'm trying to show geoscientists a new way to directly and manually
interact with their data, similar to sketching and correcting shapes on
paper - but in true 3D. From my geoscience background I can speculate
what types of typical interactions and tasks we can propose to improve
on by using a haptic VR system. Once the system is built, we will have
the practitioners test it and evaluate its usefulness."
Using the Omni Phantom device to touch a virtual surface, various types
of force effects are generated, such as hardness or friction. His interactions
are deliberately based on everyday tool-object interactions such as deforming
clay or drawing or cutting paper because the user will already have that
skill.
His "piece of paper" is actually a huge digital elevation model
or a fault plane. Harding says few people have had to think about how
deforming this rather abstract 3D should feel. The specifics of a multi-sensory
interaction technique are more guided by what works effectively for humans
in virtual reality.
"This can be different from how reality works," he says. "I
think one needs to acknowledge that a weird form of creativity comes into
play when developing these new human-computer interaction schemes."
In addition, Harding says, "audio signals" can be used to present
additional data about the current point of contact. When a user touches
a 3D terrain model, its elevation (height) values can be "sonified"
by playing musical notes with a certain pitch, if a low elevation is touched
a low-pitched note is played.
As the user moves the "virtual fingertip" to higher elevations,
an increasingly higher pitched note is played. Or, instead of sonifying
the terrain's height, which the user can also see, the terrain's slope
steepness at the contact point could be sonified so that the sound truly
compliments the visual input and the haptic feedback.
Harding says this no-cost add-on information could be very helpful when
user actually deforms the terrain in real-time and needs to get continuous
updates about the current slope.
"For most scientist, this still sounds like science fiction type
stuff," he says. "VR and especially the combination of 3D vision,
haptic interaction and audio responses are still frontier disciplines.
As more and more of the necessary pieces of software and hardware technology
come together, the challenge for me is to combine these pieces into a
system that could eventually be used effectively for everyday work with
geoscience data in academia and industry."
Harding's research requires work across academic disciplines, which he
says requires not only many different kinds of computer technology, but
also human-factors, user interface design and cognitive psychology.
"Obviously, in a lot of cases I'm not the expert so there's a lot
to learn and trying to create such a novel system is always a gamble,"
he said. "We spend a lot of time investigation new methods, following
interesting ideas and jumping across established boundaries."
One of those boundaries Harding and his students are just starting to
think about is how to use a touch/sound virtual reality system to help
visually impaired students understand abstract mathematical data by allowing
them to feel a shape equivalent to a 3D graphic of the data.
"Similarly, it would be interesting to add touch or sound to information
systems like Google Earth to make them more accessible and more effective,"
Harding said. "Multi-disciplinary connections are at the core of
developing emerging technologies."
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Chris Harding
Around LAS
April 23 to May 6, 2007
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