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Deep Vision Display Wall is larger-than-life and 3-D
By Brian Fitzgerald
Put on the 3-D glasses -- yes, the kind worn during a 3-D movie at the theater -- and you can look inside a giant rib cage to see how a pacemaker interacts with a patient’s tissues. Webs of yellow, red, and blue lines extend from a green rectangle that represents the defibrillator, showing how electrical currents travel through the chest.
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| The Deep Vision Display Wall shows oversized and extremely detailed 3-D images. Photo by Kalman Zabarsky | |
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The computer model on the 15-foot-by-8-foot screen is one of several
demonstrations from BU’s Scientific Computing and Visualization
Group as it unveils its recent creation: the Deep Vision Display Wall.
The first of its kind in the nation, the wall is driven by a Linux cluster
of dual-processor IBM X330 servers, which renders and manipulates the
larger-than-life computer models to better study processes such as space
weather, molecular dynamics, and earthquakes.
“It’s a mechanism that can be used for exciting discoveries,”
says Glenn Bresnahan, an adjunct assistant professor and the group’s
director. “You can go into areas where you normally couldn’t
go -- to visualize objects that are impossible to experience in real life.”
For example, the pacemaker research, conducted by biomedical engineering
graduate student Daniel Mocanu (ENG’03), shows the potential for
using patient-specific computer models in determining the best location
in a patient’s chest to put a defibrillator. This varies from person
to person because of the inhomogeneous nature of the human thorax, so
computational methods of examining defibrillation based on CT-scanned
images “may also prove effective in finding the optimum placement
for the electrodes,” says Mocanu. “You can also see the electric
field inside the heart. Therefore, if you don’t like the position
or the size of the electrodes, you can make changes to them.” He
adds that the 3-D model is useful in determining the strength of defibrillator
shocks needed. “An electric current that is too strong can injure
the heart,” he says, “and one that is too weak won’t
be effective.”
The wall can be used for a wide variety of research, from studying a DNA
molecule to observing a comet’s tail. It could also help companies
such as automakers design better products more quickly. Theoretically,
a car manufacturer could interchange models of engine components on a
vehicle and see the overall design impact immediately. “Anyone who
is doing a design of a three-dimensional structure could certainly use
this technology,” says Bresnahan.
He explains that although scientists have long used computers to run experiments
with 3-D images, “until recently it hadn’t made technical
or financial sense to use such large and high-resolution images. The powerful
commodity PCs, coupled with the Linux operating system, however, permits
this technology to be installed at a relatively affordable price.”
For years, researchers at BU have used two ImmersaDesks, which provide
large, semi-immersive, table-format virtual displays on four-foot-by-five-foot
screens. The Deep Vision Display Wall, however, gives scientists the opportunity
to visualize their data in more detail than ever before possible. The
first public showing of the wall, when it was 10 feet wide and 7.5 feet
high, was at a supercomputing conference in Denver in November 2001. It
was also demonstrated at a supercomputing conference in Baltimore last
month. The wall was recently expanded to its current size, and the group
will eventually increase the number of liquid-crystal display projectors
from 12 to 24. “This will produce a much higher image resolution,”
says Display Wall team member Laura Giannitrapani, graphics manager at
the Office of Information Technology.
One of the group’s favorite demonstrations is “virtually”
immersing a person wearing the 3-D glasses -- with polarizing lens, just
like the movies -- in the middle of a school of computer-generated sharks,
underwater bubble sounds and all. It’s not exactly as chilling as
scuba diving in the middle of a feeding frenzy, but the effect is uncanny,
as many a viewer reaches out to touch the fish. In another demonstration,
developed by Claudio Rebbi, a CAS physics professor and director of the
Center for Computational Science, the wall presents British scientist
Thomas Young’s 1801 “double-slit” experiment showing
the wave nature of light, which disproved Isaac Newton’s theory
that light was made up of tiny bullet-like particles. “It’s
a classic quantum physics experiment,” says Bresnahan, “that
shows that light behaves both like waves and particles.”
The wall may even have a future in the computer game market, where virtual
reality would take on a new meaning with such large-scale images. Bresnahan
envisions the possibility of the wall being used for presentations to
large groups of people. “I can easily imagine the Deep Vision Display
Wall in conference rooms,” he says. “At the extreme, you could
also have four large walls on video projections screens and be completely
surrounded by the imagery. The possibilities are endless.”
13 December 2002
Boston University
Office of University Relations