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Marcella McCarthy/MEDILL

With an iPad as his palette and an 18 screen wall as his canvas, JD Pirtle uses his artistic skills in a futuristic way.

Researchers paint on 20-foot electronic canvas

by Marcella McCarthy
Nov 04, 2010


Marcella McCarthy/MEDILL

Students at EVL turned the iPad into a painters' palette

evl wall2

Marcella McCarthy/MEDILL

18 HD touch-enabled wall at the Electronic Visualization Lab

Philip Pilosi

Marcella McCarthy/MEDILL

Philip Pilosi sits back and watches his work in action


Marcella McCarthy/MEDILL

Arthur Nishimoto starts up the "20-Foot Canvas"

JD Pirtle, 35, held a paintbrush up to his chin, and like a
traditional painter, contemplated what he was going to paint that day.
But he wasn’t using any paint and he wasn’t even using a canvas.
Instead, he just walked up to a wall comprised of HD screens. With a
flick of the wrist and a light stroke, he began painting a sunflower
on the virtual wall.

“I like to call it 20-foot canvas,” said Pirtle, who is earning his
masters degree in fine arts at the University of Illinois at Chicago
and is the lead artist on the paint project.

At UIC's Electronic Visualization Lab, students have built a wall out of 18 HD screens with an astounding
number of pixels: 8160 x 2304. A comparable single screen comprises
1920 x 1080 pixels. But wait, it gets better. This summer, a group of
five students made the wall touch-enabled and created an application
for the iPad that allows more than one person to paint on the virtual

EVL nurtures the partnership between artists and computer scientists
specializing in advanced visualization and networking technologies.
Think back "a long time ago [1977]  in a galaxy far, far away" - EVL
worked on the computer animation used in the creation of Star Wars.

“One of the reasons I came to this university is because it has a
collaboration between engineers and artists,” said Pirtle.

Arthur Nishimoto, 23, is a graduate computer science student at EVL.
Having worked a great deal with TacTile, a touch-enabled table
composed of one HD screen, Nishimoto served as an advisor on making
the wall touch sensitive.

EVL is known for developing new technologies using already available
products. And the touch-enabled wall is no different. “We took our own
ideas and adapted them to commercial devices,” Nishimoto said.

The team used touch overlay technology – a frame that one places
around the outside of an LCD or plasma display which then makes the
screen touch sensitive. When the team got the touch frames, it was
Nishimoto’s responsibility to evaluate the technology.

“One challenge was getting the hardware to work,” Nishimoto said.
While TacTile operates based on optical technology – cameras track the
touches – the wall works a bit differently he said. The wall uses
infrared light that is emitted and detected to recognize touches. When
a finger – or any other object – interferes with the infrared light
rays, the wall acknowledges a touch.

While Nishimoto has even developed videogames that can be played on
the wall, most recently he, Pirtle and undergraduate computer science
student Philip Pilosi, 22, have been working on “20-foot canvas,” an
unofficial name for the unnamed paint project.

Pirtle designed an application for the iPad that turns it into a
painter’s palette. The wall picks up 32 touches simultaneously, which
allows for the creation of a mural. But at the moment, the single
holder of the iPad controls the color that is painted on the wall.

“Our dream would be to have each person [stand] up their with their
own iPad,” Pirtle said.

The painter’s palette that Pirtle designed allows the user to choose
between 16 different colors and even mix them to come up with custom
colors just as a traditional painter would. Also, one can choose their
tool of choice, a pencil or a paintbrush, depending on the artistic
requirements of the masterpiece to-be.

But how does the information on the iPad reach the wall? That’s where
Pilosi came in. The iPad and the wall are connected over a wireless
network he said. “It takes the color and breaks it into a string of
characters and sends it over the wireless network to the wall.”

The touch overlays were supplied by PQ Labs, a Silicon Valley-based
company that provides multi-touch solutions. But very few people are
familiar with multi-touch on such a large scale. Wei Liu, vice
president of business development for PQ Labs said that the way EVL
has assembled the screens is unlike anything he’s seen. “It’s a
revolutionary solution for the large size,” he said. “I think it’s a
great project.”