On a recent Friday afternoon, a group of Brown geologists donned special glasses and stepped out onto the surface of Mars. No spacesuits or rockets were required for this journey, however. It was all done right on College Hill, in Brown’s 3-D virtual reality room known as the YURT.
About 10 students and professors assembled in the circular room with a cone-shaped ceiling (hence the name YURT, which stands for Yurt Ultimate Reality Theater). The group was instantly enveloped—on all sides, underfoot and overhead—by the stark and rusty Martian landscape. A few of the students extended their arms momentarily to catch their balance as they scanned their alien surroundings, projected in dazzling high-definition 3-D.
To Mars and Back in a Few Minutes
Stereoscopic images on the ceiling and floor enhance the feeling of total immersion that earlier virtual reality efforts aspired to achieve. The YURT lends itself to projects from scientific exploration to the visual arts. “Ooh, look at this,” said geology professor Jim Head, pointing to a spot off in the Martian distance. “Mike, take us over there.” Mike Bramble, a graduate student in the planetary sciences group, toggled a few buttons on a controller that looks a bit like a space-aged magic wand. In an instant, the group was whisked across the stony red surface, arriving at the base of a squat mesa where two geological units meet. Everybody leaned in to get a closer look.
That closer look is just what computer science professor David Laidlaw had in mind when he started designing the YURT six years ago. “What we set out to do,” Laidlaw said, “was to build the ultimate virtual-reality display.” The YURT opened for business late last semester, but a team of technicians has been working throughout this semester to put the finishing touches on the unit. Already, researchers from geology, evolutionary biology, medical sciences, and computer science, as well as artists and writers, are putting the YURT through its paces. “This is really amazing, especially for people in our field,” Head said. “It’s not easy to get to the other planets, but we’d really like to have that sense of ‘being there.’ To be able to go into the YURT and wander around through these landscapes is just incredible.”
Emerging from the Cave
This is by no means Brown’s first foray into virtual reality. Nearly two decades ago, computer scientist Andy van Dam built the Cave, the YURT’s forebear, which still operates in the Granoff Center. The Cave proved to be a valuable educational and research resource. It has been host to semester-long classes in which students created scientific visualizations of bats in flight. An application called ARCHAVE gave archaeologists a tool to explore ancient ruins virtually. And a program called Cave Painting enabled visual artists to paint images in three-dimensional space.
“One of the things we discovered was that while the Cave was great and we could do cool stuff, there were limitations,” Laidlaw said. “Those limitations were fundamental. They prevented researchers and designers from doing what they wanted to do.”
A Well-rounded Experience
The YURT’s rounded geometry solved projection problems of an earlier generation square-cornered VR facility, and 69 stereo projectors serving up 2 million pixels each offer resolution matching the capabilities of the human eye. One limitation had to do with the square Cave’s geometry. The corners interfered with a user’s sense of immersion, as did the lack of image projection on the ceiling and the limited projection on the floor. The image quality wasn’t quite up to snuff either. The resolution was low compared to what the human eye can see. The limited image contrast washed out the colors on parts of the display, and the low brightness made colors difficult to distinguish.
With an eye toward improving those capabilities, Laidlaw applied for and won a $2-million grant from the National Science Foundation to build the YURT. The YURT’s rounded geometry took corners out of the picture. The unit’s 69 stereo HD projectors beam 2 million pixels each onto a 360-degree display. Images also cover the entire floor and most of the conical ceiling. At standard viewing distances, the resolution matches what is discernible by the human eye.
“If we can get our display to the resolution of our eyes, we’re done,” Laidlaw said. “We don’t need to go further, and that’s what we did.” Not that it was easy. “We had to wait for industry to catch up for the projectors,” Laidlaw said. “We delayed the project almost a year and a half because we couldn’t find a projector that would do full resolution in stereo. We ended up having to buy custom projectors.” Installing the unit’s clear acrylic floor was a challenge as well. It was delivered in one pentagonal chunk, 16 by 12 feet in size. Installing it required the removal of the exterior of the Yurt’s home at 180 George Street as well as one interior wall.
A Research and Teaching Tool
All that work is already starting to pay dividends as faculty and students from across campus have started making use of the YURT. Bramble, the planetary geology graduate student, said he’s been able to see features on Mars in a way that simply hadn’t been possible before. He’s been researching a region called Northeast Syrtis, a spot high on NASA’s list of potential landing sites for its next Mars rover. Bramble often uses 3-D images taken by NASA’s orbital HiRise instrument, but he usually has to view them on a desktop computer screen. Seeing them in the Yurt was a whole different ballgame, and it’s led to new insights.
“There were light-toned surfaces and dark-toned surfaces, but at my monitor it didn’t appear that they were significantly different units,” Bramble said. “Looking at this scene in the YURT showed that the light-toned unit was a particular height and then dropped down rather abruptly a handful of meters to the second flat plain, which was darker in tone. As a result, our manuscript in the works has been updated to reflect this observation.” In the future, Head says the YURT could be useful in training the astronauts who will be exploring these surfaces in real life. “We had the 20th NASA astronaut class up from Houston and in the Cave a few years ago, exploring Mars, and we literally couldn’t get them to leave,” Head said. “We plan to do the same in the YURT.”
Stephen Gatesy, an anatomist and evolutionary biologist, is working as a scientific collaborator for a class called Virtual Reality Design for Science, taught by Laidlaw and RISD professor Fritz Drury. Gatesy has been studying fossilized footprints made by ancient dinosaurs, and he’s working with students in the class to develop 3-D animations of how those tracks may have been made. “A lot of what I’m doing is trying to understand very complicated 3-D patterns that change through time,” he said. “I think it’s only natural to take something that’s inherently three dimensional – the motion of an animal, or in this case the motion of mud produced by an animal – and visualize it in 3-D, where our eyes are good at understanding things.”
John Cayley, professor of literary arts, has taught a class in the Cave for the last few years. He’ll continue to use the “legacy Cave,” as it has been dubbed, but he’s looking forward to getting his class into the YURT next semester. Students in the class create texts in three dimensions, enabling readers to travel through words and phrases as they read them, positioned in artificial space. “What I try to get the students to do is think about the Cave or the YURT as housing new machines for writing and reading,” Cayley said. “I assume we’re going to be reading and writing forever, and, in the future, we’re going to continue to do so in these virtual and augmented spaces. How are we going to do that? That’s what I encourage the students to explore.”
The Nature of Virtual Reality
Laidlaw hopes that as word spreads about the YURT, other researchers and teachers around campus and beyond will want to make use of it. “I want this to be a test bed for virtual reality,” he said. “I want to quantify the value of VR and explore the areas in which different aspects of VR pay off.” He also wants to understand the ineffable effect virtual reality seems to have on its users. “Going in the YURT, there’s some kind of magic thing that happens,” Laidlaw said. “But honestly I don’t know what the magic is yet. So part of why I wanted to build the YURT was to understand that, to see if there’s a way to better describe or explain what that magic is.”
