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Lance Long/EVL

Computer scientist Andrew Johnson flies above Mars using software originally created by EVL graduate Robert Kooima with data from the NASA Mars Global Surveyor and Viking missions. Kooima’s Electro software is used to display the 3D model in CAVE2™.

Move over NASA: Explore the surface of Mars with virtual reality

by Meghan Leach
Oct 30, 2012


Lance Long/EVL

EVL director Jason Leigh and research assistant and computer science PhD student Alessandro Febretti created a 3D skeleton with organs to show how data can be shown on CAVE2™. Another EVL student lies on a bench in front of the walls for added effect. EVL OmegaLib software is used to display the 3D model in CAVE2™.


Meghan Leach/MEDILL

EVL's CAVE2 allows scientists to show massive amounts of virtual reality data all in the same area.

Hop on the Magic School Bus to Egypt or Mars!  But, in this case, hop into the magic CAVE2™ System, the Electronic Visualization Laboratory’s new virtual reality cocoon. Stand on the surface of Mars, explore ancient Egyptian ruins or squeeze inside a molecule all in a matter of minutes.

CAVE2 uses the same 3D technology as 3D movies to put people in various settings – but the settings move with their gaze and gait.

“So in this case there are 36 computers behind driving the 72 displays,” said Andrew Johnson, one creator of CAVE2 and a computer scientist with the University of Illinois at Chicago. 

While the creators recognize the application of CAVE2 to life-size video games, they really see it as a scientific tool.

“Today so much of science is interdisciplinary and collaborative; we think this is the kind of tool that is going to be necessary for people to get a handle on all this data,” said Johnson. “It gives them a unique way to look at their data and interact with their data and be inside their data.”

The virtual scene covers the 72 displays arranged in an almost complete circle around the people inside the CAVE2.

“So, as you move throughout [the circle of displays] the computer will regenerate the scene 60 times a second to give you a smooth sense of motion through that space and the objects appear to maintain their position as you walk around them or through them,” Johnson said.

One area where CAVE2 could help is the medical field.

“You have people from different specialties that have to deal with the same patient and all of them have different ways of looking at the data, and all of them have slightly different needs,” said Johnson.  “If you can give them that kind of big canvas, in this case it’s a canvas that can be 2D or 3D with lots of resolution, you’re not sacrificing anything to do that—you’re just getting a place you can all throw up your information and make sure you all agree on stuff.”

But CAVE2 also has applications in archeology with its high resolution images of ancient ruins and astronomy with its surface map of Mars.

“I think a large part of pushing the frontiers of science and engineering is about finding the right way to look at things,” said David Hofman, a physicist at the University of Illinois at Chicago, which houses CAVE2 and the laboratory that created it. “CAVE2’s cutting edge 3D and fully immersive visualization will mean that instead of having to go to the moon, researchers will be able visit the Electronic Visualization Laboratory at UIC" for their ongoing research programs.

CAVE2 takes a quantum leap beyond the technology of the first CAVE, a pioneering experiment in computer visualization that was invented in the 1990S.

“The first cave was in 1992,” said Johnson. “This one has almost 20 times the resolution of that.   It’s also phenomenally brighter and with better contrast. So things really pop—things really do seem much more realistic rather than being a sort of dimmer image that we had to live with given the technology we had 20 years ago.”

“There are couple of things about CAVE2 that make it the best immersive environment—just the incredible resolution and the brightness of the displays.  The panorama of Egypt is so bright you feel like you’re outside in the day time,” said astronomer Mark SubbaRao of the Adler Planetarium.

So how does it all work?

In stereo, each eye receives a different image. The LCD monitors display each image line by line.  Each eye alternates lines, so the left eye gets the top line, the 3rd line, the 5th line, and so on while the right eye gets the 2nd line, 4th line, etc., Johnson said.  “And there’s a barrier strip, a polarized strip in front of the screen, that basically in effect rotates the images for one eye or for another eye, and you wear similar glasses, and it basically decodes the image, so your left eye only sees the odd lines of the image, your right eye only sees the even lines of the image, and then your brain puts it together into 3D.”

The eye and the brain put it all together instantaneously – no training required.

In many ways, CAVE2 is changing the virtual reality experience.


CAVE2 has two modes: the traditional and panoptic, Johnson said. In the traditional mode, the person tracked by the virtual reality display determines the view and the 3D. For the panoptic mode, everyone wearing the glasses can see good 3D no matter where the tracked person stands in CAVE2, but the tracked person still determines the perspective.

While discussing his experience with the panoptic mode, SubbaRao said, “If you’re the tracked person, if you duck down under a railing or you sit down, it moves with you, but how 3D things are doesn’t depend on the viewer. So that means the 3D is right for everybody. It provides the first-hand experience you get in a virtual reality environment, but you can have a group experience without making it uncomfortable.”

Hofman also sees applications for CAVE2 in education.

“One of the challenges is to help students be able to visualize how a seemingly dry equation, such as Newton's famous second law F=ma [Force = mass x acceleration], is actually alive and evident all around us at all times,” Hofman said.  “The CAVE2 shows how we can do this. It is at the forefront of education and I, for one, am only just starting to grasp its true potential in explaining difficult subjects and making science come alive.”

Johnson got hooked on virtual reality programming because of the first CAVE, so he has high hopes for CAVE2.

“I’m hoping that it inspires the current generation as much as I was inspired back then,” Johnson said.