How MIT researchers created a 3D movie screen, no glasses required

For years, the idea of watching movies and TV in 3D seemed intriguing, but came with limitations. For many early adopters, the required 3D glasses became cumbersome, others complained of motion sickness.

Now a team of researchers at the Massachusetts Institute of Technology (MIT) and Israel’s Weizmann Institute of Science say they have developed a prototype of a new 3D movie screen that would allow viewers to jettison the glasses, able to enjoy the same viewing experience from any seat in the theater.

But their prototype screen, known as Cinema 3D, comes as some of the enthusiasm that once surrounded 3D has shifted to the promise of virtual reality technology. Partly, the spotlight change is because of concerns about creating 3D content, while some say virtual reality could also a greater potential beyond the world of entertainment, in areas ranging from aiding astronauts to transforming courtrooms.

Still, the researchers say, for creating a life-like 3D movie experience, the new system represents a step forward for a technology that’s fascinated viewers since Life Magazine published a famous picture of a glasses-wearing audience at a 3D movie in 1952.

“Existing approaches to glasses-free 3-D require screens whose resolution requirements are so enormous that they are completely impractical,” said professor Wojciech Matusik of MIT's Computer Science and Artificial Intelligence Lab (CSAIL), who co-authored a paper on the new technology, in a statement. “This is the first technical approach that allows for glasses-free 3-D on a large scale.”

The Cinema 3D system uses a series of 50 lenses and mirrors to create a number of slits known as “parallax barriers,” which shows a slightly different set of pixels to each of the viewer’s eyes, creating a sense of depth to the image.

But using the idea that people in movie theaters tend to move their heads relatively little, as they are constrained by their seats, the system displays the 3D images to a narrow range of angles and then replicates that to every seat in the theater.

That’s an improvement over many existing 3D TV systems, which also use parallax barriers, but require a set distance between the viewer and the screen, making the technology impractical for large theaters with seats at a variety of angles and heights.

“The authors [of Cinema 3D] cleverly exploited the fact that theaters have a unique set-up in which every person sits in a more or less fixed position the whole time,” said Gordon Wetzstein, an assistant professor of electrical engineering at Stanford University, who was not involved in the research, in the statement.

However, some have predicted that while the 3D technology is improving, the more immersive potential of virtual reality could have a larger impact, especially beyond games, movies, and TV.

“The technology is still changing, and it’s going to continue to improve. But here’s the thing, virtual reality might eat 3D’s lunch before it ever gets a chance,” tech site The Verge’s David Pierce said in a 2013 video report.

“Good virtual really doesn’t just appear to add depth, it has depth. An object will look different depending on how you look at it, and you can even look at it from the back. You can’t do that with a 3D camera,” he added.

One of those uses is in jury trials. Researchers at the University of Zurich published a paper examining how juries could virtually examine a 3D reconstruction of a crime scene with a nearly 360-degree view using the Oculus Rift virtual reality headset.

Some legal experts say it could eventually come to impact how juries examine evidence.

“I think these things are inevitable,” Carrie Leonetti, a law professor at the University of Oregon told The Atlantic's CityLab last year. “I think there will eventually be a tipping point between VR being this awe-inspiring thing and it being something like a PowerPoint,” she added.

In the past, jurors have rarely made physical visits to a crime scene, partly because of concerns that they could bias jurors’ view of how events unfolded. One visit, made by jurors during the OJ Simpson trial in 1995, suggested seeing the locations in person had a powerful impact not offered by photos or video, The New York Times reported at the time.

Professor Leonetti says virtual reality could offer a similarly close look, without the need to physically transport the jury. “Imagine a trial where somebody is charged with homicide, and their defense is self defense. Each side would have a virtual environment that would look really different,” she told CityLab.

NASA has also had its own VR lab since the 1990s, which it uses as a training facility for astronauts on Extravehicular Activity spacewalks.

One goal, using software that generates realistic graphics of space to be used in training scenarios, is to allow astronauts to “pre-choreograph” spacewalk procedures on the ground, making maneuvers and repairs of the International Space Station the Hubble telescope more efficient, wrote NASA’s Anna Seils.

For entertainment, however, both 3D movies and those designed to be viewed in virtual reality are gaining ground. Many Hollywood studios have begun releasing a variety of movies in both 3D and IMAX 3D formats, though these currently require specialized glasses.

But the MIT researchers say the new Cinema 3D technology also offers an improvement over other glasses-less technology.

Such technology, they note, often uses projectors to cover the viewing angle of the entire audience. That can often cause a decline in the resolution of the image, because only a limited number of pixels is shown to each viewer.

By showing only a narrow range of angles and then replicating that effect using a series of mirrors, the researchers’ system is able to display images at a much sharper resolution, they say.

They’re now hoping to further refine their research, which is being presented at the SIGGRAPH computer graphics conference this week in Anaheim, Calif., to make it a commercially viable product.

“It remains to be seen whether the approach is financially feasible enough to scale up to a full-blown theater,” Professor Matusik of MIT said in a statement. “But we are optimistic that this is an important next step in developing glasses-free 3-D for large spaces like movie theaters and auditoriums.”