Is 'glasses-free' 3D coming soon to a theater near you?

Moviegoers, rejoice! A team of researchers has brought glasses-free 3D cinema closer to reality.

Researchers from MIT's Computer Science and Artificial Intelligence Lab (CSAIL) and Israel's Weizmann Institute of Science has demonstrated a display that lets you watch 3-D films in a movie theater without extra eyewear.

Dubbed 'Cinema 3D,' the prototype uses a special array of lenses and mirrors to enable viewers to watch a 3-D movie from any seat in a theater.

"Existing approaches to glasses-free 3-D require screens whose resolution requirements are so enormous that they are completely impractical," said co-author Wojciech Matusik. "This is the first technical approach that allows for glasses-free 3D on a large scale."

While the researchers cautioned that the system isn't currently market-ready, they are optimistic that future versions could push the technology to a place where theaters would be able to offer glasses-free alternatives for 3-D movies.

Glasses-free 3-D already exists, but not in a way that scales to movie theaters. Traditional methods for TV sets use a series of slits in front of the screen (a "parallax barrier") that allow each eye to see a different set of pixels, creating a simulated sense of depth.

"With a 3-D TV, you have to account for people moving around to watch from different angles, which means that you have to divide up a limited number of pixels to be projected so that the viewer sees the image from wherever they are," said Gordon Wetzstein. "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."

The team demonstrated that their approach allows viewers from different parts of an auditorium to see images of consistently high resolution.

Cinema 3D isn't particularly practical at the moment: the team's prototype requires 50 sets of mirrors and lenses, and yet is just barely larger than a pad of paper. Matusik says that the team hopes to build a larger version of the display and to further refine the optics to continue to improve the image resolution.

"It remains to be seen whether the approach is financially feasible enough to scale up to a full-blown theater," said Matusik. "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."

The study has been presented at the meeting SIGGRAPH 2016.