Hands-On with The CastAR Augmented Reality Glasses

By Norman Chan

The startup founded by two ex-Valve engineers showed their first prototypes at this past weekend's Maker Faire.

As any attendee of Bay Area's Maker Faire can attest, jaw-dropping projects can be found in almost every nook and cranny of the San Mateo Fairgrounds where "burning man for nerds" has mades its home for the past eight years. That was absolutely true this year: tucked away in the corner of the darkened Fiesta Hall (where the Tesla coils and EL-wire projects typically live), and far away from the main Expo pavilion, was the booth of small startup Technical Illusions. You may not have heard about this company before, but its founders' former employer was Valve Software, and its team is composed of ex-engineers from Valve's disbanded hardware initiative. Jeri Ellsworth and Rick Johnson--with the blessing of Valve--were able to take the project they were working on and continue developing it as a commercial product. That project, augmented reality glasses called castAR, made its public debut this past weekend at Maker Faire, and we were able to test them out in early demos.

We spoke to both Jeri and Rick on camera about the development and their hopes for castAR, and will have that video on the site this week. But here's a quick explanation of how it works, what the experience is like, and why it's nothing at all like the Oculus Rift.

castAR is a pair of active shutter glasses, much like the stereoscopic 3D glasses that were popular before the passive polarized glasses used for most 3D TVs today. Each lens flickers at 120Hz, but instead of showing a 3D image that's displayed on a static TV or monitor, they're made to view images projected from the very glasses themselves, bouncing back toward the lenses from a special reflective surface. Two tiny pico-projectors sit on top of each lens to display left and right images, which are aligned so that you're always seeing a 3D image as long as you're looking at the reflective table surface--there's no framing around the image as there would be around a TV. That means no matter how you move your head around, you'll always see the "screen" since the projectors are moving along with your head.

But the special sauce that makes castAR work is head tracking.

Between the two projectors sits a camera that recognizes infrared LEDs positioned at corners of the reflective surface. That camera triangulates the position of your head, so the software knows what angle you're looking at the surface from at all times. The games use that information to simulate fixed 3D objects in the space in front of you, so you can move your head around them and see objects from different sides. It's truly like Tony Stark's interactive 3D models from the first Iron Man movie.

Interactivity is important for castAR, because Jeri and Rick are at heart still game developers. The demos I tried at Maker Faire--a rudimentary Jenga-like tower and zombie shooter in a 3D maze--made use of different controller accessories to interact with the game. The tower game employed a wand with an IR LED that was also tracked by the glasses, which I used to knock down the tower of blocks. But you could easily imagine the wand being replaced by other trackable controllers like D&D figurines or even gloves. The zombie shooter was controlled with a standard Xbox gamepad, but we were encouraged to move our head around the maze environment to look around corners and over walls, where a second player wouldn't be able to see. I kept wanting to reach my hand out and touch the 3D walls--the head tracking was that good. And even though we had only about 10 minutes play time on these demos, the experience wasn't disconcerting or dizzying in the slightest. Unlike the Oculus Rift, castAR isn't about replacing your entire field of view with a virtual reality--it's about inserting something in the real world that isn't there.

So when will everyone else be able to try out castAR? Technical Illusions is planning a Kickstarter later this year, and Ellsworth estimates that the glasses will cost under $200 using non-specialized components. As an innovative implementation of augmented reality, castAR is really exciting--we could see this doing for AR what the Oculus Rift has done for VR. Stay tuned for our video interview with Jeri and Rick from Maker Faire.

Update: The more I think about it, the more the castAR reminds me of zSpace's Infinite Z display. Infinite Z is a real product you can buy now, though it has been primarily adopted by designers and health care processionals as a virtual-holographic display. The big differences between castAR and zSpace are two-fold: zSpace's device only works within its 24-inch screen (creating the "framing" effect that castAR avoids with its projectors), and the Infinite Z currently costs $4000, as opposed to the $200 target for castAR.