Imagine a multi-user augmented reality experience that feels natural and can scale to any size you want, without common pitfalls like dizziness or an expensive price tag. That's what hardware hacker Jeri Ellsworth and her team at Technical Illusions are shooting for with CastAR. Gizmag snatched a chance to play with the system at World Maker Faire 2013, where it won the Editor’s Choice and Educator’s Choice awards.

CastAR setup

With a CastAR system you still can perceive your natural surroundings, but overlaid with augmented 3D visuals. You can peer over walls by lifting your head, see new perspectives by turning, and crouch by ... crouching, in short, exactly what you’d expect to happen.

The complete setup includes 3D projector glasses, a reflective screen about the size of a poster, a wand-like handheld controller, plus other IR-LED and RFID tracking components. The glasses are fitted with HD 720p projectors, one for each eye, and project in 24 bit color which bounces off a retro-reflective mat and returns to each eye in 3D. Light is mostly reflected directly back at each user, so multiple users can play without getting crosstalk between views.

Head tracking occurs with an accuracy of 0.07 mm, with IR sensors on each side of the glasses, and IR-LEDs on the wand, the mat, and on any objects you want to track. Because the position of the head is tracked so accurately, it fuels additional applications such as 3D audio or using the head movements to directly control steering. The CastAR team implemented the latter in a flight simulator demo, and we found movement intuitive and instinctive.

Jeri Ellsworth demonstrating the CastAR at World Maker Faire 2013

But what can you do with it?

The average person will use a standard app for the system, but nearly everything about the CastAR will be open and implemented into an API for users to create their own applications. Additionally, it takes about five minutes to create a game using the Unity game engine presets, so the designers imagine fan-created levels being shared. But in addition to gaming, it clearly has other applications in education, data visualization, manufacturing and design.

The retro-reflective material also adds to the flexibility of the system. It’s cheap, so while a user would start with the same size piece as everyone else, they could buy enough to coat a wall, or set up multiple systems around a location, each screen having its own unique set of tracking points. Additionally, the screen can be arranged however is most logical: laid flat for board games, put on a wall for a FPS, rolled into a semicircle, or held at a right angle, as it was used in our demo.

CastAR glasses projecting light onto a bent retro-reflective screen

In our interview, Ellsworth and the software head Rick Johnson shared software ideas that they’ve dreamt up and that potential end users have created. A favorite of Johnson's, a D & D player, is an augmented tabletop RPG where the dungeonmaster could virtually “stamp” out a campaign by using real objects encoded with a marker to place obstacles, monsters, and loot. With each player only able to see their own visuals, the DM could see the whole scenario, while players would have a “fog of war” over what they haven’t explored. This concept could be generalized to other board games, especially with end users adding their own figurines enabled with cheap microcontrollers.

Ellsworth related the story of a researcher who demoed CastAR at a previous MakerFaire and instantly realized the potential of the system for data visualization in his lab. Studying shark and turtle interactions in a 3D space, he needed a way for his lab employees to visualize and collaborate in a group. After returning to his lab he coded his own app, which the CastAR team already has tried out.

The Gizmag demo experience

Gizmag’s first reaction was of how natural the visuals felt. There’s little latency in the system. We could crouch down to the level of the tabletop and still get a reflection back to my glasses. We tried both a Jenga-style game using the wand controller, chosen by the team for its simplicity to those not familiar with video games, and
Angry Bots, a top-down shooter that uses the Unity engine.

Gizmag playing the Jenga-like demo with the CastAR (the handheld glasses are a prototype, the lighted surface just a lamp)

Strangely, the experience wasn’t as overpoweringly awesome as we were expecting, but that might be because the system did its job so well. Instinctively, one would expect the surroundings to behave a certain way, so when you move your head sideways, you expect what you're looking at to move in the same degree. There was nothing to analyze, nothing to ignore because it was uncomfortable or unexpected.

So ultimately its natural comfortableness is probably a selling point, given games and applications that still drive home completely how different it is. Additionally, Ellsworth reports that those who have demoed the system don't report headaches or nausea — you don’t have to go cross-eyed to use it — and we had a similar experience.

Production plans

Technical Illusions will try to bring the CastAR to market with Kickstarter and plan to implement it for PC and Android, with iOS and Linux further on the horizon. The launch date is expected to be October 15th, with an anticipated pledge between US$200 and $250. Should the launch succeed, shipping could begin in November 2014.

Below is footage from a CastAR demo of what Star Wars holographic chess might look like.

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