CastAR is a 3D holograph-style game display that runs through a pair of glasses. In the shorthand blurb of the gadget's Kickstarter, it's basically like that "let the Wookie win" scene in which R2-D2 and Chewbacca play a chess-style game.
Valve wasn't interested in the curious project, and released it to the departing duo, who became Technical Illusions, setting up shop in Johnson's living room. They started pulling together electronics junk to make a prototype.
"CastAR includes a very fast and highly precise tracking solution, allowing you to change your experience by holding your 3D world in place while you are free to move around," says the promotional material and, indeed, that is exactly how it works.
Playing a demo at the recent Gaming Insiders Summit, I was confronted with a floating 3D gaming world that feels significantly different to one that's on a 2D screen. It offers a sense of depth that feels tangible. The product is due to launch next September for $189, coming with glasses and a projection surface that you can well imagine being draped over the kitchen table.
The sensation of playing CastAR is novel, but nowhere near as "wow"-inducing as, say, Oculus Rift. It would be a mistake to think of these as opposing competitors for the future of game displays. CastAR is a gentler experience. It offers a 3D world that sits in front of the player, not all around.
"When you play it, you can see the other players," said Johnson. "Social gaming is social. If I am playing against you I can see your reactions. With VR you can't see anything else."
Although CastAR can run any kind of video game, the big play, at first, is going to be augmented reality table-top games. Using an RFID grid (Radio Frequency Identification) and RFID pads in game pieces, players can control the game world using a wand.
"You can track figures, playing cards, board pieces, and augment it with health bars and other types of data that are useful," said Johnson.
This is about a good deal more than goofy animations when my bishop takes your queen, or when Irkutsk is overrun with Mongolian hordes.
"You can play with your friends across country. They can see the same game, the same set-ups and you can save the game and come back to it," he explained.
Also, different players sat around the same table can see the game differently, offering a lot of interesting new takes on board games. Figurine battles like Warhammer will feature augmentations that take measurement and reckoning out of combat.
So CastAR is more than just a new display system or a funky sci-fi retro gizmo. It's a way for video games to try something new, to cross the divide into the realm of toys.
Ellsworth's experience is in designing electronic toys. Her best known work is a Commodore 64 joystick that included 30 '80s games installed, and became a darling of the gadget-hacking community.
"My background is in chip design and toy design," she said. "What they do is look for something that was really expensive a couple of years ago but there is some kind of market force that has helped the price come down."
Market changes brought about by growth and competition in smart phones have helped CastAR come into existence at an affordable price. "Cell phone cameras are very inexpensive and they have some properties that work really well for our head tracking system," she explained. "Some clever applications of optics allowed us to use these image sensors that make excellent head tracking sensors.
"Also, micro display manufacturers have been bringing sizes down considerably. We have overcome some of the issues in terms of taking a very small projector and making it work."
After the Valve split — diplomatically Johnson says it just "wasn't a good fit" — the two started work in his living room, which has now become an engineering den crammed with electronics junk.
CastAR is less like the software programming innovations that we tend to associate with inventors these days, and more like the sort of thing Doc Brown might have concocted. The glasses currently have that lovely taped-together feeling of a proper prototype.
"I live for this," said Ellsworth. "I have done very boring video compression work in the past and I don't feel really good about it. But this is one of these projects that, from day one, people say, 'oh wow, this is incredible.' That means we are really pushing the boundaries."
The Kickstarter's $400,000 goal was reached and breached within the first two days of a 30-day campaign, so the team are waiting on seeing how many of these things will need to be made for the first-roll-out.
It's clear that a tech like this is just the sort of thing that could easily work in conjunction with branded games from very powerful family entertainment companies. Ellsworth said meetings had taken place with "large companies" but that it's still early days.
Even so, a successful Kickstarter bodes well for CastAR and the developers' aspirations. The gadget could be a quirky cult favorite, but it also has the flavor of a Wii-like mass-market phenomenon. How such an eventuality would be received within the corridors at Valve towers can be well imagined.