3. Add a 3D Object

SecondLight isn’t limited to flat sheets of plastic for secondary displays.

Surface can track objects you put down on it and project information around them. Microsoft ran a scavenger hunt game at the Professional Developer Conference last week with plastic cards that had nothing but a 2D barcode on the back ; when you drop one onto a Surface, it displays a ring of images you need to match by dragging the right photo on top of the card.

SecondLight supports multi-touch and the second camera means it can detect physical objects like a real paintbrush or a simple plastic widget.

Because it can project through the usual display surface, SecondLight can project light into – and through – solid objects like a disk of injection molded plastic. A simple object would show the image on the top, so you could have a casino chip with the value shown when you put it down, or a chess piece with your face projected onto it. But add a prism inside the object and the image that SecondLight projects into it will be refracted to show along the edges of the disk like a scrolling ticker.

When the display is transparent, SecondLight can project an image into a small block of plastic – unlike a normal projection screen (simulated in the middle picture) ; the block has a prism that projects the words around its circumference.

Surface systems are going to show up in bars and restaurants, and one of the ideas is that glasses will have 2D barcode tags on so you can use them to interact with Surface ; put your drink down to see the cocktail menu, for instance. A project called SurfaceWare puts a prism into the glass that also lets SecondLight tell when you’re ready to order another drink. The prism refracts light, but only when it’s exposed to the air ; if it’s covered by a liquid – your drink – the light isn’t refracted far enough for SecondLight to see it.

A large triangular prism in the bottom of a glass would look quite stylish. It would also refract more and more light as you drink more and expose more of the prism’s surface. When you’re almost done, SecondLight could signal the bartender or pop up a message on the side of your glass asking you to tap on the screen if you want to order another.

Adding SecondLight to Surface will make the systems more expensive because of the extra projector and camera but the researchers are looking at using a single 120Hz projector to bring down the cost and make the images brighter. The current projectors can produce a clear image up to six inches above the SecondLight surface ; a motorized focus system would increase that, as would a laser projector that would keep the image in focus on multiple surfaces.

It will be about a year before we see a version of Surface for home users and SecondLight could take longer than that to make it into Surface. But multi-touch is only just making it into Windows with the upcoming Windows 7 release ; with SecondLight, you’ll get 3D gestures and images that come out beyond the display.

SurfaceWare ; the glass that knows when you want another drink