To really put one together, though, will require advances in digital storytelling/gaming, artificial intelligence, 3D displays, human interface design, and other technologies (including the one that will make energy tangible). You may not be able to build your own holodeck anytime soon, but advancements continue to be made in key fields. A recently available computer-display technology and a soon-to-be-released game are the latest indications of progress towards making the holodeck a reality.
3D without the glasses
You've never seen your Star Trek heroes wearing funny cardboard glasses on the holodeck. But most of the general public associates 3D with red-and-blue glasses or plastic polarised lenses. High-end multimedia and optics research institutions such as NYU, MIT, and others around the world have been experimenting with autostereoscopic technologies for ten years or more. All that's required is for the screen to serve up a different image to each eye--just as a lenticular, 3D postcard does.
With a monitor, the trick is to write images that are different line by line across the screen and send the odd and even sets of lines to the left or right eye. NYU's Ken Perlin has a dandy Java demonstration of this. Developers of commercial autostereoscopic displays have been supplying the tools to the military and to scientific researchers and engineering firms with deep pockets at prices far beyond the reach of the discretionary income of mere mortals. Their cost has been out of our reach until now, that is.
3D priced for thee and me
US-based Dimension Technologies (DTI) has been selling autostereoscopic devices to researchers, engineers, and the military for more than a decade. It recently began shipping a 15-inch flat-panel display for US$1,699. This dandy little monitor goes from 2D to 3D at the touch of a button (assuming, of course, you have something 3D to display). The monitor is shipping now, though in limited production runs. DTI is working on finding partners for larger runs of the displays.
The DTI display provides an excellent 3D view. You'll need to find a sweet spot to sit in for the full experience, but the monitors are equipped with a positioning helper. To find the right viewing position, you move your head until you cannot see the red LED on the monitor. The system allows for some lateral movement of your head and body without image decay, and DTI claims that up to six different people (three sitting and three standing) can be positioned where they could all see 3D at the same time. The company has proof of concept rear-projection prototypes developed as well.
