USC Lab Creates 3-D Volumetric Display
In an impressive mix of visual sciences and sci-fi, the ICT Graphics Lab at USC has created a low-cost volumetric 3-D display that brings every kid's hologram dreams closer to reality. The process is not simple but can be defined through a few key concepts: spinning mirrors, high-speed DLP Projections, and very precise math that figures out the correct axial perspective needed for a 360-degree image (even taking into account a viewer's positioning.)
Different companies have been trying to create a viable 3-D technology for years, but have found several barriers in their way: small viewing areas, high costs and the viewer disconnect with blurry optical illusions. The most recent attempts have included Helio Display that recreate 2-D projections into floating 3-D illusions, as well as Jeff Han’s Holodust, which involves infrared lasers 'lighting up' particles in space.
But the USC project is different and way more realistic. When projecting video frames into a rapidly spinning mirror, close to 5,000 individual images are reflected every second within the surface area and come together to create a real-space three-dimensional object. Because the images projected from the mirror jump out "toward multiple viewpoints in space," the USC team created a formula that renders individual projections at different heights and traces each projected beam back to the display area to find the correct position of the viewer.
The system also updates itself in real time (at 200Hz), adjusting to the height and distance of the viewer, producing an image that will "stay in place," (or rather, that "adjusts its projected perspective.") In this way, every person in a room will be able to have a correct POV of a holographic image, like that of the TIE fighters in the image above. It also allows for the correct image occlusion as well as the appropriate image shading necessary for each item. More importantly, it enables simultaneous viewing -- no one will need to use dorky, uncomfortable glasses to see them battle in mid air.
By Jose Fermoso, Wired
