Audience interaction with ‘hologram’ enabled by spinning-mirror system

The Institute for Creative Technologies (ICT) at the University of Southern California (Los Angeles, CA) has developed a “hologram-like” 3-D videoconferencing system. To an assembled audience, the system displays a dynamic, three-dimensional volumetric image of the speaker’s head in real time and enables two-way communication between the display and observers.

Behind the scenes, a high-speed projector projects patterned light onto the face of the remote speaker at 120 frames/s. Meanwhile, two video cameras record the changing pattern of light on the face from slightly different points of view. From this, a computer reconstructs the 3-D shape of the face 30 times per second, and then by texture mapping that geometry, produces a 3-D model that updates at the frame rate of the video. This image is projected onto a flat brushed aluminum surface molded into the shape of an upside-down “V,” which spins at 15 times per second–thus providing 30 passes of the surface every second. Each observer gets a different view of the speaker’s face–as does every viewer’s left and right eye. What the speaker sees is a flat screen showing video of the viewing audience. Thus, the speaker can interact with specific audience members. At a recent tade show, Paul Debevec, research associate professor and associate director of graphics at ICT, explained how the system operated at a recent trade show (see video at www.laserfocusworld.com/articles/348690). The video shows a glass cage surrounding the “hologram” that, according to the researchers, prevented curious observers from getting too close and clipping their fingers on the spinning mirror. Once the system is further refined, they expect to be able to do away with the glass. Contact Paul Debevec at [email protected].