Image courtesy of Deron Yamada. © 2004 DYA367.

Understanding light is key to making art and movies, in particular. The old Hollywood masters knew how to create mood with light, enhance beauty with it and create a sense of place. Poorly understood, light can ruin creative effort and confuse an image. Real light is wonderful to work with in the hands of a lighting master. When you think about it, light is our main interface with life, supplemented by sound and bounded by touch.

Today we work as much with virtual as real light… perhaps more. And understanding virtual light is more difficult than understanding the visual impact of real photons. But understanding virtual light brings enormous power over image. Look at what Photoshop tools can do to a snapshot, refining a drab, ugly image into a vibrant beautiful final -- and that's just the beginning. Light reveals information and that information can be recorded and used in new ways to create images that never existed. As we move deeper into our understanding of light, amazing things are becoming possible and one man, in particular, is blazing our way into that light. Dr. Paul Debevec.

Debevec is associate director of graphics research at the University of Southern California's Institute for Creative Technologies. More than that, he is a true pioneer in many technologies that, once discovered, have become part of the pallet of every 3D artist and digital filmmaker. The large studios pay big bucks to be the first to use Dr. Debevec's inventions to enhance their vfx heavy films like the Matrix and Spider-Man franchises and King Kong. Let's take a look at what he's been doing lately.

Dr. Paul Debevec's lastest research includes designing a working prototype of an easy to build, 3-D display system using a standard video projector. Unless noted, all images © 2004 University of Southern California.

A Realtime 3-D Display in the Round
Debevec's team at the ICT has designed a working prototype of a reasonably easy to build, 3-D display system using a standard video projector, which has been modified to project over 4,000 frames/second. Their original design has a number of advantages over typical 3-D display technologies:

• omnidirectional -- It generates 3-D images in the round, so you can walk around it seeing it from all sides.

• autostereoscopic -- which means you don't need to wear any kind of glasses to get the effect… a big advantage.

• animated/interactive -- the image can be updated 200 times a second allowing for fine detail interaction and full animation.

The main disadvantage is that in its present state of development it is monochromatic. The modifications on the video projector necessary to output the tremendous amount of information needed to reproduce such an image requires that all the color channels be repurposed to the main mission, leaving color behind. However, this is not a permanent problem as solutions are on the horizon using three -chip video projectors.

Dr. Paul Debevec.

The 3-D images are created by projecting super high-speed video onto an almost invisible spinning mirror. The projected images are synchronized so that as the mirror spins, it reflects a different image towards each potential viewing angle, accurately portraying the object from each perspective.

According to Debevec, "Our rendering approach is capable of recreating real scenes as well as virtual ones, with correct occlusion, horizontal and vertical perspective and shading." I did notice that tilting one's head causes some minor distortion in the image.

Debevec expressed optimism about ever getting rid of the confining mirror. Actually, looking at the image, seemingly floating in space as you walk around it, gives one an uncanny but cool feeling. You want to reach out and touch it, which is probably why the image is created inside a glass enclosure. I imagine the spinning mirror could be a bit painful if one lost his head.

Debevec explained that in order to succeed, the next-generation of 3-D displays must begin to represent the physical world more accurately and in the round. He's currently working on a color display using a three-chip video projector, experimenting with tent shaped mirrors to create a more solid and satisfying image, reducing the uncanny effect. He added, "The Holy Grail in this arena is to find a good solid state approach to make light wag back and forth like our spinning mirror does today." That one is a ways off.