Obama 3D in the National Portrait Gallery
The University of Southern California's Institute for Creative Technologies ( ICT) was part of a Smithsonian-led team that created 3D portraits of President Barack Obama. The portraits include a digital and 3-D printed bust and life mask. Both were on display at the first ever White House Maker Faire on June 18.
The data and the printed models are intended to become part of the collection of the Smithsonian's National Portrait Gallery.
The team scanned the president earlier this year using two distinct 3-D documentation processes. Experts from ICT used their Light Stage face scanner to capture high-resolution shape and reflectance properties of the president's face in seconds. Next, a Smithsonian team used handheld 3-D scanners and traditional digital cameras to record peripheral 3-D data to create an accurate bust.
"The Smithsonian's 3-D presidential portrait project represents the first deployment of a Light Stage system designed for mobile use and the fastest scanning session ever conducted by ICT's graphics laboratory," said Paul Debevec, ICT's chief visual officer and the inventor of the Light Stage technologies. "The Smithsonian Institution had an ambitious vision to create the first ever 3-D printed model of a president and it was an honor to contribute our technology to the process."
ICT's Light Stage: How it Works
USC ICT's Mobile Light Stage has 50 light sources (each with a cluster of 12 bright white LEDs) arranged similarly to the stars of the American flag. Each light is its own custom-designed networked computer and can produce any brightness or polarization of light.
Each light stage scan is a flurry of 10 photos taken in about a second by eight cameras as the lights emit different gradients of intensity and polarization, generating 80 photographs tightly zoomed in on the face from all angles. At the end, six auxiliary cameras take one photo each under flat lighting seeing down to the shoulders and rest of the bust.
Computer algorithms identify corresponding points on the face in the different viewpoints, allowing a rough 3-D model to be triangulated from the correspondences. The differently polarized lighting conditions allow the shine off of the skin's surface to be imaged separately from the light, which scatters beneath the skin and the play of light over the skin's shiny component records minute texture details at the level of skin pores and fine creases to a tenth of a millimeter accuracy.
The final 3-D model covering the face from ear to ear, and forehead to tie, is a digital surface mesh with several million tiny triangles and corresponding 30-megapixel digital images of the face's texture and shine.
ICT is an Army-sponsored, University Affiliated Research Center, managed by the U.S. Army Research Laboratory and is devoted to advancing the art and science of simulation. Institute research and development efforts can be seen throughout the Army -- to include a virtual reality therapy for treating post-traumatic stress, interactive virtual humans for training and education, and tools and techniques for creating low-cost, immersive head mounted displays. The Army funds much of the basic research that goes into the development of the Light Stage systems.