Paul Debevec November 20, 2006

Virtual Cinematography: Postproduction Control of Viewpoint and Illumination
Paul Debevec

Abstract:
In many of today's films, much of the imagery is a combination of live-action photography and computer-generated imagery. Actors filmed in the studio are placed into distant or imagined locations, and CGI creatures and characters are added in alongside the main cast. The central challenge in combining the real and the rendered is making it look like everything was shot at the same time with the same camera. This is particularly difficult for live-action elements, since their viewpoint and lighting becomes fixed as soon as they are filmed. This talk will present emerging technologies for filming actors' performances in ways that their viewpoint and their illumination can be crafted virtually as part of the postproduction process. Examples include shooting high speed video under rapidly changing lighting conditions, filming with arrays of cameras, and using high-speed video projectors to reconstruct the actor's shape at every instance of time. These techniques not only make it easier to integrate live-action and computer-generated imagery, but give filmmakers new levels of control over lighting and composition for virtual cinematography.


Biography:
Paul Debevec is a research associate professor at the University of Southern California and the executive producer of graphics research at the USC Centers for Creative Technologies. Debevec's Ph.D. thesis (UC Berkeley, 1996) presented Facade, an image-based modeling and rendering system for creating photoreal architectural models from photographs. Using Facade he led the creation of virtual cinematography of the Berkeley campus for his 1997 film "The Campanile Movie" whose techniques were used to create virtual backgrounds in the 1999 film "The Matrix". Subsequently, Debevec developed techniques for illuminating computer-generated scenes with real-world lighting captured through high dynamic range photography, demonstrating new image-based lighting techniques in his films "Rendering with Natural Light" (1998), "Fiat Lux" (1999), and "The Parthenon" (2004); he also led the design of HDR Shop, the first widely-used high dynamic range image editing program. At USC CCT, Debevec has led the development of a series of Light Stage devices for capturing and simulating how objects and people reflect light, recently used to create realistic digital actors in films such as "Spider Man 2" and "Superman Returns". He is the recipient of ACM SIGGRAPH's first Significant New Researcher Award and a co-author of the 2005 book "High Dynamic Range Imaging" from Morgan Kaufmann. http://www.debevec.org/

Schapiro Center Davis Auditorium, 4th Floor CEPSR

Official Website: http://www.cs.columbia.edu/mice/calendars/eventDesc.php?eventID=163