Breaking the Frame: Novel Strategies for Interactive Computer Graphics


July 20, 2004


Benjamin Watson and David Luebke


Northwestern University; University of Virginia


We have been rethinking the fundamental sampling strategies used in interactive computer graphics. This rethinking has led to such interesting questions as, “How should we display an image in which some pixels are older than others? Do we need pixels at all? Do we even need ‘images’ in the classic sense of ‘frames in an animation’?” We will describe a novel temporally adaptive temporal sampling approach based on frameless rendering, a per-sample rendering algorithm that decouples spatial and temporal updates and thus enables very flexible adaptive spatial and temporal sampling. Closed-loop feedback guides sampling to image regions that change significantly over space or time. Adaptive reconstruction generates images for display, emphasizing older samples in static settings (resulting in sharper images) and new samples in dynamic settings (resulting in possibly blurry but up-to-date images). Measurements (using peak signal-to-noise ratio) indicate that this system produces better image streams than framed or non-adaptive frameless renderers with the same simulated sampling rates.


Benjamin Watson and David Luebke

Benjamin Watson is an Assistant Professor at the Computer Science department of Northwestern University. There he leads the Realism Lab, which strives to bring realistic complexity to interactive display. His research interests address understanding, generating, displaying, and interacting with realism, and therefore include topics such as measuring visual similarity, procedural modeling of human artifacts, temporally adaptive rendering, simplification, visualization and 3D interaction. His work has been applied to digital entertainment and training, marketing and financial intelligence, medical therapy and assessment, and education. Watson earned his Ph.D. at Georgia Tech’s GVU Center, co-chaired the Graphics Interface 2001 conference, and chaired the IEEE Virtual Reality 2004 conference. He is coauthor with David Luebke of “Level of Detail for 3D Graphics”, published by Morgan Kaufman.

David Luebke is an Assistant Professor in the Department of Computer Science at the University of Virginia. He earned his Ph.D. in Computer Science at the University of North Carolina under Frederick P. Brooks, Jr., and earned his Bachelors degree in Chemistry at the Colorado College. Professor Luebke’s principal research interest is interactive computer graphics, particularly the problem of acquiring and rendering very complex real-world scenes at interactive rates. Specific projects include polygonal level of detail (LOD), temperature-aware graphics architecture, scientific computation on graphics hardware, advanced reflectance and illumination models for real-time rendering, and image-based acquisition of real-world environments. Another project was the Virtual Monticello museum exhibit, which ran for over 3 months and helped attract over 110,000 visitors as a centerpiece of the major exhibition “Jefferson’s America and Napoleon’s France” at the New Orleans Museum of Art. Luebke is also lead author of the book “Level of Detail for 3D Graphics”.