Frequency analysis and sheared reconstruction for rendering motion blur

Motion blur is crucial for high-quality rendering, but is also very expensive. Our first contribution is a frequency analysis of motion-blurred scenes, including moving objects, specular reflections, and shadows. We show that motion induces a shear in the frequency domain, and that the spectrum of moving scenes can be approximated by a wedge. This allows us to compute adaptive space-time sampling rates, to accelerate rendering. For uniform velocities and standard axis-aligned reconstruction, we show that the product of spatial and temporal bandlimits or sampling rates is constant, independent of velocity. Our second contribution is a novel sheared reconstruction filter that is aligned to the first-order direction of motion and enables even lower sampling rates. We present a rendering algorithm that computes a sheared reconstruction filter per pixel, without any intermediate Fourier representation. This often permits synthesis of motion-blurred images with far fewer rendering samples than standard techniques require.
United States. Office of Naval Research. Young Investigator Program (N00014-07-1-0900)
United States. Office of Naval Research. (Grant number N00014-09-1-0741)
National Science Foundation (U.S.). Graduate Research Fellowship Program
National Science Foundation (U.S.). (Grant number 0446916)
National Science Foundation (U.S.). (Grant number 044756)
National Science Foundation (U.S.). (Grant number 0701775)
Alfred P. Sloan Foundation Fellowship
Microsoft Corporation. New Faculty Fellowship