A Reconstruction Filter for Plausible Motion Blur.
McGuire, Hennessy, Bukowski, and Osman, I3D 2012

This paper describes a novel filter for simulating motion blur phenomena in real time by applying ideas from offline stochastic reconstruction. The filter operates as a 2D post-process on a conventional framebuffer augmented with a screen-space velocity buffer. We demonstrate results on video game scenes rendered and reconstructed in real-time on NVIDIA GeForce 480 and Xbox 360 platforms, and show that the same filter can be applied to cinematic post-processing of offline-rendered images and real photographs. The technique is fast and robust enough that we deployed it in a production game engine used at Vicarious Visions.

I've been preparing clean, easy-to-use versions of popular graphics research and education data for distribution. About half of the data is available now and the rest will be coming online throughout the winter and spring.

The Alchemy Screen-Space Ambient Obscurance Algorithm.
McGuire, Osman, Bukowski, and Hennessy, HPG 2011

Ambient obscurance (AO) produces perceptually important illumination effects such as darkened corners, cracks, and wrinkles; proximity darkening; and contact shadows. We present the AO algorithm from the Alchemy engine used at Vicarious Visions in commercial games. It is based on a new derivation of screen-space obscurance for robustness, and the insight that a falloff function can cancel terms in a visibility integral to favor efficient operations. Alchemy creates contact shadows that conform to surfaces, captures obscurance from geometry of varying scale, and provides four intuitive appearance parameters: world-space radius and bias, and aesthetic intensity and contrast. The algorithm estimates obscurance at a pixel from sample points read from depth and normal buffers. It processes dynamic scenes at HD 720p resolution in about 4.5 ms on Xbox 360 and 3 ms on NVIDIA GeForce580.

Colored Stochastic Shadow Maps.
McGuire and Enderton, I3D 2011

This paper extends the stochastic transparency algorithm that models partial coverage to also model wavelength-varying transmission. It then applies this to the problem of casting shadows between any combination of opaque, colored transmissive, and partially covered (i.e., α-matted) surfaces in a manner compatible with existing hardware shadow mapping techniques. Colored Stochastic Shadow Maps have a similar resolution and performance profile to traditional shadow maps, however they require a wider filter in colored areas to reduce hue variation.

Subpixel Reconstruction Antialiasing.
Chajdas, McGuire, and Luebke, I3D 2011

We introduce a novel post-processing algorithm that synthesizes shading quality close to 16x shading quality using only 1x shading under both deferred and forward rendering, in 1-2 ms per 1920x1080 frame.

A Local Image Reconstruction Algorithm for Stochastic Rendering.
Shirley, Aila, Cohen, Enderton, Laine, Luebke and McGuire, I3D 2011

Stochastic renderers produce unbiased but noisy images of scenes that include the advanced camera effects of motion and defocus blur and possibly other effects such as transparency. We present a simple algorithm that selectively adds bias in the form of image space blur to pixels that are unlikely to have high frequency content in the final image. For each pixel, we sweep once through a fixed neighborhood of samples in front to back order, using a simple accumulation scheme. We achieve good quality images with only 16 samples per pixel, making the algorithm potentially practical for interactive stochastic rendering in the near future.