Perceptual aspects in rendering and antialiasing of animation sequences

Karol Myszkowski, Przemyslaw Rokita and Takehiro Tawara

We consider accelerated rendering of high quality walkthrough animation sequences. To improve rendering performance we use a combination of: a hybrid ray tracing and Image-Based Rendering (IBR) technique, and a novel perception-based antialiasing technique. In our rendering solution we derive as many pixels as possible using inexpensive IBR techniques without affecting the animation quality. A perception-based spatiotemporal Animation Quality Metric (AQM) is used to automatically guide such a hybrid rendering. The Pixel Flow (PF) obtained as a by-product of the IBR computation is an integral part of the AQM. The final animation quality is enhanced by an efficient spatiotemporal antialiasing, which utilizes the PF to perform a motion-compensated filtering. The filter parameters have been tuned using the AQM predictions of animation quality as perceived by the human observer. These parameters adapt locally to the visual pattern velocity.

Some preliminary results have been presented at 10th Eurographics Workshop on Rendering held in Granada (Spain), June 21-23, 1999 (paper and color figures). More details can be found in more recent paper published in the IEEE Transactions on Visualization and Computer Graphics journal Vol. 6, No. 4, pp. 360-379. Below we present a number of walkthrough samples to compare the animation quality which was obtained using the traditional solutions, and various combinations of our techniques. Note that because of the lossy compression of the presented animation samples some perceptible information could be discarded in respect to the original animations displayed directly from non-lossy media.

Case study #1: ATRIUM

As a first case study for our walkthrough animation we selected an Atrium of the University of Aizu. The considered animation path is shown below. We marked the location of keyframes and an inbetween frame along the animation path using the following color convention:

IBR & Ray Tracing with motion-compensated filtering QuickTime movie (5MB) Half size (2MB)

IBR & Ray Tracing without any filtering QuickTime movie (7MB) Half size (2MB)

IBR only animation with motion-compensated filtering QuickTime movie (5MB) Half size (2MB)

Examples of the Animation Quality Metric responses for various Pixel Flow velocities are shown here.

Case study #2: ROOM

Ray Tracing with adaptive supersampling QuickTime movie (5MB)

Ray Tracing with adaptive supersampling and perception-based antialiasing QuickTime movie (5MB)

Raw Ray Tracing with perception-based antialiasing QuickTime movie (5MB)

IBR & Ray Tracing with perception-based antialiasing QuickTime movie (5MB)