Space-Time Hierarchical Radiosity

Abstract

This paper presents a new hierarchical simulation algorithm allowing the calculation of radiosity solutions for time-dependent scenes where all motion is known a priori. Such solutions could, for instance, be computed to simulate subtle lighting effects (indirect lighting) in animation systems, or to obtain highquality synthetic image sequences to blend with live action video and film. We base our approach on a Space-Time hierarchy, adding a life span to hierarchical surface elements, and present an integrated formulation of Hierarchical Radiosity with this extended hierarchy. We discuss the expected benefits of the technique, review the challenges posed by the approach, and propose first solutions for these issues, most notably for the space-time refinement strategy. We show that a short animation sequence can be computed rapidly at the price of a sizeable memory cost. These results confirm the potential of the approach while helping to identify areas of promising future work.

Perception-guided global illumination solution for animation rendering

“…Early solutions [4,8,17] were embedded into the progressive radiosity framework and relied on shooting the corrective energy (possibly negative) to the scene regions affected by the environment changes. Much better performance was obtained for more recently introduced techniques that are based on hierarchical radiosity [6,24,5,21]. A line-space hierarchy proposed by Drettakis and Sillion [6] enables fast identification of links affected by a scene modification, and leads to image updates at interactive rates for moderately complex environments.…”

“…The problem of storing shafts was recently reduced by Schoeffel and Pomi [24], who store shafts only locally for regions affected by geometry changes. Damez and Sillion [5] explicitly incorporated time in the hierarchical radiosity framework and showed substantial improvements in the rendering performance of animated sequences. However, this was achieved at the expense of a significant increase of memory requirements which become impractical for complex scenes.…”

Space‐Time Hierarchical Radiosity with Clustering and Higher‐Order Wavelets

“…We have previously presented a preliminary version of the space‐time hierarchical radiosity algorithm [2]. We present here a fully developed algorithm.…”

Animating radiosity environments through the Multi‐Frame Lighting Method

“…Strategies like progressive refinements methods [2][3][4] or hierarchical radiosity [5][6][7] have been developed with the goal of quickly updating changes in illumination for a given demand. In the case of non-interactive radiosity animations, [8][9][10][11][12] where all time-dependent parameters can be known a priori, requirements are not the same as in the interactive case: there is not a high compromise on speeding updates of single frames. However, a large number of frames must be computed, maintaining a high-quality level of accuracy.…”