BELCOUR, Laurent; BALA, Kavita; SOLER, Cyril

doi:10.1145/2629490

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License

BELCOUR, Laurent
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Laboratoire Photonique, Numérique et Nanosciences [LP2N]
Melting the frontiers between Light, Shape and Matter [MANAO]

BALA, Kavita
Program of Computer Graphics [PCG]

SOLER, Cyril
Models and Algorithms for Visualization and Rendering [MAVERICK]

Language

Article de revue

This item was published in

ACM Transactions on Graphics. 2014-08-01, vol. 33, n° 5, p. Article No. 163

Association for Computing Machinery

Abstract

Une nouvelle analyse locale de la diffusion et de l'absorption de la lumière dans l'espace de Fourier est combinée avec le tracé de covariance et permet une estimation rapide du contenu fréquentiel local; cette approche permet l'amélioration de nombreux algorithmes de rendu de milieux participants tels que Progressive Photon Beams et l'integration d'effets de diffusion simple et l'échantillonnage et la reconstruction d'effets de simple diffusion simple en espace image.Read less <

English Abstract

Rendering participating media requires significant computation, but the effect of volumetric scattering is often eventually smooth. This article proposes an innovative analysis of absorption and scattering of local light fields in the Fourier domain and derives the corresponding set of operators on the covariance matrix of the power spectrum of the light field. This analysis brings an efficient prediction tool for the behavior of light along a light path in participating media. We leverage this analysis to derive proper frequency prediction metrics in 3D by combining per-light path information in the volume.We demonstrate the use of these metrics to significantly improve the convergence of a variety of existing methods for the simulation of multiple scattering in participating media. First, we propose an efficient computation of second derivatives of the fluence, to be used in methods like irradiance caching. Second, we derive proper filters and adaptive sample densities for image-space adaptive sampling and reconstruction. Third, we propose an adaptive sampling for the integration of scattered illumination to the camera. Finally, we improve the convergence of progressive photon beams by predicting where the radius of light gathering can stop decreasing. Light paths in participating media can be very complex. Our key contribution is to show that analyzing local light fields in the Fourier domain reveals the consistency of illumination in such media and provides a set of simple and useful rules to be used to accelerate existing global illumination methods.Read less <

URI

https://oskar-bordeaux.fr/handle/20.500.12278/182025

DOI

http://dx.doi.org/10.1145/2629490

ANR Project

Analyse des opérateurs de transport lumineux et applications - ANR-11-BS02-0006

Origin

Hal imported

Collections

Laboratoire Photonique, Numérique et Nanosciences (LP2N) - UMR 5298