A Comparison of Techniques for Approximating Full Image-Based Lighting

Bidragets oversatte titel: En sammenligning af teknikker til approksimering af ægte billed-baseret lyslægning

Claus B. Madsen, Rune Elmgaard Laursen

Publikation: Bidrag til bog/antologi/rapport/konference proceedingKonferenceartikel i proceedingForskning

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Resumé

Light probes, or environment maps, are used extensively in computer graphics for visual effects involving rendering virtual objects into real scenes (Augment Reality). A light probe is a High Dynamic Range omni-directional image covering all directions on a sphere at some location. Each pixel in the light probe image measures the incident radiance at the light probe acquisition point. The figure above shows an example of a light probe image in the longitude-latitude mapping, (similar to an atlas mapping of the Earth). Using the light probe information a virtual object can be rendered with correct scene illumination and inserted into images of the scene with credible shading, reflections and shadows. Rendering virtual objects with light probe information is a very time consuming process. Therefore several techniques exist which attempt to approximate the light probe with a set of directional light sources, the number of which can be chosen to find a suitable compromise between rendering speed and approximation accuracy. This paper evaluates four such approximation techniques in terms of how accurately they perform the approximation as a function of the number of directional light sources. We demonstrate that one of the four techniques is significantly better than the rest when the number of light sources is less than around 50. In general this particular method achieves the same performance as the 3 others with only half the number of light sources.
OriginalsprogEngelsk
TitelProccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark
RedaktørerSøren Ingvor Olsen
Antal sider8
Publikationsdato2006
Sider53-60
StatusUdgivet - 2006
Begivenhed15th Danish Conference on Pattern Recognition and Image Analysis - Copenhagen, Danmark
Varighed: 24 aug. 200625 aug. 2006
Konferencens nummer: 15

Konference

Konference15th Danish Conference on Pattern Recognition and Image Analysis
Nummer15
LandDanmark
ByCopenhagen
Periode24/08/200625/08/2006

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light beams
illuminating
light sources
approximation
computer graphics
longitude
radiance
dynamic range
acquisition
coverings
illumination
pixels

Citer dette

Madsen, C. B., & Laursen, R. E. (2006). A Comparison of Techniques for Approximating Full Image-Based Lighting. I S. I. Olsen (red.), Proccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark (s. 53-60)
Madsen, Claus B. ; Laursen, Rune Elmgaard. / A Comparison of Techniques for Approximating Full Image-Based Lighting. Proccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark. red. / Søren Ingvor Olsen. 2006. s. 53-60
@inproceedings{759508f08a8011dbbb3d000ea68e967b,
title = "A Comparison of Techniques for Approximating Full Image-Based Lighting",
abstract = "Light probes, or environment maps, are used extensively in computer graphics for visual effects involving rendering virtual objects into real scenes (Augment Reality). A light probe is a High Dynamic Range omni-directional image covering all directions on a sphere at some location. Each pixel in the light probe image measures the incident radiance at the light probe acquisition point. The figure above shows an example of a light probe image in the longitude-latitude mapping, (similar to an atlas mapping of the Earth). Using the light probe information a virtual object can be rendered with correct scene illumination and inserted into images of the scene with credible shading, reflections and shadows. Rendering virtual objects with light probe information is a very time consuming process. Therefore several techniques exist which attempt to approximate the light probe with a set of directional light sources, the number of which can be chosen to find a suitable compromise between rendering speed and approximation accuracy. This paper evaluates four such approximation techniques in terms of how accurately they perform the approximation as a function of the number of directional light sources. We demonstrate that one of the four techniques is significantly better than the rest when the number of light sources is less than around 50. In general this particular method achieves the same performance as the 3 others with only half the number of light sources.",
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Madsen, CB & Laursen, RE 2006, A Comparison of Techniques for Approximating Full Image-Based Lighting. i SI Olsen (red.), Proccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark. s. 53-60, 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Danmark, 24/08/2006.

A Comparison of Techniques for Approximating Full Image-Based Lighting. / Madsen, Claus B.; Laursen, Rune Elmgaard.

Proccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark. red. / Søren Ingvor Olsen. 2006. s. 53-60.

Publikation: Bidrag til bog/antologi/rapport/konference proceedingKonferenceartikel i proceedingForskning

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AU - Laursen, Rune Elmgaard

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N2 - Light probes, or environment maps, are used extensively in computer graphics for visual effects involving rendering virtual objects into real scenes (Augment Reality). A light probe is a High Dynamic Range omni-directional image covering all directions on a sphere at some location. Each pixel in the light probe image measures the incident radiance at the light probe acquisition point. The figure above shows an example of a light probe image in the longitude-latitude mapping, (similar to an atlas mapping of the Earth). Using the light probe information a virtual object can be rendered with correct scene illumination and inserted into images of the scene with credible shading, reflections and shadows. Rendering virtual objects with light probe information is a very time consuming process. Therefore several techniques exist which attempt to approximate the light probe with a set of directional light sources, the number of which can be chosen to find a suitable compromise between rendering speed and approximation accuracy. This paper evaluates four such approximation techniques in terms of how accurately they perform the approximation as a function of the number of directional light sources. We demonstrate that one of the four techniques is significantly better than the rest when the number of light sources is less than around 50. In general this particular method achieves the same performance as the 3 others with only half the number of light sources.

AB - Light probes, or environment maps, are used extensively in computer graphics for visual effects involving rendering virtual objects into real scenes (Augment Reality). A light probe is a High Dynamic Range omni-directional image covering all directions on a sphere at some location. Each pixel in the light probe image measures the incident radiance at the light probe acquisition point. The figure above shows an example of a light probe image in the longitude-latitude mapping, (similar to an atlas mapping of the Earth). Using the light probe information a virtual object can be rendered with correct scene illumination and inserted into images of the scene with credible shading, reflections and shadows. Rendering virtual objects with light probe information is a very time consuming process. Therefore several techniques exist which attempt to approximate the light probe with a set of directional light sources, the number of which can be chosen to find a suitable compromise between rendering speed and approximation accuracy. This paper evaluates four such approximation techniques in terms of how accurately they perform the approximation as a function of the number of directional light sources. We demonstrate that one of the four techniques is significantly better than the rest when the number of light sources is less than around 50. In general this particular method achieves the same performance as the 3 others with only half the number of light sources.

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Madsen CB, Laursen RE. A Comparison of Techniques for Approximating Full Image-Based Lighting. I Olsen SI, red., Proccedings: 15th Danish Conference on Pattern Recognition and Image Analysis, Copenhagen, Denmark. 2006. s. 53-60