ICT

GL

A Median Cut Algorithm for Light Probe Sampling

SIGGRAPH 2005 Poster

Paul Debevec

USC Institute for Creative Technologies

Published in: Reinhard, Ward, Pattanaik, and Debevec, High Dynamic Range Imaging: Acquistion, Display, and Image-Based Lighting,
Ch. 9, "Image-Based Lighting", Morgan-Kaufmann, 2005, pp. 430-433.

Abstract:

We present a technique for approximating a light probe image as a constellation of light sources based on a median cut algorithm. The algorithm is simple to implement, runs efficiently, and can realistically represent a complex lighting environment with as few as 64 point light sources.

Material:

SIGGRAPH 2005 Poster Abstract:

MedianCutSampling.pdf, 3.0 MB. ( Adobe Acrobat )

Supplemental Images Poster Abstract:

MedianCutSampling_plate.pdf, 5.4 MB. ( Adobe Acrobat )

Implementations:

There is an implementation of the Median Cut sampling algorithm as an HDR Shop 1.0 plugin in Francesco Banterle's Banty's Toolkit beta 1.1, which produces a simple text file with the light parameters.
The algorithm is also implemented in Jeremy Pronk's Image-Based Lighting Tools package, with support for Maya and Mental Ray.