Chasing the green flash: a global illumination solution for inhomogeneous media

ABSTRACT

Several natural phenomena, such as mirages or the green flash, are owed to inhomogeneous media in which the index of refraction is not constant. This makes the light rays travel a curved path while going through those media. One way to simulate global illumination in inhomogeneous media is to use a curved ray tracing algorithm, but this approach presents some problems that still need to be solved. This paper introduces a full solution to the global illumination problem, based on what we have called curved photon mapping, that can be used to simulate several natural atmospheric phenomena. We also present a model of the Human Visual System (HVS) to display images in a more realistic way, taking into account how we perceive luminances in a real-world scene. This is of special interest in the green flash effect, where some of the perceived green is owed to bleaching of the photoreceptors in the human eye.

REFERENCES

• 1: Arvo, J., 1986. Backward ray tracing, in Developments in ray tracing, ACM SIGGRAPH '86 Seminar Notes, volume 12.
• 2: Marc Berger , Terry Trout , Nancy Levit, Ray Tracing Mirages, IEEE Computer Graphics and Applications, v.10 n.3, p.36-41, May 1990 [doi>10.1109/38.55151]
• 3: Born, M. and WOLF, E. Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light. Cambridge University Press, ISBN 0-521-642221, 2002.
• 4: Bruton, D. 1996 Optical determination of atmospheric temperature profiles, submitted to the Office of Graduate Studies of Texas A&M University, 1996.
• 5: Burden, R. L. and Douglas Faires J. 1995. Numerical Analysis PWS, Boston, USA.
• 6: Cornsweet, T. N. 1970. Visual Perception. New York. Academic Press. http://cvision.ucsd.edu
• 7: Harwert, R. S. and Sperling, H. B. 1971. Prolonged color blindness induced by intense spectral light in reshus monkeys. Science, 174, 520--523.
• 8: Harwert, R. S. and Sperling, H. B. 1975. Effects of intense visible radiation on the increment threshold spectral sensitivity of the rhesus monkey eye. Vision Research, 15, 1193--1204. Hunt, R.W.G. 1995 The reproduction of colour, Chapter 31. Fountain Press, England.
• 9: Henrik Wann Jensen, Realistic image synthesis using photon mapping, A. K. Peters, Ltd., Natick, MA, 2001
• 10: Lafortune, E. P. and Willems, Y. D. 1993. Bidirectional path tracing. In Compugraphics '93, 95--104.
• 11: Geisler, W. S. 1978. The effects of photopigment depletion on brightness and threshold. Vision Res., 18, 269--278.
• 12: Geisler, W. S. 1979. Evidence for the equivalent background hypothesis in cones. Vision Res., 19, 799--805.
• 13: Andrew S. Glassner, An introduction to ray tracing, Academic Press Ltd., London, UK, 1989
• 14: Andrew S. Glassner, Principles of Digital Image Synthesis, Morgan Kaufmann Publishers Inc., San Francisco, CA, 1994
• 15: Groeller, E. 1995. Nonlinear ray tracing: visualizing strange worlds, Visual Computer 11(5), Springer Verlag, 1995, 263--274.
• 16: Minnaert, M.G.J. 1993. Light and color in the outdoors, Springer-Verlag 1993.
• 17: F. Kenton Musgrave, A Note on Ray Tracing Mirages, IEEE Computer Graphics and Applications, v.10 n.6, p.10-12, November 1990 [doi>10.1109/38.62692]
• 18: Forest Kenton Musgrave, Methods for realistic landscape imaging, Yale University, New Haven, CT, 1993
• 19: Nishita, T. 1998. Light scattering models for the realistic rendering of natural scenes, Proceedings of rendering Techniques '98, 1--10.
• 20: Sumanta N. Pattanaik , Jack Tumblin , Hector Yee , Donald P. Greenberg, Time-dependent visual adaptation for fast realistic image display, Proceedings of the 27th annual conference on Computer graphics and interactive techniques, p.47-54, July 2000 [doi>10.1145/344779.344810]
• 21: Preetham, A. J. 2003 Modeling Skylight and Aerial Perspective. ATI Research, ACM SIGGRAPH 2003
• 22: Rushton, W.A.H. 1963. The density of chlorolabale in the foveal cones of a protanope. Journal of Physiology'63, 168, 360--373.
• 23: Rushton, W.A.H. 1965. Cone pigment kinetics in the deuteranope. Journal of Physiology'65, London, 176, 38--45.
• 24: Rushton, W.A.H. 1972. Pigments and signals in colour vision. In Journal of Physiology'72, London, 220, 1--21P.
• 25: Rushton, W.A.H. and Henry, G. H., 1968. Bleaching and regeneration of cone pigments in man. Vision Research 8, 617--631.
• 26: Serón, F. J., Gutiérrez, D., Gutiérrez, G. and Cerezo, E. 2002. An implementation of a curved ray tracer for inhomogeneous atmospheres. In ACM Transactions on Graphics, 2002.
• 27: Smith, V. C., Pokorny, J. and Diddie, K. R. 1988. Color matching and the Stiles-Crawford effect in observers with early age-related macular changes. Journal of the Optical Society of America A, Volume 5, Issue 12, 2113-December 1988.
• 28: Sperling, H. G. 1986. Intense spectral light induced cone specific lesions of the retina and the effects of anesthesia. In Hazards of Light eds. Cronly-Dillon, J. R. et al., pp. 153--167. Oxford: Pergamon.
• 29: Jos Stam , Eric Languénou, Ray tracing in non-constant media, Proceedings of the eurographics workshop on Rendering techniques '96, p.225-ff., December 1996, Porto, Portugal
• 30: Vander Werf, S. Y., Günther, G. P. and Lehn, W. H. 2003. Novaya Zemlya effects and sunsets. Applied Optics, Vol. 42, No. 3, 20-1-2003
• 31: Veach, E. and Guibas, L. 1994. Bidirectional estimators for light transport. In Fifth Eurographics Workshop on Rendering, 1994, 147--162.
• 32: Walraven, J. 1981. Perceived colour under conditions of chromatic adaptation: evidence for gain control by mechanisms. Vision Res., 21, 611--630.
• 33: Gregory Ward Larson , Holly Rushmeier , Christine Piatko, A Visibility Matching Tone Reproduction Operator for High Dynamic Range Scenes, IEEE Transactions on Visualization and Computer Graphics, v.3 n.4, p.291-306, October 1997 [doi>10.1109/2945.646233]
• 34: Wyszecki, G. and Stiles, W. S. 1982. Color Science: Concepts and Methods, Quantitative Data and Formulae. John Wiley and Sons, 2 edition.
• 35: Young, A. T. 2000. Visualizing sunsets III. Visual adaptation and green flashes, Journal of the Optical Society of America A, vol. 17, pp. 2129--2139. December 2000

INDEX TERMS

Keywords:
global illumination, inhomogeneous media, natural phenomena, photon mapping, realism, rendering