Ray Tracing in Non-Constant Media
In this paper, we explore the theory of optical deformations due to continuous variations of the refractive index of the air, and present several efficient implementations. We introduce the basic equations from geometrical optics, outlining a general method of solution. Further, we model the fluctuations of the index of refraction both as a superposition of blobs and as a stochastic function. Using a well known perturbation technique from geometrical optics, we compute linear approximations to the deformed rays. We employ this approximation and the blob representation to efficiently ray trace non linear rays through multiple environments. In addition we present a stochastic model for the ray deviations derived from an empirical model of air turbulence. We use this stochastic model to precompute deformation maps.
KeywordsForce Field Computer Graphic Geometrical Optic Stochastic Function IEEE Computer Graphic
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- 1.J. Arvo. “Backward Ray Tracing”. In SIGGRAPH ’86: Course Notes 12: Developments in Ray Tracing. SIGGRAPH, Atlanta, Georgia, 1986.Google Scholar
- 4.A. Glassner. “Space Subdivision for Fast Ray Tracing”. IEEE Computer Graphics and Applications, 4(10):15–22, October 1984.Google Scholar
- 9.F. K. Musgrave. “Prisms and Rainbows: A Dispersion Model for Computer Graphics”. In Proceedings of Graphics Interface ’89, June 1989.Google Scholar
- 11.J. C. Owens. “Optical Refractive Index of Air: Dependence on Pressure, Temperature and Composition”. Applied Optics, 6(1), January 1967.Google Scholar
- 14.M. Shinya and A. Fournier. “Stochastic Motion — Motion Under the Influence of Wind”. In Proceedings of Eurographics ’92, pages 119–128, September 1992.Google Scholar
- 15.J. Stam. “Stochastic Rendering of Density Fields”. In Proceedings of Graphics Interface ’94, pages 51–58, Banff, Alberta, May 1994.Google Scholar
- 16.J. Stam and E. Fiume. “Turbulent Wind Fields for Gaseous Phenomena”. In Proceedings of SIGGRAPH ’93, pages 369–376. Addison-Wesley Publishing Company, August 1993.Google Scholar