Another familiar caustic is the rainbow.[4][5] Scattering of light by raindrops causes different wavelengths of light to be refracted into arcs of differing radius, producing the bow. Computer graphics[edit] A computer-generated image of a wine glass ray traced with photon mapping to simulate caustics In computer graphics, most modern rendering systems support caustics. Some of them even support volumetric caustics. This is accomplished by raytracing the possible paths of a light beam, accounting for the refraction and reflection. Photon mapping is one implementation of this. Volumetric caustics can also be achieved by volumetric path tracing. Some computer graphic systems work by \are modeled as coming from a light source and bouncing around the environment according to rules. Caustics are formed in the regions where sufficient photons strike a surface causing it to be brighter than the average area in the scene. “Backward ray tracing” works in the reverse manner beginning at the surface and determining if there is a direct path to the light source.[6] Some examples of 3D ray-traced caustics can be found here. The focus of most computer graphics systems is aesthetics rather than physical accuracy. This is especially true when it comes to real-time graphics in computer games[7] where generic pre-calculatedtextures are mostly used instead of physically correct calculations. Caustic engineering[edit] Researchers have found that they can make use of caustics to create a desired image by shaping transparent material in a particular way. A surface of a panel of transparent material (e.g. acrylic glass) can be shaped such that the panel refracts light in a specific way to form the chosen image whenever the panel is held at a particular angle between a light source and a white wall.[8][9]
See also[edit] Wikimedia Commons has media related to Custic (optics). ? ? ? ? Computer graphics portal Focus (optics) Circle of confusion Caustic (mathematics) References[edit] 1. Jump up^ Lynch DK and Livingston W (2001). Color and Light in Nature. Cambridge University Press. ISBN 978-0-521-77504-5. Chapter 3.16 The caustic network, Google books preview 2. ^ Jump up to:a b Weinstein, Lev Albertovich (1969). Open Resonators and Open Waveguides. Boulder, Colorado: The Golem Press. 3. Jump up^ Circle Catacaustic. Wolfram MathWorld. Retrieved 2009-07-17. 4. Jump up^ Rainbow caustics 5. Jump up^ Caustic fringes 6. Jump up^ http://http.developer.nvidia.com/GPUGems/gpugems_ch02.html 7. Jump up^ http://www.dualheights.se/caustics/caustics-water-texturing-using-unity3d.shtml 8. Jump up^ Choreographing light: New algorithm controls light patterns called 'caustics', organizes them into coherent images 9. Jump up^ Philip Ball (February 2013). \217 (2902): 40–43. doi:10.1016/S0262-4079(13)60310-3. ? Born, Max; Wolf, Emil (1999). Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light (7th ed.). Cambridge University Press. ISBN 0-521-64222-1. ? Nye, John (1999). Natural Focusing and Fine Structure of Light: Caustics and Wave Dislocations. CRC Press. ISBN 978-0-7503-0610-2. Further reading[edit] ? Ferraro, Pietro (1996). \34 (9): 572. Bibcode:1996PhTea..34..572F. doi:10.1119/1.2344572. ? Dachsbacher, Carsten; Liktor, Gábor (February 2011). \with adaptive beam tracing\ACM: 47–54.
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