Main menu Main menu move to sidebar hide Navigation Main page Contents Current events Random article About Wikipedia Contact us Contribute Help Learn to edit Community portal Recent changes Upload file Special pages Search Search Appearance Donate Create account Log in Personal tools Donate Create account Log in Contents move to sidebar hide (Top) 1 See also 2 References Toggle the table of contents Spherical harmonic lighting Add languages Add links Article Talk English Read Edit View history Tools Tools move to sidebar hide Actions Read Edit View history General What links here Related changes Upload file Permanent link Page information Cite this page Get shortened URL Print/export Download as PDF Printable version In other projects Wikidata item Appearance move to sidebar hide From Wikipedia, the free encyclopedia Real-time rendering technique This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed. Find sources:   "Spherical harmonic lighting"  –  news   · newspapers   · books   · scholar   · JSTOR ( October 2014 ) ( Learn how and when to remove this message ) Spherical harmonic (SH) lighting is a family of real-time rendering techniques that can produce highly realistic shading and shadowing with comparatively little overhead. All SH lighting techniques involve replacing parts of standard lighting equations with spherical functions that have been projected into frequency space using the spherical harmonics as a basis. To take a simple example, a cube map used for environment mapping might be reduced to just nine SH coefficients if preserving high-frequency detail is not a concern. [ 1 ] More intriguing techniques use SH to encode multiple functions—usually the global lighting environment and a per-vertex radiance transfer function. The generalized lighting equation involves, among other things, integrating the product of the incoming radiance and the BRDF over a sphere—something that is far too expensive for real-time rendering. But if the two functions are projected into SH coefficients, the integral of their product over the sphere is just the dot product of the two SH coefficient vectors. Generating the per-vertex transfer functions and projecting them to SH space is still an expensive process, but evaluating them is almost trivial. More to the point, they can be evaluated correctly even if the lighting environment changes in intensity or orientation. Even the most complex ray-traced radiosity algorithm can be rendered in real-time with dynamically changing lighting. SH lighting using preprocessed coefficients produces results that are beautiful but limited. Typically the lighting can change, or the lit mesh can be rotated, but the mesh can't be translated or deformed without requiring a new set of per-vertex coefficients. More recent techniques split the lighting equation into more parts and introduce techniques for updating SH components in real time or learn a transfer function which maps from shape deformations to updated per-vertex coefficients. [ 2 ] Representing scene illumination using SH is increasingly popular in the field of neural rendering as the illumination in a scene can be predicted and manipulated using deep neural networks. See also [ edit ] Precomputed Radiance Transfer Radiosity Comprehensive Overview References [ edit ] ^ An Efficient Representation for Irradiance Environment Maps ^ Schneider, Andreas; Schonborn, Sandro; Egger, Bernhard; Frobeen, Lavrenti; Vetter, Thomas (2017). "Efficient Global Illumination for Morphable Models" . 2017 IEEE International Conference on Computer Vision (ICCV) (PDF) . pp.  3885– 3893. doi : 10.1109/ICCV.2017.417 . ISBN   978-1-5386-1032-9 . This computer graphics –related article is a stub . You can help Wikipedia by adding missing information . v t e Retrieved from " https://en.wikipedia.org/w/index.php?title=Spherical_harmonic_lighting&oldid=1253909110 " Categories : Shading Computer graphics stubs Hidden categories: Use American English from March 2019 All Wikipedia articles written in American English Articles with short description Short description matches Wikidata Articles needing additional references from October 2014 All articles needing additional references All stub articles This page was last edited on 28 October 2024, at 14:34  (UTC) . Text is available under the Creative Commons Attribution-ShareAlike 4.0 License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy . Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. , a non-profit organization. Privacy policy About Wikipedia Disclaimers Contact Wikipedia Legal & safety contacts Code of Conduct Developers Statistics Cookie statement Mobile view Search Search Toggle the table of contents Spherical harmonic lighting Add languages Add topic