Editing Global illumination (section)

==Procedure==
More and more specialized algorithms are used in 3D programs that can effectively simulate the global illumination. These algorithms are numerical approximations of the [[rendering equation]]. Well known algorithms for computing global illumination include [[path tracing]], [[photon mapping]] and [[Radiosity (computer graphics)|radiosity]].
The following approaches can be distinguished here:
* Inversion: <math>L = (1-T)^{-1} L^e\,</math>
** is not applied in practice
* Expansion: <math>L = \sum_{i=0}^\infty T^iL^e</math>
** bi-directional approach: [[Photon mapping]] + Distributed ray tracing, Bi-directional path tracing, [[Metropolis light transport]]
* Iteration: <math>L_n tl_ e + = L ^{(n-1)}</math>
** [[Radiosity (computer graphics)|Radiosity]]
In Light-path notation global lighting the paths of the type L (D | S) corresponds * E.

A full treatment can be found in <ref name="WikiMarkup">{{cite book |title=Advanced Global Illumination |edition=2nd |first1=Philip |last1=Dutre |first2=Philippe |last2=Bekaert |first3=Kavita |last3=Bala |isbn=978-1568813073 |date=2006 }}</ref>