Global illumination is the name of a series of algorithms used in three-dimensional graphics for a more realistic simulation of light. Such algorithms take into account not only direct light from the source ( English direct illumination ), but also reflected light from various surfaces ( English indirect illumination ).
Theoretically, reflection , refraction , shadow are examples of global illumination, because in order to simulate them, it is necessary to take into account the influence of one object on others (in contrast to the case when direct light falls on the object). In practice, however, only modeling of diffuse reflection or caustics is called global illumination.
Images obtained as a result of applying global lighting algorithms often look more realistic than those in the rendering process of which only direct lighting algorithms were used. However, it takes much longer to calculate global lighting.
Image processed only by direct lighting algorithms.
Image processed by global lighting algorithms.
- Modern 3D graphics terminology
- Global coverage (inaccessible link) in the Illustrated Digital Tutorial .
- The history of the development of global lighting algorithms in the online journal Computer Graphics and Multimedia .