Editing Parallax mapping (section)

{{Short description|Texture mapping technique}}
<!-- Deleted image removed: [[Image:ParallaxMapping.jpg|thumb|300px|right|Image:ParallaxMapping.jpg| Example of parallax mapping. The walls are [[Texture (visual arts)|texture]]d with parallax maps. Parallax mapping is usually defined in a .glsl file. Here’s Screenshot taken from one of the base examples of the [[open source]] [[Irrlicht Engine|Irrlicht 3d engine]].]] -->
[[File:Parallax mapping.ogv|thumb|Parallax mapping with shadows]]
'''Parallax mapping''' (also called '''offset mapping''' or '''virtual displacement mapping''') is an enhancement of the [[bump mapping]] or [[normal mapping]] techniques applied to [[Texture mapping|textures]] in 3D [[rendering (computer graphics)|rendering]] applications such as [[video game]]s. To the end user, this means that [[texture mapping|textures]] such as stone walls will have more apparent depth and thus greater realism with less of an influence on the performance of the simulation. Parallax mapping was introduced by Tomomichi Kaneko et al., in 2001.<ref name="Kaneko">Kaneko, T., et al., 2001. [https://www.researchgate.net/profile/Susumu_Tachi/publication/228583097_Detailed_shape_representation_with_parallax_mapping/links/02e7e518259abdc882000000.pdf Detailed Shape Representation with Parallax Mapping] {{Webarchive|url=https://web.archive.org/web/20160601214858/https://www.researchgate.net/profile/Susumu_Tachi/publication/228583097_Detailed_shape_representation_with_parallax_mapping/links/02e7e518259abdc882000000.pdf |date=2016-06-01 }}. In Proceedings of ICAT 2001, pp. 205-208.</ref>

Parallax mapping is essentially a method by which rough or uneven surfaces on a 2D texture can be "pulled out" to take on the appearance of a 3D surface. Technically, this is implemented by displacing the texture coordinates at a point on the rendered [[polygon]] by a function of the view angle in [[tangent space]] (the angle relative to the surface [[Normal (geometry)|normal]]) and the value of the [[height map]] at that point. At steeper view-angles, the texture coordinates are displaced more, giving the illusion of depth due to [[parallax]] effects as the view changes. This effect is commonly used for rendering [[Window|windows]] in order to fake 3D interiors for example.

Parallax mapping, as described by Kaneko et al., is a single step process that does not account for [[Occlusion culling|occlusion]]. Subsequent enhancements have been made to the algorithm incorporating iterative approaches to allow for occlusion and accurate silhouette rendering.<ref name="Tatarchuk">Tatarchuk, N., 2005. [http://ati.amd.com/developer/SIGGRAPH05/Tatarchuk-ParallaxOcclusionMapping-Sketch-print.pdf Practical Dynamic Parallax Occlusion Mapping] {{webarchive|url=https://web.archive.org/web/20090925062036/http://ati.amd.com/developer/SIGGRAPH05/Tatarchuk-ParallaxOcclusionMapping-Sketch-print.pdf |date=2009-09-25 }} Siggraph presentations</ref>