Editing Texture mapping (section)

===Multitexturing===
Multitexturing is the use of more than one texture at a time on a polygon.<ref>Blythe, David. ''[https://web.archive.org/web/20200228185024/https://pdfs.semanticscholar.org/fc76/bb3649978a1939d9bd9d9d3769f47ebfc6c1.pdf Advanced Graphics Programming Techniques Using OpenGL].'' Siggraph 1999. ([[PDF]]) (see: [https://web.archive.org/web/20120108033621/http://www.opengl.org/resources/code/samples/sig99/advanced99/notes/node60.html Multitexture])</ref> For instance, a [[Lightmap|light map]] texture may be used to light a surface as an alternative to recalculating that lighting every time the surface is rendered. '''Microtextures''' or '''detail textures''' are used to add higher frequency details, and '''dirt maps''' may add weathering and variation; this can greatly reduce the apparent periodicity of repeating textures. Modern graphics may use more than 10 layers, which are combined using [[shaders]], for greater fidelity. Another multitexture technique is [[bump mapping]], which allows a texture to directly control the facing direction of a surface for the purposes of its lighting calculations; it can give a very good appearance of a complex surface (such as tree bark or rough concrete) that takes on lighting detail in addition to the usual detailed coloring. Bump mapping has become popular in recent video games, as graphics hardware has become powerful enough to accommodate it in real-time.<ref>[https://web.archive.org/web/20150914190914/http://web4.cs.ucl.ac.uk/staff/j.kautz/publications/rtbumpmapHWWS01.pdf Real-Time Bump Map Synthesis], Jan Kautz<sup>1</sup>, Wolfgang Heidrichy<sup>2</sup> and Hans-Peter Seidel<sup>1</sup>, (<sup>1</sup>Max-Planck-Institut für Informatik, <sup>2</sup>University of British Columbia)</ref>