Displacement mapping

Displacement mapping is an alternative computer graphics technique in contrast to <a href="/facts/Bump_mapping/c97rLmK6">bump</a>, <a href="/facts/Normal_mapping/7YmzxkPp">normal</a>, and <a href="/facts/Parallax_mapping/9mztrTcu">parallax</a> <a href="/facts/Texture_mapping/9gDTsuXN">mapping</a>, using a <a href="/facts/Image_texture/tLQx6EP2">texture</a> or <a href="/facts/Heightmap/EwXCqTY7">height map</a> to cause an effect where the actual geometric position of points over the textured surface are displaced, often along the <a href="/facts/Locally/sdBEwIy2">local</a> <a href="/facts/Surface_normal/jhtLIhcu">surface normal</a>, according to the value the texture function evaluates to at each point on the surface. It gives surfaces a sense of depth and detail, permitting in particular self-occlusion, <a href="/facts/Self-shadowing/IkDoPM4K">self-shadowing</a> and silhouettes; on the other hand, it is the most costly of this class of techniques owing to the large amount of additional geometry.
For years, displacement mapping was a peculiarity of high-end rendering systems like <a href="/facts/PhotoRealistic_RenderMan/PPAGoFC0">PhotoRealistic RenderMan</a>, while realtime <a href="/facts/Application_programming_interface/GMlN4vUr">APIs</a>, like <a href="/facts/OpenGL/xQoMWePr">OpenGL</a> and <a href="/facts/DirectX/jyy75wVN">DirectX</a>, were only starting to use this feature. One of the reasons for this is that the original implementation of displacement mapping required an adaptive <a href="/facts/Tessellation_(computer_graphics)/xorfyI4q">tessellation</a> of the surface in order to obtain enough <a href="/facts/Micropolygon/9fG3wK0m">micropolygons</a> whose size matched the size of a pixel on the screen.

Displacement mapping open-in-new

Displacement mapping