In computer-generated imagery and real-time

3D computer graphics 3D computer graphics, or “3D graphics,” sometimes called CGI, 3D-CGI or three-dimensional computer graphics are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for t ...

, antiportal rendering is a way to reduce overdraw (the rendering of detail which will not be in the final image), and in this way to optimize draw speed. Antiportals are the inverse of

portal Portal often refers to: * Portal (architecture), an opening in a wall of a building, gate or fortification, or the extremities (ends) of a tunnel Portal may also refer to: Arts and entertainment Gaming * ''Portal'' (series), two video games ...

s. An antiportal (or occluder) works by defining a

plane Plane(s) most often refers to: * Aero- or airplane, a powered, fixed-wing aircraft * Plane (geometry), a flat, 2-dimensional surface Plane or planes may also refer to: Biology * Plane (tree) or ''Platanus'', wetland native plant * ''Planes' ...

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...

which can ''never'' be seen through, normally by placing it within an

opaque Opacity or opaque may refer to: * Impediments to (especially, visible) light: ** Opacities, absorption coefficients ** Opacity (optics), property or degree of blocking the transmission of light * Metaphors derived from literal optics: ** In lingu ...

object. The renderer uses this to quickly calculate which objects/faces/vertices lie behind the antiportal, and so are out of line of sight, so do not need to be rendered. Many

video game Video games, also known as computer games, are electronic games that involves interaction with a user interface or input device such as a joystick, controller, keyboard, or motion sensing device to generate visual feedback. This fee ...

s and 3D graphics programs use this technique for speed rendering. ''

Unreal Tournament 2004 ''Unreal Tournament 2004'' is a first-person arena shooter video game developed by Epic Games and Digital Extremes. Part of the ''Unreal'' franchise, it is the third game in the '' Unreal Tournament'' series and the sequel to '' Unreal Tournam ...

'', among many other games, uses this technique.

References

Computer graphics Unreal (video game series) {{Compu-graphics-stub

See also

References