Antiportal
Encyclopedia
In computer-generated imagery
and real-time 3D computer graphics
, 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 related to portals, and are the inverse.
An antiportal (or occluder) works by defining a plane or volume
which can never be seen through, normally by placing it within an opaque
object. The renderer uses this to quickly calculate which objects/faces/verticies lie behind the antiportal, and so are out of line of sight, so do not need to be rendered.
Many computer games
and 3D graphics programs use this technique for speed rendering. Unreal Tournament 2004
, among many other games, uses this technique.
Computer-generated imagery
Computer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
and real-time 3D computer graphics
3D computer graphics
3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
, 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 related to portals, and are the inverse.
An antiportal (or occluder) works by defining a plane or volume
Volume
Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
which can never be seen through, normally by placing it within an opaque
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc...
object. The renderer uses this to quickly calculate which objects/faces/verticies lie behind the antiportal, and so are out of line of sight, so do not need to be rendered.
Many computer games
Computer Games
"Computer Games" is a single by New Zealand group, Mi-Sex released in 1979 in Australia and New Zealand and in 1981 throughout Europe. It was the single that launched the band, and was hugely popular, particularly in Australia and New Zealand...
and 3D graphics programs use this technique for speed rendering. Unreal Tournament 2004
Unreal Tournament 2004
Unreal Tournament 2004, also known as UT2K4 and UT2004, is a futuristic first-person shooter computer game developed by Epic Games and Digital Extremes...
, among many other games, uses this technique.