Editing 2.5D (section)

==History==
The first video games that used pseudo-3D were primarily [[arcade game]]s, the earliest known examples dating back to the mid-1970s, when they began using [[microprocessor]]s. In 1975, [[Taito]] released ''[[Tomohiro Nishikado#Interceptor|Interceptor]]'',<ref name="Dreams">{{cite web|title=Tomohiro Nishikado's biography at his company's web site |publisher=Dreams, Inc. |archive-url=https://web.archive.org/web/20090401041713/http://www.dreams-game.com/profile/president.html |archive-date=2009-04-01 |url=http://www.dreams-game.com/profile/president.html |access-date=2011-03-27 |url-status=dead }}</ref> an early [[first-person shooter]] and [[Combat flight simulation game|combat flight simulator]] that involved piloting a [[Fighter aircraft|jet fighter]], using an eight-way [[joystick]] to aim with a crosshair and shoot at enemy aircraft that move in formations of two and increase/decrease in size depending on their distance to the player.<ref name=Interceptor>{{KLOV game|8195|Interceptor}}</ref> In 1976, [[Sega]] released ''[[Fonz (arcade)|Moto-Cross]]'', an early black-and-white [[motorbike]] [[racing video game]], based on the [[motocross]] competition, that was most notable for introducing an early three-dimensional [[Third-person (video games)|third-person]] perspective.<ref name=Moto-Cross>{{KLOV game|12812|Moto-Cross}}</ref> Later that year, [[Gremlin Industries|Sega-Gremlin]] re-branded the game as ''[[Fonz (arcade)|Fonz]]'', as a tie-in for the popular [[sitcom]] ''[[Happy Days]]''.<ref name=Fonz>{{KLOV game|id=12812|name=Fonz}}</ref> Both versions of the game displayed a constantly changing forward-scrolling road and the player's bike in a third-person perspective where objects nearer to the player are larger than those nearer to the horizon, and the aim was to steer the vehicle across the road, racing against the clock, while avoiding any on-coming motorcycles or driving off the road.<ref name=Moto-Cross/><ref name=Fonz/> That same year also saw the release of two arcade games that extended the car [[driving]] subgenre into three dimensions with a [[First person (video games)|first-person]] perspective: Sega's ''Road Race'', which displayed a constantly changing forward-scrolling S-shaped road with two obstacle race cars moving along the road that the player must avoid crashing while racing against the clock,<ref name=Road-Race>{{KLOV game|12733|Road Race}}</ref> and [[Atari]]'s ''[[Night Driver (arcade game)|Night Driver]]'', which presented a series of posts by the edge of the road though there was no view of the road or the player's car. Games using [[vector graphics]] had an advantage in creating pseudo-3D effects. 1979's ''Speed Freak'' recreated the perspective of ''Night Driver'' in greater detail.

In 1979, [[Nintendo]] debuted ''[[Radar Scope]]'', a [[shoot 'em up]] that introduced a three-dimensional third-person perspective to the genre, imitated years later by [[Shooter game|shooters]] such as [[Konami]]'s ''[[Juno First]]'' and [[Activision]]'s ''[[Beamrider]]''.<ref>{{cite web|url=http://www.1up.com/do/feature?pager.offset=1&cId=3181467|archive-url=https://web.archive.org/web/20121017222352/http://www.1up.com/do/feature?pager.offset=1&cId=3181467|url-status=dead|archive-date=17 October 2012|title=Where Were They Then: The First Games of Nintendo, Konami, and More from 1UP.com|date=17 October 2012|access-date=19 March 2018}}</ref> In 1980, Atari's ''[[Battlezone (1980 video game)|Battlezone]]'' was a breakthrough for pseudo-3D gaming, recreating a 3D perspective with unprecedented realism, though the gameplay was still planar. It was followed up that same year by ''[[Red Baron (1980 video game)|Red Baron]]'', which used scaling vector images to create a forward scrolling [[rail shooter]].

[[Sega]]'s arcade shooter ''Space Tactics'', released in 1980, allowed players to take aim using crosshairs and shoot lasers into the screen at enemies coming towards them, creating an early 3D effect.<ref>{{KLOV game|id=9683|name=Space Tactics}}</ref> It was followed by other arcade shooters with a first-person perspective during the early 1980s, including [[Taito]]'s 1981 release ''[[List of Taito games|Space Seeker]]'',<ref>{{KLOV game|id=9682|name=Space Seeker}}</ref> and Sega's ''[[Star Trek (arcade game)|Star Trek]]'' in 1982.<ref>{{KLOV game|9770|Star Trek}}</ref> Sega's ''[[SubRoc-3D]]'' in 1982 also featured a first-person perspective and introduced the use of [[List of stereoscopic video games|stereoscopic 3-D]] through a special eyepiece.<ref>{{KLOV game|9856|SubRoc-3D}}</ref> Sega's ''[[Astron Belt]]'' in 1983 was the first [[laserdisc video game]], using [[full-motion video]] to display the graphics from a first-person perspective.<ref>{{cite web|url=http://www.allgame.com/game.php?id=9550|title=Astron Belt - Overview - allgame|archive-url=https://web.archive.org/web/20141114095114/http://www.allgame.com/game.php?id=9550|archive-date=2014-11-14}}</ref> [[Third-person shooter|Third-person]] rail shooters were also released in arcades at the time, including Sega's ''[[Tac/Scan]]'' in 1982,<ref>{{KLOV game|id=10007|name=Tac/Scan}}</ref> [[Nippon Electric Company|Nippon]]'s ''Ambush'' in 1983,<ref>{{KLOV game|6878|Ambush}}</ref> [[Nihon Bussan|Nichibutsu]]'s ''[[Nihon Bussan#Action role-playing|Tube Panic]]'' in 1983,<ref>{{cite web|url=http://www.allgame.com/game.php?id=32709|title=Tube Panic - Overview - allgame|archive-url=https://web.archive.org/web/20141115105644/http://www.allgame.com/game.php?id=32709|archive-date=2014-11-15}}</ref> and Sega's 1982 release ''[[Buck Rogers: Planet of Zoom]]'',<ref>{{KLOV game|7227|Buck Rogers – Planet Of Zoom}}</ref> notable for its fast pseudo-3D scaling and detailed sprites.<ref name=IGN-Sega/>

In 1981, Sega's ''[[Turbo (video game)|Turbo]]'' was the first racing game to use [[Sprite (computer graphics)|sprite]] scaling with full-colour graphics.<ref name=IGN-Sega>{{cite web|url=http://www.ign.com/articles/2009/04/21/ign-presents-the-history-of-sega|title=IGN Presents the History of SEGA|first=Travis|last=Fahs|date=21 April 2009|website=ign.com|access-date=19 March 2018}}</ref> ''[[Pole Position]]'' by [[Namco]] is one of the first racing games to use the trailing camera effect that is now so familiar {{Citation needed|date=September 2023}}.  In this particular example, the effect was produced by linescroll—the practice of scrolling each line independently in order to warp an image.  In this case, the warping would simulate curves and steering.  To make the road appear to move towards the player, per-line color changes were used, though many console versions opted for [[palette animation]] instead.

''[[Zaxxon]]'', a shooter introduced by Sega in 1982, was the first [[Isometric graphics in video games|game to use isometric]] [[axonometric projection]], from which its name is derived. Though Zaxxon's playing field is semantically 3D, the game has many constraints which classify it as 2.5D: a fixed point of view, scene composition from sprites, and movements such as bullet shots restricted to straight lines along the axes. It was also one of the first video games to display shadows.<ref name=Perron>Bernard Perron & Mark J. P. Wolf (2008), ''Video game theory reader two'', [https://books.google.com/books?id=oe0zNalKkTgC&pg=PA158 p. 158], [[Taylor & Francis]], {{ISBN|0-415-96282-X}}</ref> The following year, Sega released the first pseudo-3D [[Isometric adventure game|isometric platformer]], ''[[Congo Bongo]]''.<ref>{{KLOV game|id=7384|name=Congo Bongo}}</ref> Another early pseudo-3D [[platform game]] released that year was [[Konami]]'s ''[[Antarctic Adventure]]'', where the player controls a penguin in a forward-scrolling third-person perspective while having to jump over pits and obstacles.<ref name=KLOV-Antarctic>{{KLOV game|6890|Antarctic Adventure}}</ref><ref name=allgame-Antarctic>{{cite web|url=http://www.allgame.com/game.php?id=19267|title=Antarctic Adventure - Overview - allgame|archive-url=https://web.archive.org/web/20141114184713/http://www.allgame.com/game.php?id=19267|archive-date=2014-11-14}}</ref><ref name=Moby-Antarctic>{{MobyGames|id=/msx/antarctic-adventure|name=Antarctic Adventure}}</ref> It was one of the earliest pseudo-3D games available on a computer, released for the [[MSX]] in 1983.<ref name=Moby-Antarctic/> That same year, [[Irem]]'s ''[[Moon Patrol]]'' was a [[Side-scrolling video game|side-scrolling]] [[Run and gun (video game)|run & gun]] platform-shooter that introduced the use of layered [[parallax scrolling]] to give a pseudo-3D effect.<ref name="parallax">{{cite web|url=http://www.gamesradar.com/f/gamings-most-important-evolutions/a-20101008102331322035/p-3 |archive-url=https://archive.today/20110615221817/http://www.gamesradar.com/f/gamings-most-important-evolutions/a-20101008102331322035/p-3 |archive-date=2011-06-15 |title=Gaming's most important evolutions |publisher=GamesRadar |url-status=dead }}</ref> In 1985, ''[[Space Harrier]]'' introduced Sega's "[[Sega Super Scaler|Super Scaler]]" technology that allowed pseudo-3D [[Sprite (computer graphics)#Move to 3D|sprite-scaling]] at high [[frame rate]]s,<ref name="autogenerated1">{{cite web|url=http://www.ign.com/articles/2009/04/21/ign-presents-the-history-of-sega?page=3|title=IGN Presents the History of SEGA|date=21 April 2009|website=ign.com|access-date=19 March 2018}}</ref> with the ability to scale 32,000 [[Sprite (computer graphics)|sprites]] and fill a moving landscape with them.<ref>Bernard Perron & Mark J. P. Wolf (2008), ''Video game theory reader two'', p. 157, [[Taylor & Francis]], {{ISBN|0-415-96282-X}}</ref>

The first original home [[console game]] to use pseudo-3D, and also the first to use multiple camera angles mirrored on television sports broadcasts, was ''[[Intellivision World Series Baseball]]'' (1983) by [[Don Daglow]] and [[Eddie Dombrower]], published by [[Mattel]]. Its television sports style of display was later adopted by 3D [[sports game]]s and is now used by virtually all major team sports titles. In 1984, Sega ported several pseudo-3D arcade games to the [[Sega SG-1000]] console, including a smooth conversion of the third-person pseudo-3D rail shooter ''Buck Rogers: Planet of Zoom''.<ref name="autogenerated1"/>

By 1989, 2.5D representations were surfaces drawn with depth cues and a part of graphic libraries like GINO.<ref name="Raper">Raper, Jonathan. "The 3-dimensional geoscientific mapping and modeling system: a conceptual design." In Three dimensional applications in Geographic Information Systems, edited by Jonathan F. Raper, 11–19. Philadelphia: Taylor and Francis Inc., 19.</ref> 2.5D was also used in terrain modeling with software packages such as ISM from Dynamic Graphics, GEOPAK from Uniras and the Intergraph DTM system.<ref name="Raper "/> 2.5D surface techniques gained popularity within the geography community because of its ability to visualize the normal thickness to area ratio used in many geographic models; this ratio was very small and reflected the thinness of the object in relation to its width, which made it the object realistic in a specific plane.<ref name="Raper "/> These representations were axiomatic in that the entire subsurface domain was not used or the entire domain could not be reconstructed; therefore, it used only a surface and a surface is one aspect not the full 3D identity.<ref name="Raper "/>

The specific term "two-and-a-half-D" was used as early as 1994 by Warren Spector in an interview in the North American premiere issue of [[PC Gamer]] magazine. At the time, the term was understood to refer specifically to first-person shooters like [[Wolfenstein 3D]] and [[Doom (1993 video game)|Doom]], to distinguish them from [[System Shock]]'s "true" 3D engine.

With the advent of consoles and [[computer system]]s that were able to handle several thousand [[polygon]]s (the most basic element of ''[[3D computer graphics]]'') per second and the usage of 3D specialized [[graphics processing unit]]s, pseudo-3D became obsolete. But even today, there are computer systems in production, such as cellphones, which are often not powerful enough to display ''true'' 3D graphics, and therefore use pseudo-3D for that purpose. Many games from the 1980s' ''pseudo-3D arcade era'' and ''16-bit console era'' are ported to these systems, giving the manufacturers the possibility to earn revenues from games that are several decades old.

[[File:Geabios alps.gif|thumb|Fly through the [[Trenta (valley)|Trenta Valley]]]]
The resurgence of 2.5D or visual analysis, in natural and earth science, has increased the role of computer systems in the creation of spatial information in mapping.<ref name="MacEachren "/> GVIS has made real the search for unknowns, real-time interaction with spatial data, and control over map display and has paid particular attention to three-dimensional representations.<ref name="MacEachren "/> Efforts in GVIS have attempted to expand higher dimensions and make them more visible; most efforts have focused on "tricking" vision into seeing three dimensions in a 2D plane.<ref name="MacEachren "/> Much like 2.5D displays where the surface of a three-dimensional object is represented but locations within the solid are distorted or not accessible.<ref name="MacEachren "/>