Editing Game engine (section)

==History==
[[File:Quake - family tree 2 Simplified.svg|thumb|300px|Some game engines experience an evolution over time and develop a family tree, like for instance [[id software|id's]] [[Quake engine]] which resulted in the [[id Tech]] family.]]
Before game engines, games were typically written as singular entities: a game for the [[Atari 2600]], for example, had to be designed from the bottom up to make optimal use of the display hardware—this core display routine is today called the [[kernel (operating system)|kernel]] by developers of games for older systems. Other platforms had more leeway, but even when the display was not a concern, memory constraints usually sabotaged attempts to create the data-heavy design that an engine needs. Even on more accommodating platforms, very little could be reused between games. The rapid advance of [[arcade game|arcade]] [[arcade system board|hardware]]—which was the leading edge of the market at the time—meant that most of the code would have to be thrown out afterwards anyway, as later generations of games would use completely different game designs that took advantage of extra resources. Thus most game designs through the 1980s were designed through a hard-coded rule set with a small number of levels and graphics data. Since the [[golden age of arcade video games]], it became common for video game companies to develop in-house game engines for use with first-party software.

A notable example of an in-house game engine on [[home video game console|home consoles]] in the mid-1980s was the smooth [[side-scrolling]] engine developed by [[Shigeru Miyamoto]]'s team at [[Nintendo]] for the [[Nintendo Entertainment System]] (NES). The engine they had developed for the side-scrolling [[racing game]] ''[[Excitebike]]'' (1984) was later employed for the scrolling [[platformer]] ''[[Super Mario Bros.]]'' (1985). This had the effect of allowing [[Mario]] to smoothly accelerate from a walk to a run, rather than move at a constant speed like in earlier platformers.<ref>{{cite book |last1=Williams |first1=Andrew |title=History of Digital Games: Developments in Art, Design and Interaction |date=16 March 2017 |publisher=[[CRC Press]] |isbn=978-1-317-50381-1 |pages=152–4}}</ref>

While third-party game engines were not common up until the rise of [[3D computer graphics]] in the 1990s, there were several 2D [[game creation system]]s produced in the 1980s for [[independent video game development]]. These include ''[[Pinball Construction Set]]'' (1983), [[ASCII (company)|ASCII]]'s ''War Game Construction Kit'' (1983),<ref>{{cite web|title=War Game Construction Kit|url=http://retropc.net/fm-7/museum/softhouse/ascii/000701300.html|work=[[:ja:Oh!FM|Oh!FM]]|access-date=3 September 2012|archive-url=https://web.archive.org/web/20130728111753/http://retropc.net/fm-7/museum/softhouse/ascii/000701300.html|archive-date=28 July 2013}} [https://translate.google.com/translate?hl=en&sl=ja&tl=en&u=http%3A%2F%2Fretropc.net%2Ffm-7%2Fmuseum%2Fsofthouse%2Fascii%2F000701300.html Alt URL]</ref> ''[[Thunder Force (series)|Thunder Force Construction]]'' (1984),<ref>{{cite web|title=Thunder Force Construction|url=http://retropc.net/fm-7/museum/softhouse/tecnosoft/330602301.html|work=[[:jp:Oh!FM|Oh!FM]]|access-date=1 September 2012|archive-url=https://web.archive.org/web/20130728113345/http://retropc.net/fm-7/museum/softhouse/tecnosoft/330602301.html|archive-date=28 July 2013}} [https://translate.google.com/translate?sl=ja&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fretropc.net%2Ffm-7%2Fmuseum%2Fsofthouse%2Ftecnosoft%2F330602301.html Alt URL]</ref> ''[[Adventure Construction Set]]'' (1984), [[Garry Kitchen's GameMaker]] (1985), ''[[Wargame Construction Set]]'' (1986), ''[[Shoot-'Em-Up Construction Kit]]'' (1987), ''[[Arcade Game Construction Kit]]'' (1988), and most popularly ASCII's ''[[RPG Maker]]'' engines from 1998 onward. Klik & Play (1994) is another legacy offering that is still available.<ref name="produsase japan">{{cite journal | last= Fiadotau | first = Mikhail | title = Dezaemon, RPG Maker, NScripter: Exploring and classifying game 'produsage' in 1990s Japan | journal = Journal of Gaming & Virtual Worlds | volume = 11 | issue = 3 | pages=215–230 | date = 2019 | doi = 10.1386/jgvw.11.3.215_1 | s2cid = 213694676}}</ref>

The term "game engine" arose in the mid-1990s, especially in connection with 3D games such as [[first-person shooter]]s with a [[first-person shooter engine]]. Epic games, founded by developer Tim Sweeney, debuted Unreal Engine in the year 1998.<ref>{{Cite web|last=Weinberger|first=Matt|title=The CEO behind 'Fortnite' says it's 'evolving beyond being a game' and explains the company's ambitious vision|url=https://www.businessinsider.com/epic-games-ceo-tim-sweeney-fortnite-unreal-engine-2019-3|access-date=2022-02-17|website=Business Insider|language=en-US}}</ref>

Such was the popularity of [[Id Software]]'s ''[[Doom (1993 video game)|Doom]]'' and ''[[Quake (series)|Quake]]'' games that, rather than work from scratch, other developers licensed the core portions of the software and designed their own graphics, characters, weapons and [[level (computer and video games)|level]]s—the "game content" or "game assets". Separation of game-specific rules and data from basic concepts like [[collision detection]] and game entity meant that teams could grow and specialize.<ref name="produsase japan" />

Later games, such as [[id Software]]'s ''[[Quake III Arena]]'' and [[Epic Games]]'s 1998 ''[[Unreal (1998 video game)|Unreal]]'' were designed with this approach in mind, with the engine and content developed separately. The practice of licensing such technology has proved to be a useful auxiliary revenue stream for some game developers, as one license for a high-end commercial game engine can range from $10,000 to millions of dollars, and the number of licensees can reach several dozen companies, as seen with the [[Unreal Engine]]. At the very least, reusable engines make developing game sequels faster and easier, which is a valuable advantage in the competitive video game industry. While there was a strong rivalry between Epic and id around the year 2000, since then Epic's Unreal Engine has been far more popular than [[id Tech 4]] and its successor [[id Tech 5]].<ref>{{cite web|last=Bramwell |first=Tom |url=http://www.eurogamer.net/articles/id-tech-5-interview |title=id Tech 5 Interview • Page 1 • Interviews • |publisher=Eurogamer.net |date=2007-08-09 |access-date=2013-11-24}}</ref><!--Actually John Carmack of id just wasn't at all interested in licensing the engine and then spend time giving support to the licensees, because he wanted to write the next engine. -->

Modern game engines are some of the most complex applications written, often featuring dozens of finely tuned systems interacting to ensure a precisely controlled user experience. The continued evolution of game engines has created a strong separation between rendering, scripting, artwork, and [[level design]]. It is now common, for example, for a typical game development team to have several times as many artists as actual programmers.<ref>{{cite web |url=http://web.cs.wpi.edu/~id111x/c05/slides/intro.ppt |title=Game Development Team Composition Study - Changes over time. |access-date=2011-01-17}}</ref>

First-person shooter games remain the predominant users of third-party game engines, but they are now also being used in other [[video game genres|genres]]. For example, the [[role-playing video game]] ''[[The Elder Scrolls III: Morrowind]]'' and the [[MMORPG]] ''[[Dark Age of Camelot]]'' are based on the [[Gamebryo]] engine, and the MMORPG ''[[Lineage II]]'' is based on the Unreal Engine. Game engines are used for games originally developed for home consoles as well; for example, the [[RenderWare]] engine is used in the ''[[Grand Theft Auto]]'' and ''[[Burnout (game)|Burnout]]'' franchises.

[[Thread (computer science)|Threading]] is taking on more importance due to modern multi-core systems (e.g. [[Cell (microprocessor)|Cell]]) and increased demands in realism. Typical threads involve rendering, streaming, audio, and physics. Racing games have typically been at the forefront of threading with the physics engine running in a separate thread long before other core subsystems were moved, partly because rendering and related tasks need updating at only 30–60&nbsp;Hz. For example, on PlayStation 3, physics ran in ''[[Need For Speed]]'' at 100&nbsp;Hz versus ''[[Forza Motorsport 2]]'' at 360&nbsp;Hz.

Although the term was first used in the 1990s, there are a few earlier systems in the 1980s that are also considered to be game engines, such as Sierra's [[Adventure Game Interpreter]] (AGI) and SCI systems, LucasArts' [[SCUMM]] system and [[Incentive Software]]'s [[Freescape engine]] (in 1986<ref>{{cite web|url=https://www.uvlist.net/groups/info/freescapeengine |title=Freescape Engine|publisher=Universal Videogame List |access-date=2020-05-16}}</ref>). Unlike most modern game engines, these game engines were never used in any third-party products (except for the SCUMM system which was licensed to and used by [[Humongous Entertainment]]).

As game engine technology matures and becomes more user-friendly, the application of game engines has broadened in scope. They are now being used for [[serious game]]s: visualization, training, medical, and [[military simulation]] applications, with the [[CryEngine]] being one example.<ref>{{cite web |url=http://www.gazette.net/stories/083107/businew11739_32356.shtml |title=Video Games Starting to Get Serious |publisher=Gazette.net |date=2007-08-31 |access-date=2011-01-17 |archive-url=https://web.archive.org/web/20081203174009/http://www.gazette.net/stories/083107/businew11739_32356.shtml |archive-date=2008-12-03 |url-status=dead}}</ref> To facilitate this accessibility, new hardware platforms are now being targeted by game engines, including [[mobile phone]]s (e.g. [[Android (operating system)|Android]] phones, [[iPhone]]) and [[web browser]]s (e.g. [[WebGL]], [[Adobe Shockwave|Shockwave]], [[Adobe Flash|Flash]], [[Trinigy]]'s WebVision, [[Silverlight]], [[Unity Web Player]], [[O3D]] and pure [[DHTML]]).<ref>{{cite web |url=http://www.m-trends.org/2008/01/mobile-and-wireless-trends-for-2008.html |title=Gaming: Mobile and Wireless Trends for 2008 |publisher=M-trends.org |access-date=2011-01-17 |url-status=dead |archive-url=https://web.archive.org/web/20110108073502/http://www.m-trends.org/2008/01/mobile-and-wireless-trends-for-2008.html |archive-date=2011-01-08}}</ref>

Additionally, more game engines are being built upon [[high-level programming language|higher level languages]] such as [[Java (programming language)|Java]] and [[C Sharp (programming language)|C#]]/[[.NET Framework|.NET]] (e.g. [[Torque Game Engine|TorqueX]], and [[Visual3D.NET]]), Python ([[Panda3D]]), or [[Lua (programming language)|Lua Script]] (Leadwerks). As most 3D rich games are now mostly [[GPU]]-limited (i.e. limited by the power of the graphics card), the potential slowdown due to translation overheads of higher level languages becomes negligible, while the productivity gains offered by these languages work to the game engine developers' benefit.<ref>{{cite book|url=https://books.google.com/books?id=-vifhqAi0SEC&q=gpu-limited+games&pg=PA338 |title=3D Game Engine Programming (book) |isbn=9781592003518 |access-date=2011-01-17|last1=Zerbst |first1=Stefan |last2=Düvel |first2=Oliver |year=2004|publisher=Premier Press }}</ref> These recent trends are being propelled by companies such as [[Microsoft]] to support [[independent game development|indie]] game development. Microsoft developed [[Microsoft XNA|XNA]] as the SDK of choice for all video games released on Xbox and related products. This includes the Xbox Live Indie Games<ref>{{cite web|url=http://www.xboxlivecommunitygames.org/ |title=xboxlivecommunitygames.org |publisher=xboxlivecommunitygames.org |access-date=2013-11-24}}</ref> channel designed specifically for smaller developers who do not have the extensive resources necessary to box games for sale on retail shelves. It is becoming easier and cheaper than ever to develop game engines for platforms that support [[managed code|managed]] frameworks.<ref name=":0">{{cite web | title = Microsoft to Enable User-Created XBox 360 Games | url=http://www.gamasutra.com/php-bin/news_index.php?story=10458 | archive-url=https://archive.today/20130102181027/http://www.gamasutra.com/php-bin/news_index.php?story=10458 | url-status=dead | archive-date=January 2, 2013 | access-date=2017-05-05}}</ref>