View source for Unreal Engine 4

{{Infobox software
| name                   = Unreal Engine
| logo                   = UE Logo Black Centered.svg
| logo size              = 100px
| screenshot             = Unreal Engine 4 screenshot.png
| caption                = Unreal Engine 4.20 screenshot
| author                 = [[Tim Sweeney (game developer)|Tim Sweeney]]
| developer              = [[Epic Games]]
| released               = {{Start date and age|1998|5|}}
| latest release version = <!-- Used by Template:Latest stable software release/Unreal Engine -->
| latest preview version = <!-- Used by Template:Latest preview software release/Unreal Engine -->
| repo                   = 
| programming language   = [[C++]]
| operating system       = 
| platform               = 
| language               = 
| genre                  = [[Game engine]]
| license                = [[Source-available]] [[commercial software]] with [[Royalty payment|royalty]] model for commercial use<ref>{{cite web|accessdate=2018-08-26|title=Unreal Engine End User License Agreement|url=https://www.unrealengine.com/en-US/eula|website=Unreal Engine}}</ref>
| alexa                  = {{Alexa|up|1,973|{{As of|2019|06|10|df=US}}|inline=y}}<ref>{{Cite web |url=https://www.alexa.com/siteinfo/unrealengine.com |title=Unrealengine.com Competitive Analysis, Marketing Mix and Traffic |website=[[Alexa Internet]] |access-date=June 10, 2019}}</ref>
| website                = {{URL|http://www.unrealengine.com|unrealengine.com}}
}}

The '''Unreal Engine''' is a [[game engine]] developed by [[Epic Games]], first showcased in the 1998 [[first-person shooter]] [[Video game|game]] ''[[Unreal (1998 video game)|Unreal]]''. Although initially developed for first-person shooters, it has been successfully used in a variety of other genres, including [[Stealth game|stealth]], [[fighting game]]s, [[Massively multiplayer online role-playing game|MMORPG]]s, and other [[Role-playing video game|RPG]]s. With its code written in [[C++]], the Unreal Engine features a high degree of portability and is a tool used by many [[Video game developer|game developers]] today, with it being [[Source-available software|source-available]]. The most recent version is Unreal Engine 4, which was released in 2014.

==History==

===Unreal Engine 4===
[[File:UE4Arch.com - Viennese apartment.webm|thumbtime=38|left|thumb|300px|Interactive architectural visualization made in UE4.]]

In August 2005, [[Mark Rein (software executive)|Mark Rein]], the vice-president of Epic Games, revealed that Unreal Engine 4 had been in development since 2003.<ref>{{cite web|title=Rein: "We've been working on Unreal Engine 4 for two years" |url=http://www.computerandvideogames.com/123639/rein-weve-been-working-on-unreal-engine-4-for-two-years/ |work=[[Computer and Video Games]] |publisher=Future Publishing Limited |last=Houlihan |first=John |accessdate=August 19, 2005 |date=August 18, 2005 |deadurl=yes |archiveurl=https://web.archive.org/web/20140110101539/http://www.computerandvideogames.com/123639/rein-weve-been-working-on-unreal-engine-4-for-two-years/ |archivedate=January 10, 2014 }}</ref> Until 2008, development was "basically" done by Sweeney.<ref>{{cite web|title=Tim Sweeney, Part 3: Unreal Engine 4.0 aims at next-gen console war |url=http://www.tgdaily.com/business-and-law-features/36436-tim-sweeney-part-3-unreal-engine-40-aims-at-next-gen-console-war |work=TG Daily |last=Valich |first=Theo |publisher=Tigervision Media |accessdate=March 13, 2008 |date=March 12, 2008 |deadurl=no |archiveurl=https://web.archive.org/web/20091212002845/http://www.tgdaily.com/business-and-law-features/36436-tim-sweeney-part-3-unreal-engine-40-aims-at-next-gen-console-war |archivedate=December 12, 2009 }}</ref> The engine targets the [[History of video game consoles (eighth generation)|eighth generation]] of consoles, PCs, and [[Tegra K1]]-based devices running [[Android (operating system)|Android]] announced in January 2014 at [[Consumer Electronics Show|CES]].

In February 2012, Rein said "people are going to be shocked later this year when they see Unreal Engine 4".<ref>{{cite web |title=Epic Revealing Unreal Engine 4 Later This Year |work=Tom's Hardware |date=February 11, 2012 |last=Parrish |first=Kevin |url=http://www.tomshardware.com/news/Epic-Games-Unreal-Engine-4-UE4-Mark-Rein-DICE-2012,14682.html |accessdate=March 1, 2012}}</ref> Unreal Engine 4 was unveiled to limited attendees at the 2012 [[Game Developers Conference]],<ref>{{cite news|title=Unreal Engine 4 Behind Closed Doors at GDC |work=Wired |last=Shaw |first=Patrick |url=https://www.wired.com/gamelife/2012/02/unreal-engine-4-gdc/ |accessdate=March 6, 2012 |date=February 27, 2012 |deadurl=no |archiveurl=https://web.archive.org/web/20120301192419/http://www.wired.com/gamelife/2012/02/unreal-engine-4-gdc |archivedate=March 1, 2012 }}</ref> and video of the engine being demonstrated by technical artist Alan "Talisman" Willard was released to the public in June 7, 2012 via [[GameTrailers TV with Geoff Keighley|GameTrailers TV]].<ref>{{Cite web |url=https://www.youtube.com/watch?v=MOvfn1p92_8 |title=Unreal Engine 4 - GT.TV Exclusive Development Walkthrough |date=June 7, 2012 |publisher=[[GameTrailers TV with Geoff Keighley|GameTrailers TV]] | via =[[YouTube]] |access-date=August 22, 2018}}</ref>

One of the major features planned for UE4 was real-time global illumination using [[Cone tracing|voxel cone tracing]], eliminating pre-computed lighting.<ref name="nvidia"/> However, this feature has been replaced with a similar but less computationally-expensive algorithm prior to release for all platforms including the PC due to performance concerns.<ref>{{Cite web |url=https://www.dsogaming.com/news/epic-games-tim-sweeney-explains-lack-of-svogi-in-unreal-engine-4/ |title=Epic Games’ Tim Sweeney Explains Lack Of ‘SVOGI’ In Unreal Engine 4 |last=Papadopoulos |first=John |date=April 20, 2013 |website=Dark Side of Gaming |access-date=February 14, 2018}}</ref> UE4 also includes new developer features to reduce iteration time, and allows updating of [[C++]] code while the engine is running. The new "Blueprints" visual scripting system (a successor to UE3's "Kismet"<ref name="rps"/>) allows for rapid development of game logic without using C++, and includes live debugging.<ref>{{cite web|url=https://www.forbes.com/sites/jasonevangelho/2014/05/22/why-is-epic-games-promoting-unreal-engine-4-with-a-flappy-bird-clone/ |title=Why Is Epic Games Promoting Unreal Engine 4 With A 'Flappy Bird' Clone? |work=[[Forbes]] |publisher=Forbes, Inc. |date=May 22, 2014 |accessdate=February 8, 2015 |first=Jason |last=Evangelho |deadurl=no |archiveurl=https://web.archive.org/web/20150208145513/http://www.forbes.com/sites/jasonevangelho/2014/05/22/why-is-epic-games-promoting-unreal-engine-4-with-a-flappy-bird-clone/ |archivedate=February 8, 2015 }}</ref><ref>{{cite magazine|url=https://www.forbes.com/sites/davidthier/2012/06/29/epics-tim-sweeney-on-how-unreal-engine-4-will-change-the-way-games-are-made-and-why-you-care/ |title=Epic's Tim Sweeney on How Unreal Engine 4 Will Change The Way Games Are Made, and Why You Care |magazine=[[Forbes]] |date=June 29, 2012 |accessdate=October 4, 2014 |first=Dave |last=Thier |deadurl=no |archiveurl=https://web.archive.org/web/20141006105926/http://www.forbes.com/sites/davidthier/2012/06/29/epics-tim-sweeney-on-how-unreal-engine-4-will-change-the-way-games-are-made-and-why-you-care/ |archivedate=October 6, 2014 }}</ref> The result is reduced iteration time, and less of a divide between technical artists, designers, and programmers.<ref name=kotakuUE4>{{cite web|last=Totilo |first=Stephen |title=How Unreal Engine 4 Will Change The Next Games You Play |url=http://kotaku.com/5916859/how-unreal-engine-4-will-change-the-next-games-you-play |publisher=Kotaku |date=June 8, 2012 |deadurl=no |archiveurl=https://web.archive.org/web/20121024091239/http://kotaku.com/5916859/how-unreal-engine-4-will-change-the-next-games-you-play |archivedate=October 24, 2012 }}</ref>

{{quotation|I could say: 'I'm going to convert this pillar into a blueprint [in the Engine] and add some sort of trap to it.' It means I can really go in and start enhancing my world with interaction that just would not have been possible without a technical artist, a designer and a programmer and now any one of those three can do all of it, provided they have the assets handy. The fact that I can just go in and say, 'If you're within X distance of this thing, start to glow and take my distance to it, normalize it zero to one and then just lerp [oscillate] between two different brightness values, so as I reach for something it gets hot'...that would have been something do-able but very difficult for anybody except a gameplay programmer. And he wouldn't have known how to set up the assets, but now any one of the three could do it.|Willard, ''[[Kotaku]]'', 2012<ref name="kotakuUE4" />}}

On March 19, 2014, at the [[Game Developers Conference]] (GDC), Epic Games released Unreal Engine 4 through a new licensing model. For a monthly subscription at {{USD|19}}, developers were given access to the full version of the engine, including the [[C++]] source code, which could be downloaded via [[GitHub]]. Any released product was charged with a 5% royalty of gross revenues.<ref>{{Cite web |url=https://arstechnica.com/gaming/2014/03/unreal-engine-4-now-available-as-19month-subscription-with-5-royalty/ |title=Unreal Engine 4 now available as $19/month subscription with 5% royalty |last=Orland |first=Kyle |date=March 19, 2014 |website=[[Ars Technica]] |access-date=August 8, 2018}}</ref> The first game released using Unreal Engine 4 was ''[[Daylight (video game)|Daylight]]'', developed with early access to the engine<ref>{{Cite web |url=https://www.unrealengine.com/en-US/blog/zombie-studios-licenses-unreal-engine-4 |title=Zombie Studios Licenses Unreal Engine 4 |date=2012-12-18 |website=unrealengine.com |language=en-US |access-date=2019-01-23}}</ref> and released on April 29, 2014.<ref>{{Cite web |url=https://www.pcgamesn.com/daylight/making-it-in-unreal-how-daylight-survived-public-pressure-and-became-the-very-first-ue4-game |title=Making it in Unreal: How Daylight survived public pressure and became the very first UE4 game |date=2014-11-24 |website=PCGamesN |language=en-GB |access-date=2019-01-22}}</ref>

On September 4, 2014, Epic released Unreal Engine 4 to schools and universities for free, including personal copies for students enrolled in accredited video game development, computer science, art, architecture, simulation, and visualization programs.<ref>{{cite web|url=http://www.develop-online.net/interview/putting-unreal-engine-in-the-classroom/0197275 |title=Putting Unreal Engine in the classroom |work=[[Develop (magazine)|Develop]] |publisher=Intent Media |date=September 4, 2014 |accessdate=September 5, 2014 |first=James |last=Batchelor |deadurl=no |archiveurl=https://web.archive.org/web/20140906085140/http://www.develop-online.net/interview/putting-unreal-engine-in-the-classroom/0197275 |archivedate=September 6, 2014 }}</ref><ref>{{Cite web |url=https://www.pcgamer.com/unreal-engine-4-now-free-for-academic-use/ |title=Unreal Engine 4 now free for academic use |last=Sykes  |first=Tom |date=September 5, 2014 |website=[[PC Gamer]] |access-date=April 4, 2018}}</ref> On February 19, 2015, Epic launched ''Unreal Dev Grants'', a $5 million development fund aiming to provide grants to creative projects using Unreal Engine 4.<ref>{{cite web|url=http://www.gamasutra.com/view/news/236807/Epic_Games_offers_up_5_million_in_Unreal_Dev_Grants.php |title=Epic Games offers up $5 million in Unreal Dev Grants |work=[[Gamasutra]] |publisher=[[UBM plc]] |date=February 19, 2015 |accessdate=March 11, 2015 |first=Christian |last=Nutt |deadurl=no |archiveurl=https://web.archive.org/web/20150312070425/http://www.gamasutra.com/view/news/236807/Epic_Games_offers_up_5_million_in_Unreal_Dev_Grants.php |archivedate=March 12, 2015 }}</ref>

[[File:Unreal Engine booth (cropped).jpg|thumb|280px|An Unreal Engine booth at GDC 2017]]
During the March 2015 Game Developers Conference, Epic announced that they would release Unreal Engine 4, along with all future updates, for free for all users.<ref name="fortune ue4 free"/><ref>{{cite web|url=http://www.ign.com/articles/2015/03/02/unreal-engine-4-is-free-for-everyone |title=Unreal Engine 4 is Free for Everyone |work=[[IGN]] |publisher=[[Ziff Davis]] |date=March 2, 2015 |accessdate=March 12, 2015 |first=Jordan |last=Sirani |deadurl=no |archiveurl=https://web.archive.org/web/20150314224919/http://www.ign.com/articles/2015/03/02/unreal-engine-4-is-free-for-everyone |archivedate=March 14, 2015 }}</ref><ref>{{cite web|url=http://www.gamasutra.com/view/news/237724/Unreal_Engine_4_is_now_freetodownload_for_everyone.php |title=Unreal Engine 4 is now free-to-download for everyone |work=[[Gamasutra]] |publisher=[[UBM plc]] |date=March 2, 2015 |accessdate=March 12, 2015 |first=Christian |last=Nutt |deadurl=no |archiveurl=https://web.archive.org/web/20150315054400/http://www.gamasutra.com/view/news/237724/Unreal_Engine_4_is_now_freetodownload_for_everyone.php |archivedate=March 15, 2015 }}</ref> In exchange, Epic established a selective royalty schedule, asking for 5% of revenue for products that make more than $3,000 per quarter, as well as establishing an Unreal Marketplace for users to sell content with Epic taking a cut of sales from this as well.<ref name="fortune ue4 free">{{cite web|url=http://fortune.com/2015/03/03/epic-games-unreal-tech-free/ |title=Why Epic Games is giving away its game technology |work=[[Fortune (magazine)|Fortune]] |publisher=[[Time Inc.]] |date=March 3, 2015 |accessdate=March 13, 2015 |first=John |last=Gaudiosi |deadurl=no |archiveurl=https://web.archive.org/web/20150308142904/http://fortune.com/2015/03/03/epic-games-unreal-tech-free/ |archivedate=March 8, 2015 }}</ref><ref>{{Cite web |url=http://www.escapistmagazine.com/news/view/137229-Epic-Games-Unreal-Engine-Marketplace-Open-UE4-Unreal-Tournament-2014 |title=Epic Games Opens Unreal Engine Marketplace to Developers - Update |last=Devin |first=Connors |date=September 3, 2014 |website=[[The Escapist (magazine)|The Escapist]] |access-date=August 21, 2018}}</ref> Sweeney stated that when they moved to the subscription model in 2014, use of Unreal grew by 10 times and through many smaller developers, and believed that they would draw even more uses through this new pricing scheme.<ref name="fortune ue4 free"/> 

In an attempt to attract Unreal Engine developers, [[Oculus VR]] announced in October 2016 that it will pay royalty fees for all Unreal-powered [[Oculus Rift]] titles published on their store for up to the first $5 million of gross revenue per game.<ref>{{cite web|url=http://www.gamasutra.com/view/news/282872/Oculus_Epic_make_deal_to_give_Unreal_Engine_devs_a_royalties_break.php |title=Oculus, Epic make deal to give Unreal Engine devs a royalties break |website=[[Gamasutra]] |date=October 6, 2016 |accessdate=October 29, 2016 |last=Graft |first=Kris |deadurl=no |archiveurl=https://web.archive.org/web/20161030002552/http://www.gamasutra.com/view/news/282872/Oculus_Epic_make_deal_to_give_Unreal_Engine_devs_a_royalties_break.php |archivedate=October 30, 2016 }}</ref>

To prepare for the release of its free-to-play [[battle royale game|"Battle Royale"]] mode in ''[[Fortnite]]'' in September 2017, Epic had to make a number of Unreal Engine modifications that helped it to handle a large number (up to 100) of connections to the same server while still retaining high bandwidth, and to improve the rendering of a large open in-game world. Epic will incorporate these changes into future updates of the Unreal Engine.<ref>{{cite web | url = https://www.gamasutra.com/view/news/307051/Developing_Fortnite_Battle_Royale_prompted_enginewide_Unreal_improvements.php | title = Developing Fortnite: Battle Royale prompted engine-wide Unreal improvements | first = Alissa | last = McAloon | date = October 4, 2017 | accessdate = October 4, 2017 | work = [[Gamasutra]] | deadurl = no | archiveurl = https://web.archive.org/web/20180224221214/https://www.gamasutra.com/view/news/307051/Developing_Fortnite_Battle_Royale_prompted_enginewide_Unreal_improvements.php | archivedate = February 24, 2018 | df = mdy-all }}</ref>

With the opening of the [[Epic Games Store]] in December 2018, Epic will not charge the 5% revenue fee on games that use the Unreal Engine and released through the Epic Games Stores, absorbing that cost as part of the base 12% cut Epic is taking to cover other costs.<ref>{{Cite web |last1=Frank |first1=Allegra |title=Epic Games is launching its own store, and taking a smaller cut than Steam |work=[[Polygon (website)|Polygon]] |date=December 4, 2018 |url=https://www.polygon.com/2018/12/4/18125498/epic-games-store-details-revenue-split-launch-date |language=en-US |accessdate=December 7, 2018  }}</ref> 

==== Supported platforms ====

{{columns-list|
* [[Microsoft Windows]]<ref name="techcrunch">{{Cite web |url=https://techcrunch.com/2014/04/03/unreal-engine-4-gets-support-for-making-linux-games/ |title=Unreal Engine 4 Gets Support For Making Linux And SteamOS Games |last=Kumparak |first=Greg |date=April 3, 2014 |website=[[TechCrunch]] |archive-url=https://web.archive.org/web/20170810155811/https://techcrunch.com/2014/04/03/unreal-engine-4-gets-support-for-making-linux-games/ |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[macOS]]<ref name="techcrunch"/>
* [[Linux]]<ref name="techcrunch"/>
* [[SteamOS]]<ref name="techcrunch"/>
* [[HTML5]]<ref>{{Cite web |url=http://www.gamasutra.com/view/news/189583/Interview_Epic_goes_allin_on_HTML5_with_UE4_support.php |title=Interview: Epic goes all-in on HTML5 with UE4 support |last=Cifaldi |first=Frank |date=March 29, 2013 |website=[[Gamasutra]] |archive-url=https://web.archive.org/web/20170810171622/http://www.gamasutra.com/view/news/189583/Interview_Epic_goes_allin_on_HTML5_with_UE4_support.php |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[iOS]]<ref name="techcrunch"/>
* [[Android (operating system)|Android]]<ref name="techcrunch"/>
* [[Nintendo Switch]]<ref>{{Cite web |url=http://www.ign.com/articles/2016/10/21/nintendo-switch-will-support-unreal-engine-4 |title=Nintendo Switch Will Support Unreal Engine 4 |last=Skrebels |first=Joe |date=October 16, 2016 |website=[[IGN]] |archive-url=https://web.archive.org/web/20170801042012/http://www.ign.com/articles/2016/10/21/nintendo-switch-will-support-unreal-engine-4 |archive-date=August 1, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[PlayStation 4]]<ref name="escapist">{{Cite web |url=http://www.escapistmagazine.com/news/view/133982-Epic-Adds-Xbox-One-PlayStation-4-Support-to-Unreal-Engine-4-1 |title=Epic Adds Xbox One, PlayStation 4 Support to Unreal Engine 4.1 |last=Connors |first=Devin |date=April 24, 2014 |website=[[The Escapist (magazine)|The Escapist]] |archive-url=https://web.archive.org/web/20170810160803/http://www.escapistmagazine.com/news/view/133982-Epic-Adds-Xbox-One-PlayStation-4-Support-to-Unreal-Engine-4-1 |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[Xbox One]]<ref name="escapist"/>
* Magic Leap One<ref>{{Cite web |url=https://www.vrfocus.com/2018/03/magic-leap-release-developer-sdk-unreal-engine-4-support-announced/ |title=Magic Leap Release Developer SDK, Unreal Engine 4 Support Announced |last=Koolonavich |first=Nikholai |date=March 19, 2018 |website=VRFocus |archive-url=https://web.archive.org/web/20180319192931/https://www.vrfocus.com/2018/03/magic-leap-release-developer-sdk-unreal-engine-4-support-announced/ |archive-date=March 19, 2018 |dead-url=no |access-date=March 19, 2018}}</ref>
* [[HTC Vive]]<ref>{{Cite web |url=https://www.theverge.com/2015/4/30/8519631/unreal-engine-4-steamvr-vive-support |title=Steam's virtual reality just got a boost from the maker of Unreal Tournament |last=Kastrenakes |first=Jacob |last2=Robertson |first2=Adi |date=April 30, 2015 |website=[[The Verge]] |archive-url=https://web.archive.org/web/20170810164836/https://www.theverge.com/2015/4/30/8519631/unreal-engine-4-steamvr-vive-support |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[Oculus Rift]]<ref>{{Cite web |url=http://www.pcgamer.com/unreal-engine-4-gets-oculus-rift-support-could-spell-good-things-for-future-indie-games/ |title=Unreal Engine 4 gets Oculus Rift support, could spell good things for future indie games |last=Sykes |first=Tom |date=June 9, 2013 |website=[[PC Gamer]] |archive-url=https://web.archive.org/web/20170810165737/http://www.pcgamer.com/unreal-engine-4-gets-oculus-rift-support-could-spell-good-things-for-future-indie-games/ |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[PlayStation VR]]<ref>{{Cite web |url=https://www.vrfocus.com/2014/06/unreal-engine-4-2-update-adds-project-morpheus-support-ps4-pc/ |title=Unreal Engine 4.2 Update Adds Project Morpheus Support On PS4 & PC |last=Feltham |first=Jamie |date=June 5, 2014 |website=VRFocus |archive-url=https://web.archive.org/web/20170810170639/https://www.vrfocus.com/2014/06/unreal-engine-4-2-update-adds-project-morpheus-support-ps4-pc/ |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[Google Daydream]]<ref>{{Cite web |url=http://www.gamasutra.com/view/news/273018/Googles_new_VR_headset_gets_Unreal_Engine_4_support.php |title=Google's new VR headset gets Unreal Engine 4 support |last=Graft |first=Kris |date=May 19, 2016 |website=[[Gamasutra]] |archive-url=https://web.archive.org/web/20170810162414/http://www.gamasutra.com/view/news/273018/Googles_new_VR_headset_gets_Unreal_Engine_4_support.php |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[OSVR]]<ref>{{Cite web |url=https://techcrunch.com/2016/03/15/native-osvr-support-comes-to-unreal-game-engine/ |title=Native OSVR support comes to Unreal game engine |last=Matney |first=Lucas |date=March 15, 2016 |website=[[TechCrunch]] |archive-url=https://web.archive.org/web/20170810162724/https://techcrunch.com/2016/03/15/native-osvr-support-comes-to-unreal-game-engine/ |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[Samsung Gear VR]]<ref>{{Cite web |url=https://www.roadtovr.com/samsung-gear-vr-project-tango-ue4/ |title=Samsung Gear VR and Google Project Tango Support Coming to Unreal Engine 4 |last=Lang |first=Ben |date=September 16, 2014 |website=Road To VR |archive-url=https://web.archive.org/web/20170810163524/https://www.roadtovr.com/samsung-gear-vr-project-tango-ue4/ |archive-date=August 10, 2017 |dead-url=no |access-date=August 10, 2017}}</ref>
* [[HoloLens 2]]<ref>{{Cite web |url=https://www.unrealengine.com/en-US/blog/unreal-engine-4-support-for-hololens-2-released-in-early-access |title=Unreal Engine 4 support for HoloLens 2 released in early access |last=Ryan |first=Vance |date=May 31, 2019 |website=Unreal Engine |access-date=June 11, 2019}}</ref>
}}

== UnrealScript ==
{{Infobox programming language
| name             = UnrealScript
| paradigm         = [[Object-oriented programming|Object-oriented]], [[Generic programming|generic]]
| released         = {{Start date and age|May 1998}}
| developer        = [[Tim Sweeney (game developer)|Tim Sweeney]]
| typing           = [[Type system|Static, strong, safe]]
| influenced by    = [[C++]], [[Java (programming language)|Java]]
| operating system = [[Cross-platform|Cross-platform (multi-platform)]]
| website          = [https://api.unrealengine.com/udk/Three/UnrealScriptHome.html api.unrealengine.com]
| file ext         = .uc .uci .upkg
}}

UnrealScript (often abbreviated to UScript) was Unreal Engine's native scripting language used for authoring game code and [[gameplay]] events before the release of Unreal Engine 4. The language was designed for simple, [[high-level programming language|high-level]] [[game programming]].<ref>{{cite web|url=http://udn.epicgames.com/Three/UnrealScriptReference.html#Design%20goals%20of%20_UnrealScript |title=UDN - Three - UnrealScriptReference |publisher=Udn.epicgames.com |date= |accessdate=June 26, 2013 |deadurl=no |archiveurl=https://web.archive.org/web/20130703145732/http://udn.epicgames.com/Three/UnrealScriptReference.html |archivedate=July 3, 2013 }}</ref> The UnrealScript interpreter was programmed by Sweeney, who also created an earlier game scripting language, ZZT-oop.<ref name="uhistory"/>

Similar to [[Java (programming language)|Java]], UnrealScript is [[object-oriented]] without [[multiple inheritance]] (classes all inherit from a common Object class), and classes are defined in individual files named for the class they define. Unlike [[Java (programming language)|Java]], UnrealScript does not have object wrappers for primitive types. Interfaces are only supported in Unreal Engine generation 3 and a few Unreal Engine 2 games. UnrealScript supports [[operator overloading]], but not [[method overloading]], except for optional parameters.

At the 2012 Game Developers Conference, Epic announced that UnrealScript was being removed from Unreal Engine 4 in favor of [[C++]].<ref>{{Cite web |url=http://gameindustry.about.com/od/trends/a/Unreal-Engine-4-First-Look.htm |title=Unreal Engine 4 - First Look |last=Schultz |first=Warren |website=[[About.com]] |archive-url=https://web.archive.org/web/20120524062935/http://gameindustry.about.com/od/trends/a/Unreal-Engine-4-First-Look.htm |archive-date=May 24, 2012 |dead-url=yes |access-date=December 29, 2017}}</ref> [[Visual programming language|Visual scripting]] would be supported by the Blueprints Visual Scripting system, a replacement for the earlier Kismet visual scripting system.<ref name="gamasutra"/><ref name="rps">{{Cite web |url=https://www.rockpapershotgun.com/2012/07/20/fortnites-jessen-talks-minecraft-pc-gaming-ue4/ |title=Fortnite’s Jessen Talks Minecraft, PC Gaming, UE4 |last=Grayson |first=Nathan |date=July 20, 2012 |website=[[Rock, Paper, Shotgun]] |access-date=May 1, 2018}}</ref>

{{quotation|One of the key moments in Unreal Engine 4's development was, we had a series of debates about UnrealScript – the scripting language I'd built that we'd carried through three generations. And what we needed to do to make it competitive in the future. And we kept going through bigger and bigger feature lists of what we needed to do to upgrade it, and who could possibly do the work, and it was getting really, really unwieldy. And there was this massive meeting to try and sort it out, and try to cut things and decide what to keep, and plan and...there was this point where I looked at that and said 'you know, everything you're proposing to add to UnrealScript is already in C++. Why don't we just kill UnrealScript and move to pure C++? You know, maximum performance and maximum debuggability. It gives us all these advantages.'|Sweeney, ''[[Gamasutra]]'', 2017<ref name="gamasutra2">{{Cite web |url=http://www.gamasutra.com/view/news/292573/For_Tim_Sweeney_advancing_Epic_means_racing_into_AR_and_VR.php |title=For Tim Sweeney, advancing Epic means racing into AR and VR |last=Wawro |first=Alex |date=March 1, 2017 |website=[[Gamasutra]] |archive-url=https://web.archive.org/web/20170720205027/http://www.gamasutra.com/view/news/292573/For_Tim_Sweeney_advancing_Epic_means_racing_into_AR_and_VR.php |archive-date=July 20, 2017 |dead-url=no |access-date=July 19, 2017}}</ref>}}

==See also==
* [[List of Unreal Engine games]]

==References==
[https://en.wikipedia.org/wiki/Unreal_Engine Wikipedia Unreal Engine 4 page]

==External links==
{{Commons category|Unreal Engine}}
*{{official website}}

{{portal bar|1990s|Computer graphics|Information technology|Video games}}
{{Unreal|state=uncollapsed}}
{{Epic |state=autocollapse}}
{{Video game engines |state=autocollapse}}

[[Category:1998 software]]
[[Category:3D graphics software]]
[[Category:Articles containing video clips]]
[[Category:Epic Games]]
[[Category:Game engines for Linux]]
[[Category:Game engines that support Mantle]]
[[Category:Game engines that support Vulkan]]
[[Category:Global illumination software]]
[[Category:IPhone video game engines]]
[[Category:Software development kits|Unreal S]]
[[Category:Unreal (video game series)]]
[[Category:Unreal Engine]]
[[Category:Video game development software]]
[[Category:Video game engines]]
[[Category:Video game IDE]]
[[Category:Virtual reality]]