Unreal Engine (UE in short) is a game engine developed by Epic Games, first showcased in the 1998 first-person shooter game Unreal. Initially developed for PC first-person shooters, it has since been used in a variety of genres of three-dimensional (3D) games and has seen adoption by other industries, most notably the film and television industry. Written in C++, the Unreal Engine features a high degree of portability, supporting a wide range of desktop, mobile, console and virtual reality platforms.
The first-generation Unreal Engine was developed by Tim Sweeney, the founder of Epic Games. Having created editing tools for his shareware games ZZT (1991) and Jill of the Jungle (1992), Sweeney began writing the engine in 1995 for the production of a game that would later become a first-person shooter known as Unreal.
In October 1998, IGN reported, based on an interview with affiliate Voodoo Extreme, that Sweeney was doing research for his next-generation engine. With development starting a year later, the second version made its debut in 2002 with America's Army, a free multiplayer shooter developed by the U.S. Army as a recruitment device.
Unreal Engine 3 were presented by July 2004, at which point the engine had already been in development for over 18 months. The engine was based on the first-generation, but contained new features.
The basic architectural decisions visible to programmers of an object-oriented design, a data-driven scripting approach, and a fairly modular approach to subsystems still remain [from Unreal Engine 1]. But the parts of the game that are really visible to gamers the renderer, the physics system, the sound system, and the tools– are all visibly new and dramatically more powerful
In August 2005, Mark Rein, the vice-president of Epic Games, revealed that Unreal Engine 4 had been in development for two years.
Unreal Engine 5 was revealed on May 13, 2020, supporting all existing systems including the next-generation consoles PlayStation 5 and Xbox Series X/S. Work on the engine started about two years prior to its announcement. It was released in early access on May 26, 2021, with expected full launch in early 2022.
The Unreal Engine has found use in film making to create virtual sets that can track with a camera's motion around actors and objects and be rendered in real time to large LED screens and atmospheric lighting systems. This allows for real-time composition of shots, immediate editing of the virtual sets as needed, and the ability to shoot multiple scenes within a short period by just changing the virtual world behind the actors. The overall appearance was recognized to appear more natural than typical chromakey effects.
The Unreal Engine was primarily designed to be used as the underlying technology for video games. Besides Epic's own games, including Gears of War and Fortnite, the engine is used in a number of high-profile game titles, including PlayerUnknown's Battlegrounds, Final Fantasy VII Remake, Valorant and Yoshi’s Crafted World