Unreal Engine (UE) is a 3D computer graphics 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 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 latest generation, Unreal Engine 5, was launched in April 2022. As its predecessor released in March 2014, its source code is available on GitHub after registering an account, and commercial use is granted based on a royalty model. 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.After years in development, it debuted with the game's release in 1998,although MicroProse and Legend Entertainment had access to the technology much earlier, licensing it in 1996.According to an interview, Sweeney wrote 90 percent of the code in the engine, including the graphics, tools, and networking.
At first, the engine relied completely on software rendering, meaning the graphics calculations were handled by the CPU. However, over time, it was able to take advantage of the capabilities provided by dedicated graphics cards, focusing on the Glide API, specially designed for 3dfx accelerators.While OpenGL and Direct3D were supported, they reported a slower performance compared to Glide due to their deficiency in texture management at the time.
"The Unreal engine has raised the bar on what action gamers expect from future products. The visual effects first seen in the game will become expected from future games."
Harry Potter and the Sorcerer's Stone for PC was developed with the Unreal Tournament version of the engine using assets from the 2001 film
Unreal was noted for its graphical innovations, but Sweeney recognized in a 1999 interview with Eurogamer that many aspects of the game were unpolished, citing complaints from gamers about its high system requirements and online gameplay issues.Epic addressed these points during the development of Unreal Tournament by incorporating several enhancements in the engine intended to optimize performance on low-end machines and improve the networking code, while also refining the artificial intelligence for bots to display coordination in team-based environments.The game also came with increased image quality with the support for the S3TC compression algorithm, allowing for 24-bit high resolution textures without compromising performance.In addition to being available on Microsoft Windows, Linux, Mac and Unix,the engine was ported through Unreal Tournament to the PlayStation 2 and, with the help of Secret Level, to the Dreamcast.
By late 1999, The New York Times indicated that there had been sixteen external projects using Epic's technology, including Deus Ex, The Wheel of Time, and Duke Nukem Forever,the latter of which was originally based on the Quake II engine.Unlike id Software, whose engine business only offered the source code, Epic provided support for licensees and met with them to discuss improvements to its game development system.While it cost around $3 million to produce and licenses for up to $350,000,Epic gave players the ability to modify its games with the incorporation of UnrealEd and a scripting language called UnrealScript, sparking a community of enthusiasts around a game engine built to be extensible over multiple generations of games.