Unreal Engine 4 is a game engine developed by Epic Games, and is the current release of the Unreal Engine. Unreal Engine 4 was unveiled to limited attendees at the 2012 Game Developers Conference in May 2012.
On August 17, 2005, Mark Rein, the vice-president of Epic Games, revealed that Unreal Engine 4 had been in development since 2003. Until mid-2008, development was exclusively done by Tim Sweeney, CEO and founder of Epic Games. The engine targets the eighth generation of consoles, PCs and Tegra K1-based devices running Android announced in January 2014 at CES.
In February 2012, Mark Rein said "people are going to be shocked later this year when they see Unreal Engine 4". Unreal Engine 4 was unveiled to limited attendees at the 2012 Game Developers Conference, and video of the engine being demonstrated by technical artist Alan "Talisman" Willard was released to the public on June 7, 2012 via GameTrailers TV. This demo was created on a PC with triple GeForce GTX 580 (tri SLI) and can be run on a PC with a GeForce GTX 680.
One of the major features planned for UE4 was real-time global illumination using voxel cone tracing, eliminating pre-computed lighting. However, this feature has been replaced with a similar but less computationally-expensive algorithm prior to release for all platforms including the PC because of performance concerns on next-generation consoles. UE4 also includes new developer features to reduce iteration time, and allows updating of C++ code while the engine is running. The new "Blueprint" visual scripting system (a successor to UE3's "Kismet") allows for rapid development of game logic without using C++, and includes live debugging. The result is reduced iteration time, and less of a divide between technical artists, designers, and programmers.
- "[In older engines], if you wanted to change the relationship between your weapon damage and how long it'll take to kill a creature, you may spend a couple of days iterating, but if you have to spend a lot of time waiting for a build every time, you're talking one change, waiting 15 minutes for the compile to complete, and then play the game, get to the point where you can test it, test it, exit the game, change, compile...now, since all of that can be done very quickly within the tools, it's ‘Make the change, play, when it compiles, finish, shoot the guy, and then escape, make the change, play.. the iteration time is down to 30 seconds instead of 15 minutes. Our ability to kind of roll through and see how the game is playing out is much faster."
- ―Alan Willard, writing for Kotaku
As of March 2, 2015, Unreal Engine 4 is available to everyone for free, along with all future updates, with a selective royalty schedule. Oculus VR announced in October 2016 that it will cover royalty fees for all Unreal Engine titles shipping on the Oculus Store for up to the first $5 million of gross revenue per game. The same month, Unreal Engine 4 support was confirmed for Nintendo's hybrid console, the Nintendo Switch.