Unreal Engine

Unreal Engine 1

Making its debut in 1998 with Unreal, the first generation Unreal Engine integrated rendering, collision detection, AI, visibility, networking, scripting, and file system management into one complete engine. Unreal Engine 1 provided an advanced software rasterizer and a hardware-accelerated rendering path using the Glide API, specifically developed for 3dfx GPUs, and was updated for OpenGL and Direct3D. The release of Unreal Tournament marked great strides in both network performance and Direct3D and OpenGL support.

The engine became popular due to the modular engine architecture and the inclusion of a scripting language called UnrealScript, which made it easy to mod, including total conversions like Tactical Ops.

From the start, the engine was designed in a way to be extensible and improved over multiple generations of games, as creator and founder of Epic Games Tim Sweeney stated in a 1998 interview with magazine Maximum PC.

Unreal Engine 2

The second version was released in 2002 with America's Army, a free multiplayer shooter created by the US Army and financed by the U.S. government. This generation saw the core code and rendering engine completely re-written. In addition, it featured UnrealEd 2, a level editor, which debuted with the previous generation of the engine and was shortly followed later by UnrealEd 3, along with the Karma physics SDK. This physics engine powered the ragdoll physics in Unreal Tournament 2003 and Unreal Championship. Other engine elements were also updated, with improved assets as well as adding support for the GameCube and the Xbox. Support for the PlayStation 2 console was previously added in UE1. Taking Xbox aside, both GameCube and PS2 were never supported directly by Epic, support being instead farmed out to Secret Level. As such, third parties looking to use further Unreal Engine revisions had to do their own builds throughout the generation, as they had to in more recent years with the Wii, X360, PS3, PSP, and 3DS.

UE2.5, an update to the original version of UE2, improved rendering performance and added vehicles physics, a particle system editor for UnrealEd, and 64-bit support in Unreal Tournament 2004. A specialized version of UE2.5 called UE2X was used for Unreal Championship 2: The Liandri Conflict on the original Xbox platform. It features optimizations specific to that console. EAX 3.0 is also supported for sound.

In March 2011, Ubisoft Montreal revealed that UE2 was successfully running on the Nintendo 3DS.

Unreal Engine 3

The first screenshots of Unreal Engine 3 were presented in 2004, at which point the engine had already been in development for 18 months. Unlike Unreal Engine 2, which still supported fixed-function pipeline, Unreal Engine 3 was designed to take advantage of fully programmable shader hardware (in DirectX 9 terms, it required shader model 3.0). All lighting calculations were done per-pixel, instead of per-vertex. Unreal Engine 3 supports a gamma-correct high-dynamic range renderer.

Initially, Unreal Engine 3 only supported Windows, PlayStation 3, and Xbox 360 platforms, while iOS and Android were added later in 2010 (with Infinity Blade being the first iOS title and Dungeon Defenders the first Android title). OS X support was added in 2011. Its renderer supports techniques including HDRR, per-pixel lighting, and dynamic shadows. In October 2011, the engine was ported to support Adobe Flash Player 11 through the Stage 3D hardware-accelerated APIs. Epic has used this version of the engine for their in-house games. Aggressive licensing of this iteration has garnered a great deal of support from many prominent licensees. Epic has announced that Unreal Engine 3 runs on both Windows 8 and Windows RT.

Throughout the lifetime of UE3, significant updates have been incorporated, including a global illumination solver, improved destructible environments, soft body dynamics, large crowd simulation, iPod Touch functionality, Steamworks integration, a real-time global illumination solution, and stereoscopic 3D on Xbox 360 via TriOviz for Games Technology. DirectX 11 support was demonstrated with the Samaritan demo, which was built by Epic Games in a close partnership with NVIDIA, with engineers working around the country to push real-time graphics to a new high point.

In addition to the game industry, UE3 has also seen adoption by many non-gaming projects. The popular children's TV show LazyTown used UE3 during filming to generate virtual sets for real-time integration with footage of actors and puppets performing in front of green screens. In March 2012, the FBI licensed Epic's Unreal Engine 3 to use in a simulator for training. The animation software "Muvizu Play", which was released in April 2013, uses UE3.

Unreal Development Kit

While Unreal Engine 3 has been quite open for modders to work with, the ability to publish and sell games made using UE3 was restricted to licensees of the engine. However, in November 2009, Epic released a free version of UE3's SDK, called the Unreal Development Kit (UDK), that is available to the general public.

The December 2010 UDK release added support for creating iOS games and apps. As of the September 2011 release, iOS, OS X and Windows platforms all support UDK-created games.

Unreal Engine 4

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.

On March 19, 2014, at the Game Developers Conference, Epic Games released Unreal Engine 4, and all of its tools, features and complete C++ source code, to the development community through a new subscription model. Anyone can sign up for UE4 for Windows, OS X, iOS and Android by paying $19 per month, plus 5% of gross revenue resulting from any commercial products built using UE4. CEO and founder of Epic Games, Tim Sweeney, said that the new business model is a reflection of changes in the industry. Epic Games has traditionally made its Unreal Engine available to large AAA game development teams at a cost of millions of dollars but as the industry has evolved, Epic has had to "really rethink our whole business as to how we make the engine available to teams." "Looking at the new shape of the industry now, we realize that's an outdated tool," Sweeney said. "Looking at the possibilities for the engine, we started from scratch and thought 'How can we make the engine available to more people?'". According to the Unreal Engine website, subscribers to the engine will be able to cancel and renew their subscription at any time. They will be able to retain access to UE4 tools, but will not receive access to future releases of Unreal Engine 4.

On September 3, 2014, Epic Games launched the Unreal Engine Marketplace, allowing UE4 subscribers to buy and sell community-created content of all shapes and sizes. In addition to all of the previously released free content, the new marketplace came with a variety of asset packs including full-scale environments, props, characters, sounds, materials, animated meshes, prefab C++ code and a number of other asset types as well as free demos and tutorials.

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.

On February 19, 2015, Epic launched Unreal Dev Grants, a $5,000,000 development fund designed to provide financial grants to innovative projects being built with Unreal Engine 4.

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 the new console Nintendo Switch.

UnrealScript

UnrealScript (often abbreviated to UScript) is 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 game programming. The UnrealScript interpreter was programmed by Tim Sweeney, who also created an earlier game scripting language, ZZT-oop.

Similar to 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, 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.

In March 2014 Epic announced that the Unreal Engine 4 would no longer be supporting UnrealScript, but instead support game scripting in C++. Visual scripting would be supported by the Blueprints Visual Scripting system, a replacement for the earlier Kismet visual scripting system.

Licensees

The Unreal engine technology is licensed to many notable entities in the fields of education, training simulation, construction simulation, virtual reality, and CG animation. Licensees include many universities, corporations, the U.S. Army the U.S. Air Force, NASA the Federal Bureau of Investigation (FBI), the Michigan Department of Transportation (MDOT), and The Science and Technology Directorate (DHS S&T).

Awards and accolades

Unreal Engine 3 received the Game Developer Magazine Front Line Awards for "Best Game Engine" (2004, 2005, 2006, 2007, Hall of Fame, 2009, 2010, 2011, 2012). It received IGN's Best of E3 2005 for "Technological Excellence", and the Develop Industry Excellence Awards for "Best Game Engine" (2009, 2010, 2011).

Unreal Engine 4 received GamesRadar's E3 2012 Important Stuff Awards for "Best Taste of Next-Gen". IGN's Best of E3 2012 for "Coolest Tech", Game Informer's Best of E3 2012 Awards for "Best Tech", and was declared "Best Game Engine" in Develop 100: The Tech List 2014. It also received the Develop Industry Excellence Awards for "Best Game Engine" (2013, 2016)

In 2014, the Unreal technology received the Guinness World Record award for "Most Successful Videogame Engine".