Unreal Engine

src: docs.unrealengine.com

The Unreal Engine is a game engine developed by Epic Games, first showcased in the 1998 first-person shooter game Unreal. Although primarily developed for first-person shooters, it has been successfully used in a variety of other genres, including stealth, MMORPGs, and other RPGs. With its code written in C++, the Unreal Engine features a high degree of portability and is a tool used by many game developers today. It has won several awards, including the Guinness World Records award for "most successful video game engine."

The current release is Unreal Engine 4, designed for Microsoft Windows, macOS, Linux, SteamOS, HTML5, iOS, Android, Nintendo Switch, PlayStation 4, Xbox One and virtual reality (SteamVR/HTC Vive, Oculus Rift, PlayStation VR, Google Daydream, OSVR and Samsung Gear VR).

Video Unreal Engine

History

Unreal Engine 1

Development of the first generation Unreal Engine was carried out by the founder of Epic Games, Tim Sweeney. Inspired by John Carmack's pioneering programming work on Doom and then Quake, Sweeney started the engine in 1995 for the production of a game that would later become known as Unreal, a first-person shooter set in a medieval world. After three years of development, the engine debuted with the game's release in 1998, although licensees such as MicroProse and Legend Entertainment had possessed the technology much earlier, with the first licensing deal taking place in 1996.

Both software and hardware rendering were present in the foundational software, as well as collision detection, colored lighting, and a rudimentary version of texture filtering. The engine also provided a level editor called UnrealEd, which had support for real-time constructive solid geometry operations as early as 1996, allowing mappers to change the level layout "on the fly". Other features implemented during development included real-time direct illumination and light sourcing, which were respectively integrated in 1995 and 1997. In addition to having support for Microsoft Windows, Linux and Mac, Unreal Tournament also opened the platform to PlayStation 2 and Dreamcast, with the latter being supported directly by Secret Level, now known as Sega Studios San Francisco. In 2000, Epic updated the engine with new improvements, including higher-polygon models and architecture, a skeletal animation system and large-scale terrain 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. This modular nature meant that the engine could be extensible and improved over multiple generations of games, as Sweeney stated in a 1998 interview with magazine Maximum PC:

The big goal with the Unreal technology all long was to build up a base of code that could be extended and improved through many generations of games. Meeting that goal required keeping the technology quite general-purpose, writing clean code, and designing the engine to be very extensible. The early plans to design an extensible multi-generational engine happened to give us a great advantage in licensing the technology as it reached completion. After we did a couple of licensing deals, we realised it was a legitimate business. Since then, it has become a major component of our strategy.

Unreal Engine 2

The second version made its debut in 2002 with America's Army, a free multiplayer shooter created by the US Army. While the basic structure of the engine was used, this generation saw the renderer completely re-written, and integrated a number of features, such as the Matinee cinematic editing tool, export plug-ins for 3D Studio Max and Maya, and the Karma physics engine, a tool by Math Engine that powered the ragdoll physics in Unreal Tournament 2003. In addition, it featured UnrealEd 2, which debuted with the previous generation of the engine and was shortly followed later by UnrealEd 3. Other engine elements were also updated, with improved assets as well as adding support for the Xbox.

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 called UE2X was used for Unreal Championship 2: The Liandri Conflict on the original Xbox platform, featuring optimizations specific to that console.

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. On the rendering side, Unreal Engine 3 provided support for a gamma-correct high-dynamic range renderer.

Initially, Unreal Engine 3 only supported Windows, PlayStation 3, and Xbox 360 platforms, while iOS (first demonstrated with Epic Citadel) 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. The same year it was announced that the engine would support Adobe Flash Player 11 through the Stage 3D hardware-accelerated APIs and that it was being used in two Wii U games, Batman: Arkham City and Aliens: Colonial Marines. Windows 8 and Windows RT support was added in 2012. In 2013, Epic teamed-up with Mozilla to bring Unreal Engine 3 to HTML5. Using the asm.js sublanguage and Emscripten compiler, they were able to port the engine to JavaScript and WebGL in four days.

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 unveiled at the 2011 Game Developers Conference and 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.

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.

In December 2010, it was updated to include support for creating iOS games and apps.

Unreal Engine 4

In August 2005, Mark Rein, the vice-president of Epic Games, revealed that Unreal Engine 4 had been in development since 2003. Until 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.

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. 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?'".

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 million development fund designed to provide financial grants to innovative projects being built with UE4.

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 currently supported platforms are Microsoft Windows, macOS, Linux, SteamOS, HTML5, iOS, Android, Nintendo Switch, PlayStation 4, Xbox One and virtual reality (SteamVR/HTC Vive, Oculus Rift, PlayStation VR, Google Daydream, OSVR and Samsung Gear VR).

To prepare for the release of its free-to-play "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) 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.

Maps Unreal Engine

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.

src: cdn2.unrealengine.com

Reception

Licensees

In addition to the game industry, the Unreal Engine has also seen adoption by many non-gaming projects. For instance, visual effects company Industrial Light & Magic employed the Unreal Tournament version of the engine to recreate Rouge City, a fictional place in the 2001 film A.I. Artificial Intelligence, in order to help Steven Spielberg plan out camera angles for scenes set in Rouge City. The popular children's TV show LazyTown used Unreal Engine 3 during filming to generate virtual sets for real-time integration with footage of actors and puppets performing in front of green screens. On the architectural side, HKS announced in 2007 that it had licensed UE3 to produce detailed interactive environments of its projects. Among them was the Cowboys Stadium, whose owners were able to explore its design before construction was completed in 2009. The Unreal Development Kit also was used by the Michigan Department of Transportation, who in 2010 designed a multiscreen driving simulator in a close partnership with Parsons Brinckerhoff to show how vehicles can be plugged in to the national transportation grid. That year also saw the premiere of Chadam, an Unreal Engine 3-powered animated internet series produced by HDFilms and distributed by Warner Bros. Television Group.

In March 2012, Epic Games partnered with Virtual Heroes of Applied Research Associates to launch Unreal Government Network, a program that handles Unreal Engine 3 licenses for government agencies. With this support agreement, Virtual Heroes was able to license the technology to the departments, agencies and units of the United States and its allies across multiple platforms. Epic also revealed that several UGN projects were already underway, including an Intelligence Advanced Research Projects Activity (IARPA) contract for Virtual Heroes to design serious games with the aim to help intelligence analysts tackle instinctual biases that might colour their findings, an anaesthesiology training application for U.S Army physicians, and a multiplayer crime scene training simulation developed by the FBI Academy. Additionally, Epic's tech was also being used by a top five defense contractor and a national laboratory for custom-made model integrations and visualization. Later in December, defense IT and software firm IPKeys Technologies licensed the third version of the engine for development of I-GAME, a tool intended to train tactics and techniques in regards to Counter-IEDs.

In April 2013, the U.S. Air Force licensed the ARA Unreal Engine 3 Web Player, an UE3-based plug-in developed by Virtual Heroes, for use on USAF computers. The same year, IT systems integrator Intelligent Decisions announced that it had become part of the Unreal Government Network. As a new member of the program, the company would improve training simulations with the technology in support of a contract with the U.S. Army Research, Development and Engineering Command (RDECOM). Similarly, the U.S. Department of Homeland Security's Science and Technology Directorate (DHS S&T) and the U.S. Army's Training and Doctrine Command and Research Laboratory used the engine to develop a training platform for first responders titled Enhanced Dynamic Geo-Social Environment (EDGE). Built with a budget of $15 million, the virtual environment was first demonstrated at a police station on November 20, 2013, allowing officers, firefighters, emergency medical professionals, dispatchers and unified command center operators to respond to a virtual active-shooter event inside a model of the Sheraton Grand hotel in downtown Sacramento. On June 26, 2017, the EDGE platform was launched for free for all first responders, and a second training scenario, featuring a school shooting scene, will be released in the fall of 2017.

In 2017, Epic Games held its annual keynote at the Game Developers Conference to showcase features and non-gaming uses for the Unreal Engine. Speaking at the keynote, Industrial Light & Magic's CCO John Knoll and Lucasfilm ADG's Principal Engineer and Architect Naty Hoffman detailed how UE4 was extended to render the droid K-2SO in the 2016 film Rogue One, achieving final pixels on screen while bypassing the traditional pre-rendering process. According to fxguide, the team built on UE4 its own render pipeline, called the ADG's GPU real-time renderer, with which they rendered some shots of the droid that were later included in the film. In an interview with Gamasutra, Tim Sweeney commented: "So final pixels rendered in the Star Wars movie, using the Unreal Engine, in real time. And it went into the movie! These are pixels you see in the movie! It's unbelievable."

Awards and accolades

The Unreal Engine holds several technology awards, including eight Game Developer Magazine Front Line Awards for "Best Game Engine" (2004, 2005, 2006, 2007, 2009, 2010, 2011, 2012), a place in the Front Line Awards Hall of Fame, and six Develop Industry Excellence Awards for "Best Engine" (2009, 2010, 2011 2013, 2016, 2017). It also 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 Engine" in Develop 100: The Tech List 2014.

In 2014, Guinness World Records called the Unreal technology the most successful video game engine.