Unity (game engine)

Unity

Developer(s)	Unity Technologies
Stable release	3.5.5 / August, 2012
Programming language used	C++ JavaScript Boo C#[1]
Operating system	Creation and Deployment[show] Deployment[show]
Type	Game engine
License	Proprietary
Website	www.unity3d.com

Unity is an integrated authoring tool for creating 3D video games or other interactive content such as architectural visualizations^[2] or real-time 3D animations. Unity's development environment runs on Microsoft Windows and Mac OS X, and the games it produces can be run on Windows, Mac, Xbox 360, PlayStation 3, Wii,^[3] iPad, iPhone,^[4], Android, and coming to Linux^[5]. It can also produce browser games that use the Unity web player plugin, supported on Mac and Windows. The web player is also used for deployment as Mac widgets. Unity also has the ability to export games to Adobe's Stage 3D functionality in Flash, but certain features that the web player supports are not usable due to limitations in Flash. Unity is used by over 500,000 game developers.^[6]
Unity consists of both an editor^[7] for developing/designing content and a game engine^[8] for executing the final product. Unity is similar to Director, Blender game engine, Virtools, Torque Game Builder, and Gamestudio, which also use an integrated graphical environment as the primary method of development.
Unity won the Wall Street Journal 2010 Technology Innovation Award in the software category.^[9] Unity was a runner-up for the best use of graphics on Mac OS X at the 2006 Apple Design Awards, losing to the 3D modeling software modo.^[10]

Contents 1 Major features 2 Version control 3 Licensing 4 Future platforms 4.1 Linux 4.2 Roku 2 5 Uses 6 See also 7 References 8 External links

Major features

• Integrated development environment with hierarchical, visual editing, detailed property inspectors and live game preview.^[11][12]
• Deployment on multiple platforms:
  • As a Microsoft Windows or Mac OS X executable
  • As a native Linux executable (coming in version 4.0)
  • On the web (via the Unity Web Player plugin for Internet Explorer, Firefox, Safari, Mozilla, Netscape, Opera, Google Chrome and Camino) on Windows and OS X
  • As a Mac OS X Dashboard widget (no longer available as of Unity version 3.5)
  • For Nintendo Wii^[3] (requires additional license)
  • As an iPhone/iPad application^[4] (requires additional license)
  • For Google Android^[13] (requires additional license)
  • For Google Native Client^[14]
  • For Microsoft Xbox 360 (requires additional license)
  • For Adobe Flash (as of Unity 3.5.1, this is a free feature, but will require an additional license once finalized)^[15]
  • For Sony PlayStation 3 (requires additional license)
  • For BlackBerry PlayBook (requires additional license)^[16]
• Assets loaded into Unity and are automatically imported, and are re-imported if the asset is updated.^[17] Unity supports integration with 3ds Max, Maya, Softimage, Blender, Modo, ZBrush, Cinema 4D, Cheetah3D, Photoshop, Adobe Fireworks and Allegorithmic Substance.
• Graphics engine uses Direct3D (Windows), OpenGL (Mac, Windows), OpenGL ES (iOS, Android), and proprietary APIs (Wii).^[18]
• Support for bump mapping, reflection mapping, parallax mapping, Screen Space Ambient Occlusion, dynamic shadows using shadow maps, render-to-texture and full-screen post processing effects.
• ShaderLab language for using shaders, supporting both declarative "programming" of the fixed-function pipeline and shader programs written in Cg or GLSL.^[19] A shader can include multiple variants and a declarative fallback specification, allowing Unity to detect the best variant for the current video card and if none are compatible, fall back to an alternative shader that may sacrifice features for broader compatibility.
• Built-in support for Nvidia's (formerly Ageia's) PhysX physics engine,^[20] version 2.8.3 (as of Unity 3.0) with added support for real time cloth on arbitrary and skinned meshes, thick ray casts, and collision layers.
• Game scripting via Mono.^[21] Scripting is built on Mono, the open-source implementation of the .NET Framework. Programmers can use UnityScript (a custom language with ECMAScript-inspired syntax), C# or Boo (which has a Python-inspired syntax). Starting with the 3.0 release, Unity ships with a customized version of MonoDevelop for debugging scripts.^[22]
• The Unity Asset Server - A version control solution for all game assets and scripts, using PostgreSql as a backend.
• Audio system built on FMOD library, with ability to play back Ogg Vorbis compressed audio.
• Video playback using Theora codec.^[23]
• A terrain and vegetation engine,^[24] supporting tree billboarding.
• Occlusion Culling with Umbra (only in Unity >= 3.0 Pro).
• Built-in lightmapping and global illumination with Beast (only in Unity >= 3).
• Multiplayer networking using Raknet.
• The Unity Asset Store - An in-editor repository with thousands of Unity-ready assets, including models, characters, code, audio, etc.
• Built-in Pathfinding. Navigation meshes, as they are called, can be utilized in Unity Free, but require the Pro version to be created.^[25]

Version control

The Unity Asset Server was a version control solution for all game assets and scripts.^[26] It is now superseded by the version control system in Unity 3.5. Import settings and other metadata are stored and versioned while updates, commits, and graphical version comparisons are performed inside the Unity Editor. A shortfall with Unity's built-in version control is its lack of support for branching, tagging, or any DVCS features found in modern systems such as Git or Mercurial.
Unity have recently made it possible to use alternative version control software, so larger, more complex projects can be managed using branches or decentralized workflows.^[27]

Licensing

There are two main licenses: Unity and Unity Pro,^[28] with the Pro version being available for a price and the non Pro version being free, although it originally cost around 200 USD. The Pro version has additional features, such as render-to-texture, occlusion culling, global lighting and post-processing effects. The Free version, on the other hand, displays a splash screen (in standalone games) and a watermark (in web games) that cannot be customized or disabled.
Both Unity and Unity Pro include the development environment, tutorials, sample projects and content, support via forum, wiki, and future updates in the same major version (i.e. buying Unity Pro 3.0 gets all future Unity Pro 3.x updates for free).
Unity for iOS and Unity for Android are add-ons to an existing Unity purchase.^[4] A Unity Pro licenses is required to purchase an iOS Pro or Android Pro licenses. The regular Android and iOS licenses can be used with the free version of Unity.
Source code, PS3, Xbox 360, and Wii licenses are negotiated on a case by case basis.^[29]
Educational licenses are provided by Studica with the stipulation that it is for purchase and use by schools, purely for education.^[30]

Future platforms

Linux

Before Linux support was confirmed to be arriving for Unity 4.0, there were numerous stipulations and hints about future Linux support. Specifically, an end-user discovered an option for Linux as a runtime platform in Unity itself^[31] and work on a Linux port was later confirmed by a Unity Technologies developer.^[32] A prototype of a web-plugin for Firefox on Linux was also blogged about on Unity's corporate blog^[33] and another Unity Technologies employee had publicly indicated that work has been done on a Linux port.^[34] Game developer inXile stated that a port exists in an alpha version and will be licensed to provide a Linux version of the upcoming game Wasteland 2.^[35] With the future release of Unity 4.0, Unity will natively support Linux, and can create standalone games for that platform. Unity, however, have stated they do not intend to make a Linux web player at the present time, and the Linux export function, while purported to be functional, is still in Beta, and will likely still be so upon the release of Unity 4.
With support for Flash in Developer Preview,^[15] Linux users are able to play Unity-authored content with a Flash browser plug-in.
As of version 3.5, Unity can publish to Google Native Client,^[36] a form that can be run by any recent version of Google's Chrome browser (including Chrome for Linux).
The upcoming Unity game Wasteland 2 is confirmed to have Linux support, and Unity has given the company a beta version of a Linux export function. Prior to this agreement, the company making Wasteland 2 had wanted to purchase a license to Unity's source code, from which they'd make a port themselves.

Roku 2

On September 28, 2011, it was announced that Unity will provide content for the streaming box top set, Roku 2 through its Union initiative.^[37]

Uses

• Among the Sleep
• Battlestar Galactica Online
• Space Paranoids Online
• Cabals:The Card Game
• Escape Plan
• Family Guy Online
• Fray
• Kerbal Space Program
• Rochard
• Tiger Woods PGA Tour Online^[38]
• Wasteland 2
• Slender (video game)
• City of Steam^[39]