Unity is an integrated authoring tool for creating 3D video games or other interactive content such as architectural visualizations or real-time 3D animations. Unity is similar to Director, Blender game engine, Virtools or Torque Game Builder in a sense that a graphical environment is the primary way of authoring the game.

Although the editor only runs on Mac OS X, it can produce games for either the Mac or Windows platform. Support for making games for the Wii game console has been announced for 2007.

Unity has a hierarchical, visual editing environment with detailed property inspectors. Assets are created externally, in various 3D modeling, graphics, and audio software. These assets are then imported and assembled into a game using Unity. Although many of the most popular 3D modeling applications are supported by Unity, its integrations with Maya, Cinema 4D, and Cheetah3D are the most complete. Scripting is built on Mono, the open source implementation of the .NET Framework. Because of this, programmers can use JavaScript, C#, or Boo (Python-inspired) syntax.

Unity uses Ageia's PhysX physics engine (version 2.6.2) for dynamics, OpenGL and Direct3D for graphics and OpenAL for sound. Deployment options are Microsoft Windows executable, Mac OS X executable, on the web (via the Unity Web Player plugin for Internet Explorer, Firefox, Safari, Mozilla, Netscape, and Camino), or a Mac OS X Dashboard widget. It is also possible to adapt Unity content as a Mac OS X screen saver. Unity is typically used for rapid development and prototyping. It includes some graphical contents with it. Unity can detect the graphics power available and use lower quality graphics to fall back on when too little power is available.

Unity was a runner-up in the Best OS X Graphics category in the 2006 Apple Design Awards.

Major Features

Integrated development environment

Support for Bumpmapping, Reflection mapping, Parallax mapping and dynamic shadows using shadow maps.

The ShaderLab language for using shaders, supporting shaders written in Cg or GLSL. Render-to-texture and full-screen post processing effects are also supported in the Pro version.

Built-in Support for the PhysX physics engine.

Scripting via Mono.

Automatic asset importing - assets load into Unity and automatically imported, and are re-imported if the asset is updated.

The Unity Asset Server - A full version control solution for all game assets and scripts and optimized for multi-gigabyte projects with thousands of multi-megabyte files.

A terrain and vegetation engine.

Drawbacks

Currently there is no Windows version of Unity's IDE, as the Unity seeks to centre on completing the Unity featureset. A Windows IDE is planned for the future.

Because it is not open-source studios that use Unity are reliant on Unity Technologies to give software updates to keep their games up-to-date with modern features unless they get a source code license.

Unity's IDE has limited tools available for debugging scripts; for example, there is no way to stop execution of scripts in the event of an infinite loop.

Unity is not compatible with some external source control management software.

History

Before commercial release, Unity was in several years in development. Gooball was released in March 2005 with a pre-release version of Unity.

June 2005, Unity 1.0.1 was released.

August 2005, Unity 1.1 release added building games for Windows, C/C++ plugin support and more.

December 2005, Unity 1.2 added image postprocessing effects, ragdolls, blob shadows, built-in first person controller, ability to extend editor with custom scripted wizards and more. Unity 1.2.2 release in March 2006 added support for building Mac Universal Binary games.

June 2006, Unity 1.5 release highlights were web browser plugin for Windows, new character animation system, Universal Binary editor, car physics and lightmap support. 1.5.1 release in September improved support for old graphics hardware and added Unicode support.

November 2006, Unity 1.6 added support for browser-to-game communication, streaming of levels in web games, Windows Vista support and more audio effects.

October 2007, Unity 2.0 added real time dynamic shadows support, the Unity Asset Server, video playback, a terrain engine, a DirectX 9.0 renderer (for Windows games), improved Game GUI creation, and improved Networking with NAT punchthrough.

Full release notes can be found here.

Unity Asset Server

The Unity Asset Server is a full version control solution for all game assets and scripts. The asset server supports multi-gigabyte projects with thousands of multi-megabyte files. Import settings and other metadata are stored and versioned while updates, commits, and graphical version comparisons are all performed inside the Unity Editor. When files are modified, their status is updated instantly. The Unity Asset Server runs on the open source PostgreSQL database server and is available for both Mac OS X and Linux.

Games

Some of the released and in-development games created with Unity are:

GooBall - the first commercial game created with Unity

Big Bang Brain Games, developed by Graveck Interactive and published by Freeverse

MegaPixel, developed by Yogware and released on shockwave.com

Epic Tower Defense, developed by MrJoy and released on shockwave.com

Global Conflicts: Palestine, a serious game on Israeli-Palestine conflict

Tiki Magic Mini Golf, developed by Mondo Robot and published by Freeverse

Splume, online game by Flashbang Studios

Open Fire, a freeware game created with Unity

WolfQuest, a serious game in development by eduweb

shiftcontrol uses Unity for a number of commercial non-game projects

The Late Call a neo-noir stealth game currently in development at ByDesign Games

More projects using Unity can be found in Unity's gallery.

Licensing

There are three main licenses: Unity Indie ($199), Unity Pro ($1499), and the Unity Asset Server ($499). The Pro version has extra features like render-to-texture, postprocessing effects, ability to build standalone Windows games, and the ability to use the Unity Asset Server. Unity Pro is also required for businesses with over $100,000 turnover/year. There is a free 30 day trial of Unity Indie.

Both Indie and Pro licenses include the development environment, tutorials, sample projects and content, support via forum and future updates in the same major version (i.e. buying Unity 2.0 gets all future Unity 2.x updates for free).

Source code and educational licenses can be negotiated on a case by case basis.