Unity is a cross-platformgame engine developed by Unity Technologies, first announced and released in June 2005 at Apple Inc.’s Worldwide Developers Conference as an OS X-exclusive game engine.
As of 2018, the engine has been extended to support 27 platforms.The engine can be used to create both three-dimensional and two-dimensional games as well as simulations for its many platforms. Several major versions of Unity have been released since its launch, with the latest stable version being Unity 2018.2.13, released on October 18, 2018.
The engine has support for the following graphics APIs: Direct3D on Windows and Xbox One; OpenGL on Linux, macOS, and Windows; OpenGL ES on Android and iOS; WebGL on the web; and proprietary APIs on the video game consoles.
Additionally, Unity supports the low-level APIs Metal on iOS and macOS and Vulkan on Android, Linux, and Windows, as well as Direct3D 12 on Windows and Xbox One.
Within 2D games, Unity allows importation of sprites and an advanced 2D world renderer. For 3D games, Unity allows specification of texture compression, mipmaps, and resolution settings for each platform that the game engine supports, and provides support for bump mapping, reflection mapping, parallax mapping, screen space ambient occlusion (SSAO), dynamic shadows using shadow maps, render-to-texture and full-screen post-processing effects.
Since about 2016 Unity also offers cloud-based services to developers, these are presently: Unity Ads, Unity Analytics, Unity Certification, Unity Cloud Build, Unity Everyplay, Unity IAP (“In app purchase” – for the Apple and Google app stores), Unity Multiplayer, Unity Performance Reporting, Unity Collaborate and Unity Hub.
Unity supports the creation of custom vertexes, fragments (or pixels), tessellation, compute shaders and Unity’s own surface shaders using Cg, a modified version of Microsoft’s High-Level Shading Language developed by Nvidia.