The Mattepainting Toolkit (gs_mptk) is a plugin suite for Autodesk Maya that helps artists build photorealistic 3D environments with minimal rendering overhead. It offers an extensive toolset for working with digital paintings as well as datasets sourced from photographs.
For Maya versions 2016, version 3.1 of the toolkit adds support for Viewport 2.0, and a number of new features. Version 2.0 is still available for Maya versions 2012-2014. A lite version of the toolkit, The Camera Projection Toolkit (gs_cptk) is available for purchase from the Autodesk Exchange
The Mattepainting Toolkit uses an OpenGL implementation for shader feedback within Maya's viewport. This allows users to work directly with paintings, photos, and image sequences that are mapped onto geometry in an immediate and intuitive way.