 Improvements include an animation system refresh; a stack-based modifier system; an updated particle system (which can also be used to simulate hair and fur); fluid dynamics; soft-body dynamics; GLSL shaders support in the game engine; advanced UV unwrapping; a fully recoded render pipeline, allowing separate render passes and "render to texture"; node-based material editing and compositing; and projection painting.Part of these developments were fostered by Google's Summer of Code program, in which the Blender Foundation has participated since 2005.Official planning for the next major revision of Blender after the 2.7 series began in the latter half of 2015, with potential targets including a more configurable UI (dubbed "Blender 101"), support for Physically based rendering (PBR) (dubbed EEVEE for "Extra Easy Virtual Environment Engine") to bring improved realtime 3D graphics to the viewport, allowing the use of C++11 and C99 in the codebase, moving to a newer version of OpenGL and dropping support for versions before 3.2, and a possible overhaul of the particle and constraint systems.