Pixar RenderMan[1] is a photorealistic 3D rendering software produced by Pixar Animation Studios. Pixar uses RenderMan to render their in-house CGI animated movie productions and it is also available as a commercial product licensed to third parties. In 2015, a free non-commercial version of RenderMan became available.[2]

Name

To speed up rendering, Pixar engineers performed experiments with parallel rendering computers using Transputer chips inside a Pixar Image Computer. The name comes from the nickname of a small circuit board (2.5 × 5 inches or 6.4 × 13 cm) containing one Transputer that engineer Jeff Mock could put in his pocket. During that time the Sony Walkman was very popular and Jeff Mock called his portable board Renderman, leading to the software name.[3]

Technology

RenderMan used the RenderMan Interface Specification (RISpec) to define cameras, geometry, materials, and lights. This specification facilitated communication between 3D modeling and animation applications and the render engine that generates the final high-quality (HQ) images. In the past, RenderMan used the Reyes Rendering Architecture. The RenderMan Interface Specification was first presented at SIGGRAPH in 1988.[4] According to Ed Catmull, Pixar developed the interface with a group of about 19 companies, with Pat Hanrahan as the architect.[5] Pixar's commercial implementation of the specification, PhotoRealistic RenderMan (PRMan), was released the following year in 1989.[4] Catmull stated that in 1993, no software product met the RenderMan Standard, and that RenderMan itself met it about two years later.[3]

Additionally RenderMan 21 added support for Open Shading Language to define textural patterns.[6]

When Pixar started development, Steve Jobs described the original goal for RenderMan in 1991:

During this time, Pixar used the C language for developing Renderman, which allowed them to port it to many platforms.[1]

Historically, RenderMan used the Reyes algorithm to render images with added support for advanced effects such as ray tracing and global illumination. Support for Reyes rendering and the RenderMan Shading Language were removed from RenderMan in 2016.[8]

RenderMan 19 had the new RenderMan Integrator System (RIS) and could use Monte Carlo path tracing to generate images.[9] With RenderMan 27, XPU (extreme processing unit) is the main renderer, set to replace RIS (now in maintenance mode).[10]