Open Shading Language (OSL) is a small but rich language for programmable shading in advanced renderers and other applications, ideal for describing materials, lights, displacement, and pattern generation.

Please read this introduction for an more detailed overview of some of OSL's unique features, description of the current state of the project, and future road map. Also you may download the language specification.

The OSL project includes a complete language specification, a compiler from OSL to an intermediate assembly-like bytecode, a runtime library interpreter that executes the shaders (including just-in-time machine code generation using LLVM), and extensive standard shader function library. These all exist as libraries with straightforward C++ APIs, and so may be easily integrated into existing renderers, compositing packages, image processing tools, or other applications. Additionally, the source code can be easily customized to allow for renderer-specific extensions or alterations, or custom back-ends to translate to GPUs or other special hardware.

OSL was developed by Sony Pictures Imageworks for use in its in-house renderer used for feature film animation and visual effects. The language specification was developed with input by other visual effects and animation studios who also wish to use it.

GitHub

We no longer maintain the SVN repository on Google Code. Instead, you should visit the GitHub project page for OSL: https://github.com/imageworks/OpenShadingLanguage/

Join our Google Groups / Email Lists

• Developers (and for now, all OSL topics): http://groups.google.com/group/osl-dev