Open Shading Language

Open Shading Language (OSL) is a shading language developed by Sony Pictures Imageworks for use in its Arnold Renderer. It is also supported by V-Ray 3, and by the Cycles render engine in Blender (starting with Blender 2.65). OSL's surface and volume shaders define how surfaces or volumes scatter light in a way that allows for importance sampling; thus, it is well suited for physically-based renderers that support ray tracing and global illumination.

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