Sam wrote:Good link here STRESS
But I read
OSL has syntax similar to C, as well as other shading languages. However, it is specifically designed for advanced rendering algorithms and has features such as radiance closures, BSDFs, and deferred ray tracing as first-class concepts.
Its an open shading language for biased materials right?
No if you read the specification you will see it is not since shaders do not output a final colour (as most traditional shading languages do like for example RendermanSL) they output a closure which is basically nothing else than a general term for BRDF, BSDF, BTDF, BSSRDF, or the equivalent for Light sources. It is down to the render itself to do the integration and therefore can use any method it likes biased or unbiased to solve the integration. It even mentions BiDirectional pathtracing and metropolis.
What about unbiased specific settings like complex IOR, thin coat etc.. ?
Maybe its even harder to try to modify OSL for Octane render than writing a complete new shading language

As I can see the language itself doesn't exclude that at all you can have any variable. You might have to add some own closures though, as the language in this version doesn't allow describing closures / integrators in itself.