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Also note that currently only the standard three types of OSL texture filters are supported.

The SIMD version of OSL is optimized to execute 16 samples at a time with Intel® Advanced Vector Extensions 512 (Intel® AVX-512). It can also execute using Intel® Advanced Vector Extensions 2 (Intel® AVX2), Intel® Advanced Vector Extensions (Intel® AVX), or Intel® Streaming SIMD Extensions 4.2 (Intel® SSE4.2) at reduced performance levels.

The SIMD version of OSL supports most all OSL 1.8 language features and library calls , but is incomplete for: dict_find, dict_next, dict_value, setmessage, & getmessage when name!="trace".

RenderMan doesn't support the following OSL features: closures, environment, pointcloud. OSL shaders using incomplete or unsupported features can cause the program to terminate.

OSL patterns currently support many of the features of OSL, but it is important to note that they do not support the use of material closures. Instead the plugin is designed to create pattern results that are subsequently utilized by connecting the OSL outputs to other patterns and also feeding the OSL shader results into the various inputs of Bxdfs and Displace shaders.  Bxdfs and Displace shaders take the place of closures in an extensible way and allow for more complicated layering than the linear combinations provided by OSL closures.

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