iray rendering engine, which added GPU acceleration to the product. In 2013, the ambient occlusion pass was also accelerated by CUDA, and in 2015 the GI Next engine was added which can be used to compute all indirect/global illumination on GPUs. In 2003, Mental Images received an Academy Award for contributions of mental ray to motion pictures. See also Dielectric Shader, able to realistically render the behavior of light rays passing through materials with differing refractive indices. PhotoWorks (ray tracing software), previously part of SolidWorks which used a version of the Mental Ray rendering engine as its renderer in older versions. Notes Further reading Driemeyer, Thomas: Rendering with mental ray, SpringerWienNewYork, Driemeyer, Thomas: Programming mental ray, SpringerWienNewYork, Kopra, Andy: Writing mental ray Shaders: A perceptual introduction, SpringerWienNewYork, External links Mental Ray home page Global illumination software Rendering systems 3D rendering software for Linux Proprietary freeware for Linux