In this example, we validate our apparent roughness for light transmitted by a rough GGX microfacet model. Slider on the right of the screen allows to change the roughness of the interface, as well as the refractive index of the top medium and bottom medium. You can compare the approximation method for the apparent roughness using the selector and view either our approximation, Guo et al. [2016], or Kulla and Conty [2017].