====== HosekWilkieSkyLight ======


 Hosek-Wilkie (2012) analytic sky model.

Implements the Hosek & Wilkie sky luminance model as presented in "An Analytic Model for Full Spectral Sky-Dome Radiance" SIGGRAPH 2012. Compared to the older [[01_user_documentation:05_object:02_light:12_shaders:09_light_shader:01_sunskylight|]] model, Hosek-Wilkie provides better accuracy at low sun elevations and more realistic sunset colouring.

The additional Albedo parameter  controls ground albedo (reflected light contribution).