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Table of Contents
SkyLight shaders
This sub group of shaders are also light sources and can be used with the Sky object
Preetham(SunSky)
Preetham (1999) analytic sky model.
Implements the Preetham et al. sky luminance model via Perez functions (zenithY/x/y + five Perez coefficients per channel). Physically attenuated solar spectrum is computed via Rayleigh scattering, aerosol attenuation, and ozone / water-vapor absorption.
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 Preetham(SunSky) 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).
PragueSkyModel
Prague Sky Model (2021) — dataset-driven full-spectral sky light.
Implements the sky model by Wilkie et al. (2021) and Vévoda et al. (2022), presented in “A Fitted Radiance and Attenuation Model for Realistic Atmospheres”.