# Physical Sun/Sky

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**Sun Strength:** *Relative strength of the sun's illumination. It is recommended to use a low value (e.g. 0.1) to avoid over-exposure.*

**Sun Rotation:** *Rotation of the sun in the sky relative to the world origin where 0 degrees locates the sun at the positive Y world axis.*

**Sun Elevation:** *Elevation of the sun (in degrees) relative to the horizon.*\
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**Sun/Sky Model:** *Nishita (*[*Nishita et al. 1993.*](http://nishitalab.org/user/nis/cdrom/sig93_nis.pdf)*), Hosek-Wilkie (*[*Hosek-Wilkie et al. 2012.*](https://cgg.mff.cuni.cz/projects/SkylightModelling/HosekWilkie_SkylightModel_SIGGRAPH2012_Preprint.pdf)*), or Hosek-Wilkie (No-Shadow). If the "no-shadow" option is selected, shadow rays from the sun lamp will be disabled.*