GroIMP sky models fall into two architecturally distinct families.
The Sky node wraps a shader implementing
computeExitance /
computeBSDF. In
Twilight (Sunflow raytracer)
the sky radiance function is sampled continuously per ray. In
GPUFlux it is pre-baked at
scene-build time to a 512×512 importance-sampled environment map
(FluxSkyLight.discritizeSky()) and serialized
to the GPU. Both renderers give physically correct illumination.
The background sky colour is visible in rendered images. Sun
direction is set as a manual direction vector.
| Model | Class | Parameters |
|---|---|---|
| Preetham (1999) |
Preetham
(SunSkyLight)
| turbidity, sun direction |
| Hosek-Wilkie (2012) |
HosekWilkieSkyLight
| turbidity, ground albedo, sun direction |
| Prague Sky Model (2021) |
PragueSkyModelLight
| dataset file, visibility, observer altitude, ground albedo, sun position |