UltimateSky

Web Demo
Documentation
UltimateSky intends to model the sky accurately in all its phases. It has a day and night cycle which it models using a calendar and geolocation. The length of day and position of the sun in the sky varies accurately based on the date, latitude and longitude. The model used for the calculations is based on a calendar configuration. The package comes with a standard Earth calendar, one Mars, one Fictional and you can create your custom as well.
In addition to modeling the day night cycle, it renders the stars as seen from earth. The stars are rendered into a cubemap, with data read from a catalogue. It is also possible to provide an modified catalogue, add random stars or mix both solutions.
The skybox can also render two layers of clouds from seamlessly tiling noise textures, for a simple weather effect but its should be noted that in itself this is not intended to be a fullblown weather solution.
In summary, its an easy to use dynamic day and night skybox shader, easy to control control from scripts or left to run on its own. The system is very simple, but has gone trough many iterations to ensure a good quality.
Web Demo