Implemented "rings winter" effect on Saturn (don't know if this effect has some name, "rings winter" is my invention). It is a well known effect of winter hemisphere became blue as if receives a rings shadow. This is because there become too cold for a methane haze which makes Saturn look yellowish. The atmosphere became clear and cloudless and we see just a clear blue air, like on Uranus and Neptune.



The system is completely integrated into engine. New variables were introduced for surface and cloud layers and for rings to control the effect, which are:
- integrated into planet scripts to use with catalog planets;
- procedurally generated for procedural gas giants and cold planets;
- integrated into the planet editor.