I managed to squeeze in two days of development before christmas holidays start. For increased realism I added a framework that translates orbital parameters (semimajor axis, eccentricity, inclination, ..) into 3d positions and was finally able to let the planets move in pseudo-real elliptical orbits around the sun. Currently the eccentricity and inclination and other values are just randomly generated during world building.
On my second day I revisited how planet types are determined. We are still using a zone system that distinguishes between a ‘hot’ zone, a habitable zone and a ‘cold’ zone. I added probability tables for the zones to determine which kind of planet appears with what probability in a given zone. Additionally I added two more planet types: “gas dwarfs” are gas planets but not as big as jupiter and saturn. They can even appear closer to the suns. The other ones are “ice giants” like uranus and neptun. They as well are made up from gases, but heavier ones than Saturn and Jupiter’s.