Plowing on!
I've put some additional parameters into the planet generator. It's still relatively simple perlin noise based shader but there's a bit of finesse to it. Nothing spectacular though. If anyone is interested, here's roughly how it works.
The land/sea pattern in made from a pair of 3-octave noises. Octave frequencies correspond roughly to continent, country and coastline detail sizes. These frequencies are randomized inside their predefined ranges so each of two noises has a somewhat distinct look. They also have different land/sea threshold values determining the amount of sea vs land area. Thresholds too are chosen randomly.
A third low frequency single octave noise is then used as a mix parameter between the two base noises. Its sample coordinates are un-proportionally scaled, apparently drifting the landmasses in the same direction to a smaller or greater degree.
This is all done to get abrupt changes in the look of the land/sea pattern, to do away with notorious uniformity of pure perlin noise. I might play with this some more in the future, maybe throwing in couple more base noises and some longitude/latitude mapped mixing.
The colors are now somewhat more diverse. The general look is still monochrome and 5 original basic colors are kept (red, orange, cyan, emerald, magenta). However their hues are now slightly shifted by a random amount. The ambient light, which was so far the same bluish/neutral for all planets, is now tinted by a random mid-saturated color. Most of the times this results in a subtle warm/cool contrast between day and night sides of the planet.
