There's an indirect way to do just that, but it involves making a brand new compatible raw file & fiddling with values in both the "TerrainColorSchemes.xml" (Threshold ranges, RGB tags, etc) and its sister file "PlanetDescriptions.xml" (Elevation, Potential, ClassRange, etc).
All you'd need is a
lot of patience and full understanding of the 256 greys available (into the raw image) while editing most pixels to represent corresponding features declared in some new
surface types schemas (which also would need adjustments to values based on miscellaneous height fields formatting!). Just darkening the entire pixels grid by a tiny 5% can actually take a whole set of tiles and transform them into some unusable coasts.
(For example; On my currently developping X-Worlds MOD, the Thunderbirds group of five includes 4 similar "Island type" special planets which needed to have a whole set of different "conditions". As a temporary solution, i opted for "
JustRockPlanet" schema in the case of Gordon's planet which made its pseudo-structured tiles layout closer to what i intended to have. And yet, the perfected data still would require other type of personalized schemas to reflect 12 active (Directly ON the island) tiles instead of 14 mostly spread according to the default -justrock- layout. Thus, extensive editing.)
Mind you, this process would be quite tedious... if you want to alter a lot of "pre-defined" planets since such optional settings aren't
really efficient for all the other randomized planet types.
- Zyxpsilon.
