Oolite Bulletins

@another_commander
There is texture 8k_earth_diffuse2.png in pack. Just as alternative variant of 8k_earth_diffuse.png or it has some function?
And sorry for off-topic - I have questions about planetinfo.plist in general.
There is parameter land_fraction in game planetinfo.plist. I can’t find it on EliteWiki planetinfo.plist page, but I find percent_land parameter. Seems the only difference between land_fraction and percent_land is data format: land fraction in range from 0.0 to 1.0, percent_land in range from 0 to 100, right? Or there are other differences I missed?
I can’t find in game planetinfo.plist percent_ice parameter, described on EliteWiki page. Is it omitted intentionally? So I can use it as optional parameter?
And can I control size of polar region (polar_land_color, polar_sea_color, polar_cloud_color) or it is hardcoded ratio?

stranger wrote: ↑Thu Sep 24, 2020 11:40 pm

There is texture 8k_earth_diffuse2.png in pack. Just as alternative variant of 8k_earth_diffuse.png or it has some function?

Just an alternative variant, an easter egg, if you wish. That texture is from Solar System Scope.

There is parameter land_fraction in game planetinfo.plist. I can’t find it on EliteWiki planetinfo.plist page, but I find percent_land parameter. Seems the only difference between land_fraction and percent_land is data format: land fraction in range from 0.0 to 1.0, percent_land in range from 0 to 100, right? Or there are other differences I missed?

This is correct. Or at least should be. Planetinfo has changed a lot throughout the years and by more than one developers, to the point where I am not sure that everything in there works as advertised anymore. The best advice I can offer is to try and see what works best for you.

I can’t find in game planetinfo.plist percent_ice parameter, described on EliteWiki page. Is it omitted intentionally? So I can use it as optional parameter?

No idea what the status of this property is. Please do try it and let us know if it works OK.

And can I control size of polar region (polar_land_color, polar_sea_color, polar_cloud_color) or it is hardcoded ratio?

I will have to check and get back to you on that.

Thank you!
I'll try and report results.

another_commander wrote: ↑Fri Sep 25, 2020 6:50 am

And can I control size of polar region (polar_land_color, polar_sea_color, polar_cloud_color) or it is hardcoded ratio?

I will have to check and get back to you on that.

OK, I did a few tests and it seems that the key polar_fraction, which could in theory be doing what you want, does not. At least not in a visible way. It seems that it is used in calculations for determining the specular value of polar areas when constructing the internal specular map and that's it. Also, it seems that the term polar is used quite loosely here, since the effects of polar_land_color, polar_sea_color and polar_cloud_color appear to spread well beyond polar zones. To test that, try setting these values to "0 0 1", "0 1 0" and "1 0 0" and see how the three base colors spread across the entire planet.

In general, there are a lot of very complex calculations going on when generating the planet textures, with some variable names seemingly not being closely related to their actual functionality. The truth is that I am not too familiar with them though, so I might be simply getting something very wrong here. Anyway, if you feel brave enough to dive in and try to figure the complexity out, you want to have a look at the OOPlanetTextureGenerator.m source code file.

@another_commander
I'm not ready to dive so deep yet.
Testing cloud_fraction and land_fraction. No noticeable visual effects on F7 screen.
percent_cloud, percent_ice and percent_land works. percent_ice seems generates too small polar caps if it is set close to zero, but at least it works. Maybe I'll try later to look source code just for curiosity.

another_commander wrote: ↑Tue Sep 29, 2020 7:04 am

Also, it seems that the term polar is used quite loosely here, since the effects of polar_land_color, polar_sea_color and polar_cloud_color appear to spread well beyond polar zones. To test that, try setting these values to "0 0 1", "0 1 0" and "1 0 0" and see how the three base colors spread across the entire planet.

Interesting! Looks as polar_land_color actually control color of polar regions AND highlands. So it can be used to simulate mountain glaciers in cold worlds and mountain steppes (dry grasslands) in tropical worlds. Thank you for this observation!

UPD
percent_land works in not obvious way too. Setting percent_land to 25, get archipelago of small islands in vast ocean. Setting percent_land to 75, get supercontinent with isolated small lakes.
Maybe I'm wrong but it looks like percent_land actually set sea level in range from lowest to highest terrain elevation, not land/sea ratio.