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A map of Chiron (the Planet from Alpha Centauri game)

Posted: 17.02.2010, 17:11
by Victor
Here's what I've accomplished so far:

Image
(the original file is 4096x2048)


I made it using in-game screenshots of the original large map (which I first made blank - clear of monoliths, landmarks, colony pods, etc.). I am a Photoshop noob, but I managed to recolour the oceans to make them look a bit more realistic (you don't see so many colours from the orbit) and I also used the liquify tool to make the landmass edges a bit more round.

Just to make sure, this is not meant to look entirely realistic! I am nowhere near the skill level necessary to produce photo-realistic textures. But it doesn't look all that bad, it feels positively alien :) See for yourselves:

Image

Image

(cloud texture isn't mine and I have no idea where I got it from; it's been on my computer for years)
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I am wondering if I should release it or not. After all, Chiron is Firaxis' idea so it's probably protected or something.

Re: A map of Chiron (the Planet from Alpha Centauri game)

Posted: 28.02.2010, 05:55
by Sen
What you have so far looks really nice! The screenshots from Celestia look beautiful...familiar with the blue oceans and white clouds, but alien with the red vegetation. I'm not too familiar with the game, though...I'm assuming the red is plant life? At any rate, it looks really nice.

Re: A map of Chiron (the Planet from Alpha Centauri game)

Posted: 28.02.2010, 09:49
by Victor
The red vegetation is the xenofungus. The game has a really well-developed back story according to which xenofungus covers large swathes of the planet in several meters thick, almost impenetrable mats. The fungal mats form a planet-wide web which is actually a sort of semi-sentient planetary brain (Cameron 'used' the same idea in Avatar :) ).

However Chiron (simply called "Planet" by the colonists) is no paradise. It is larger than Earth and has a 30% stronger surface gravity and 70% denser atmosphere, which unfortunately doesn't contain enough oxygen for humans to be able to breathe comfortably (at sea level, there is just barely enough oxygen in the air). It doesn't matter though because the partial pressure of nitrogen makes the air mildly poisonous - humans without pressure helmets or nitrogen filter masks suffer of nitrogen narcosis similar to that which sometimes affects scuba-divers on Earth. First it's comparable to being mildly drunk, but then you lose consciousness and die. The air also contains various nitrates (which are a product of the native life's strange biochemistry) which break down ozone, so the planet doesn't have any ozone layer to speak of - and the dense troposphere only partially offsets this. (and so on, as I said the back-story is rich :) )

The game files also contain basic information concerning the orbital parameters, rotation periods, moons, etc. of Chiron and other planets. I am trying to make an add-on using this info, but I struggle with the orbital planes and the rotational axis - I need the orbital plane of Chiron to be roughly the same as the orbital plane of the two Alpha Centauri stars (since simulations show this is necessary for the orbits to remain stable), unfortunately in Celestia the orbital plane of the planet is perpendicular to that of the stars. When I tried to align them, I found the planet's rotational axis was totally off, like that of Uranus in our solar sytem. It's kinda frustrating since I don't really understand how Celestia works in this respect so I am doing it in a trial-error manner. Any help here would be appreciated.

Re: A map of Chiron (the Planet from Alpha Centauri game)

Posted: 28.02.2010, 16:37
by Sen
Interesting. It sounds like the designers really wanted to make a realistic setting for their game. I might have to buy it... 8)

Well, for the plane of orbit, Celestia uses the Inclination parameter under EllipticalOrbit. Here is an example (from my own planet around Alpha Centauri A...it has the same "problems" as yours in terms of orbital plane.)

Code: Select all

EllipticalOrbit {   
   Period            1.0000
   SemiMajorAxis     1.0000
   Eccentricity      0.0167
   Inclination       0.0001
   AscendingNode   348.739
   LongOfPericenter 102.947
   MeanLongitude   100.464
}


So, altering the planet's plane of orbit should be as simple as adjusting the inclination value.
As for the planet's axial tilt, this is controlled by the Obliquity parameter under the next setting...see the example. For reference, the Earth's axis is tilted at about 23.4 degrees relative to the orbital plane.


Code: Select all

{
RotationPeriod 1299.367
   Obliquity         10.13
   EquatorAscendingNode 48.42
   RotationOffset 291.20
}


Altering these two values should be able to give you a desirable result. I'll try to work out a test model for you. Meanwhile, do you think you could post your .ssc file?

Re: A map of Chiron (the Planet from Alpha Centauri game)

Posted: 28.02.2010, 17:05
by Sen
Here are the values I have found (by trial and error) that give a fairy nice alignment with Alpha Centauri's orbital plane and the planet's orbital plane, as well as a relatively nice axial tilt. You might need to change the values somewhat to fit your needs though...

Code: Select all

EllipticalOrbit {
      Period            0.5757
      SemiMajorAxis     0.692
      Eccentricity      0.0068
      Inclination       73.2
      AscendingNode     76.681
      LongOfPericenter 131.533
           MeanLongitude    181.979
   }



   RotationPeriod 53.199
   Obliquity         90.13
   EquatorAscendingNode 48.42
   RotationOffset 291.20

Re: A map of Chiron (the Planet from Alpha Centauri game)

Posted: 30.04.2010, 22:26
by mellian
That is pretty awesome. :) I always love the game and the genre. I tried reproducing the map of chiron into high res image before for various diplomacy/rpg games, but none compare.