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New User Wants to Create Fictional Galaxy

Posted: 13.08.2019, 22:23
by Trismegistus
I am creating a conworld and congalaxy. I wish to use Celestia to simulate the appearance of stars and other celestial bodies in the heavens of these fictional worlds. At this point, I am interested in creating only two solar systems and associated stars in a single galaxy.

I have used the Star Wars mod and find it pretty impressive. I think if I learned more about this, it would probably help me know what I needed to learn further and what to do.

I noticed that the set up for the heavenly bodies for Celestia for the real universe relies on astronomical observations from the earth. In other words, the stars and heavenly bodies are defined in relationship to earth rather than to the center of the Milky Way Galaxy. I wonder if the Star Wars mod has only the center of that galaxy set up in relationship to earth, but all the other bodies established in relationship to the center of the Star Wars Galaxy.

In short, I have a lot of questions. Is there any source or thread that explains about how the Star Wars Galaxy was set up (or any other fictional galaxy)? Thanks a lot.

Posted: 14.08.2019, 13:44
by Janus
The easiest thing to do would be to start over on the data side.
This means using the existing data set as a template, but starting with a blank one.
Remember though, unless you want to declare a lone star as a solar system, it will be based on one of them, not both.

First: Design a solar system, being sure to follow real rules if you want it to look sane, or two, or however many.
This means being sure no two of them come close enough to pull each other out of orbit to start with.
The Earth Venus or Earth Jupiter attraction seems a good rule to use, simply figure out how strong they pull on each other at their closest approach.
Article to read:gravitational factors of the planets
Make sure all of your planets have that or less peak pull on each other, use real numbers not ratios though.
This of course means knowing the masses and orbits of the planets.

Worlds without moons will have almost no tides.
This also effects magnetic fields protecting their atmospheres since moons tend to churn the interiors.
Moons will tend to be tidally locked, meaning only one face showing.
Though having a moon take one or seven years to rotate would have interesting cultural implications.
Multiple moons will affect each other.

Now that you those done, you start by defining important stars, remembering to use only one world as home.
Once you have that step, define your asterisms, constellations, zodiac, etc.

The binary database is then filled with unnamed but numbered stars, which can be generated in mass.
Keep the ratios about the same as ours.

Everything will need textures, and other data.
It is a lot of work, you won't believe how much until you are doing it, and easy to make a mess of, so keep backups at each stage.
That way when you glitch, you roll back start that stage over.

Good luck.


Posted: 17.08.2019, 14:54
by selden

Did you read through the thread here on the forum about the Star Wars Galaxy Addon? It includes a little info about the Addon's development. See viewtopic.php?f=6&t=16057

Inspection of the Addon's files provides a little information. In particular, see the contents of its file README.txt

To answer your question about star placement in the Addon, their positions are all defined using Earth-relative coordinates of RA and Dec. You can see this if you inspect the individual .STC catalog files.

Posted: 19.08.2019, 20:14
by Trismegistus
Thank you for your replies, Janus and Selden. I shall read them more closely in the future when I am free from work.

Tris :smile: