Dark Hunter1357 wrote:Tank you now i understand it... And i'm sorry but when i read that in the wiki guide it said:
wikibook wrote:coordinate system associated with the object
Which object ??
The object for which you want to specify an xyz trajectory.
When you define any object in an SSC file for Celestia, you have to specify the coordinate system that you're using to specify its position or orbit. If you don't specify a coordinate system, Celestia assumes Equatorial J2000 centered on the parent object if the parent is a planet or moon,. Ecliptic J2000 if the parent object is the Sun. Celestia v1.5.1 lets you specify any of a multitude of coordinate systems. You need to read Celestia's documentation very carefully to learn about them all.
If you want your spaceship only to travel around one planet, then you should use a coordinate system centered on that planet.
If you want your spaceship to travel between planets, then you should use a coordinate system centered either on the Sun or on the Solar System Barycenter.
Is there anyway of finding out what are the x,y,z position of an object associated whit the object my spaceship is orbiting ?
Yes.
If it's an imaginary planet that you created yourself, you'll have to write a Lua (CELX) script and call the function getposition. (Ask for help in the scripting Forum if you need it.)
If it's a real planet in our solar system, you can either use a CelX script or you can ask the JPL Horizons ephemeris server.
But, again, you also need to specify which coordinate system the xyz position should be provided in:
one centered on the Sun, one centered on the Solar System Barycenter, one centered on the planet, etc.
The Ecliptic J2000 coordinate system centered on the Solar System Barycenter probably would be the easiest to use in Celestia . It's often called the "universal coordinate system" in Celestia's documentation.