Page 1 of 1
Orbit Radius of Moons
Posted: 12.05.2005, 20:21
by Trolls
I'm new to this program and I'm having a bit of trouble setting the correct orbit radius for the moons orbiting my custom planet. I was under the impression the SemiMajorAxis value is what needs to be changed, but despite having different values for each moon, they are all appearing in the same orbit path.
On a related note, how does the value given relate to actual distances in km? For example, if I wanted a moon to have an orbit radius of 300000km, what would I type?
Posted: 12.05.2005, 20:53
by selden
You'll have to provide the text of exactly what you're using in order for anyone to be able to suggest a fix.
You might start by using the SSC orbits of existing moons. See the file Celestia/data/solarsys.ssc for some of them.
The SemiMajorAxis value is in km.
Celestia's "console log" may include an error message. Type a tilde to see it.
Re: Orbit Radius of Moons
Posted: 12.05.2005, 21:02
by t00fri
Trolls wrote:I'm new to this program and I'm having a bit of trouble setting the correct orbit radius for the moons orbiting my custom planet. I was under the impression the SemiMajorAxis value is what needs to be changed, but despite having different values for each moon, they are all appearing in the same orbit path.
On a related note, how does the value given relate to actual distances in km? For example, if I wanted a moon to have an orbit radius of 300000km, what would I type?
To stay with your example: have a look at data/solarsys.ssc under "Moon" "Sol/Earth". You sure know the Earth-Moon distance by heart. So have a look at the entry: "SemiMajorAxis".
That should fix the dimensions for you
Bye Fridger
Posted: 12.05.2005, 21:03
by Trolls
I copied the text from Earth's moon and altered the radius and semimajoraxis values, nothing more. The radius changes seem to be working. Here is the code I've used for a couple of the moons:
Code: Select all
"Aryth" "Ebersun/Eberron"
{
Texture "moon.*"
BumpMap "moonbump.*"
BumpHeight 0.3
Radius 800
# Oblateness 0.002
CustomOrbit "moon"
EllipticalOrbit {
Period 27.321661
SemiMajorAxis 353600
Eccentricity 0.054900
Inclination 5.15
}
Obliquity 23.45 # mean axis
EquatorAscendingNode 0.0 # mean axis
RotationOffset 38
Albedo 0.12
}
"Vult" "Ebersun/Eberron"
{
Texture "moon.*"
BumpMap "moonbump.*"
BumpHeight 0.3
Radius 1440
# Oblateness 0.002
CustomOrbit "moon"
EllipticalOrbit {
Period 27.321661
SemiMajorAxis 403200
Eccentricity 0.054900
Inclination 5.15
}
Obliquity 23.45 # mean axis
EquatorAscendingNode 0.0 # mean axis
RotationOffset 38
Albedo 0.12
}
Posted: 12.05.2005, 21:07
by t00fri
If you could educate me what "Aryth" "Ebersun/Eberron" and "Vult" "Ebersun/Eberron" are and where I can see them with my biiiiiiiiiiiiiiiiiiiiiig telescope, I would be grateful.
Bye Fridger
Posted: 12.05.2005, 21:14
by selden
"CustomOrbit"s are defined internally in Celestia for specific solar system bodies. They override whatever EllipticalOrbit accompanies them.
Delete the CustomOrbit specifications.
Posted: 12.05.2005, 21:19
by Trolls
selden wrote:"CustomOrbit"s are defined internally in Celestia for specific solar system bodies. They override whatever EllipticalOrbit accompanies them.
Delete the CustomOrbit specifications.
Ah ha! Problem solved, thanks
Posted: 12.05.2005, 23:49
by Evil Dr Ganymede
t00fri wrote:If you could educate me what "Aryth" "Ebersun/Eberron" and "Vult" "Ebersun/Eberron" are and where I can see them with my biiiiiiiiiiiiiiiiiiiiiig telescope, I would be grateful.
Bye Fridger
They're fictional. Eberron is a tabletop roleplaying game (based on D&D), these are the moons and its sun.