Celestia Forums

Hello everyone. I have a question, wondering if someone can help. Im having a little trouble getting a 3d model positoned right. I cant seem to figure out the orintation line and the other lines that are used for positioning the models. What im trying to do is put a model of a ship in orbit around a star with the side facing the star, and I wanna put another model directly behind the first one in the same position so it looks like its following the other one. could someone explain the lines and what they do or if its not to much trouble maybee give me a example? Ive been changing the numbers around in the orentation line and the assending node line but cant get it right. Thanks

No help, but I'm trying the same thing with two Star Wars models. I could use the same help.

The trouble is, without more detail it's difficult to offer you precise guidance.
MeanAnomaly is probably the parameter you want to change. Define your two objects with the same SemiMajorAxis and Period, ignore all the other parameters, and give one object a MeanAnomaly of zero and the other a very small MeanAnomaly.
Since you haven't told us what orbit definitions you're using, what models you're using, the size of objects you're using, or how far apart you want them to be, there's not much more I can offer.

Grant

I've had loads of probs along these lines and tend to re position the model in Anim8tor to suit the desired effect.

Regards...bh.

Hi,

I have a collection of Spacecraft models @ my site http://homepage.eircom.net/~bcelestia

I tend to use the same method to position the models into an orbit - so
my ssc files are very similar.

step 1: Use Anim8or to orientate the model into the same orientation always. If you open one of my models in anim8or you can see this.

then amend one of my ssc files as follows:

step2: set the desired period and semimajoraxis values.
step3: set the rotationoffset value visually by trial & error to put the ship facing in the correct direction.
step4: adjusting the ArgOfPericenter value, by trial and error, will then achieve the effect you are looking for.

One of my ssc files is shown below:


# Babylon 5 - EAS Tempest

"EAS Tempest" "Eps Eri/Epsilon Eridani 3"
{

Class "spacecraft"
Mesh "EAS Tempest.3ds"
Radius 0.5

EllipticalOrbit {
Period 0.4
SemiMajorAxis 63000
Eccentricity 0.0016886
Inclination 20
AscendingNode 143.1518
ArgOfPericenter 346.2495
MeanAnomaly 13.8216
Epoch 2450700
}

Obliquity 20
RotationOffset -75
EquatorAscendingNode 143.1518
Albedo 0.10
InfoURL "extras/Babylon 5/Info/info_eastempest.html"
}