XYZ File Format and Orbit

General discussion about Celestia that doesn't fit into other forums.
Topic author
rolandd
Posts: 3
Joined: 10.05.2005
With us: 19 years 6 months
Location: Rhode Island

XYZ File Format and Orbit

Post #1by rolandd » 18.05.2005, 20:57

Is the XYZ file format only relative to the sun or can it be relative to any object? For example, I wish to have an object rotate around a planet using an XYZ file.

In addition, using EllipticalOrbit, is it possible to have an object maintain a constant latitute for an orbit other than over the equator? For example, can I have an object rotate in an orbit around one of the poles at a constant latitude?

All The Best,
Roland

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selden
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Post #2by selden » 18.05.2005, 23:37

xyz trajectories are relative to the object being orbited as specified in the SSC file.

For example,

Code: Select all

"spacecraft" "Sol" {
   SampledOrbit "spacecraft.xyz" }

would require a heliocentric trajectory, while

Code: Select all

"spacecraft" "Sol/Earth" {
   SampledOrbit "spacecraft.xyz" }

would require one centered on the Earth.

Elliptical orbits are centered around the center of the body being orbited. You'd have to define an invisible body that's in an orbit around the planet but with an "infinite" orbital period so that it can be placed at an appropriate latitude and not move. Then your object would orbit that body.

See http://www.lepp.cornell.edu/~seb/celest ... s-130.html
for an example (although it has both bodies not moving).


Does this help?
Selden

Topic author
rolandd
Posts: 3
Joined: 10.05.2005
With us: 19 years 6 months
Location: Rhode Island

Post #3by rolandd » 19.05.2005, 14:20

Selden,

Thanks for your direction, this has been very helpful.

Roland


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