How do I make objects orbit each other?

[MegaPixel]

Hey guys, I'm trying to simulate planetary orbit (it's for physics class)
I was wondering how I could possibly go about doing this..

I've been also looking for a moon prop and all I get is this
[IMG]http://2.bp.blogspot.com/-7QPp0MguyzI/TnT3ESv-LQI/AAAAAAAAAGU/qUdTYpvLDZc/s1600/moon-stares-at-link-in-the-legend-of-zelda-majoras-mask_288x288.jpg[/IMG]

Any suggestions?

[atttapi0]

You probably can't...

[One Ear Ninja]

You could simulate elastics and disable gravity for a prop. That will negate the gravity while the elastics will simulate it.

[editline]12th March 2012[/editline]

Relative to the "sun"

[Balto-the-Wolf-]

[QUOTE=MegaPixel;35115686]Hey guys, I'm trying to simulate planetary orbit (it's for physics class)
I was wondering how I could possibly go about doing this..

I've been also looking for a moon prop and all I get is this
[IMG]http://2.bp.blogspot.com/-7QPp0MguyzI/TnT3ESv-LQI/AAAAAAAAAGU/qUdTYpvLDZc/s1600/moon-stares-at-link-in-the-legend-of-zelda-majoras-mask_288x288.jpg[/IMG]

Any suggestions?[/QUOTE]

Gravitation has a specific formula that could be applied with expression 2 and applyForce. Let me see if I can find it....

,

[img]http://upload.wikimedia.org/wikipedia/en/math/0/f/3/0f36df929ac9d711a8ba8c5658c3bfee.png[/img]
F is the force between the masses,
G is the gravitational constant,
m1 is the first mass,
m2 is the second mass, and
r is the distance between the centers of the masses.

Thanks wikipedia.

That would write out in an e2 as something like this,

Grav=Gravitational Constant*((Moon:mass()*Earth:mass())/(Earth:pos():distance(Moon:pos()))
Moon:applyForce((Earth:pos()-Moon:pos())*Grav)

As to a model, just grab a ball or melon or something and shoot it with a moon-like texture

[Mr. Bix]

or just use that moon

would be awesome

[666]

I haven't tested this but it might work:

[url]http://www.garrysmod.org/downloads/?a=view&id=64330[/url]