Planetary orbit

[willy]

Hey

I am trying to get a prototype of a basic planetary movement system. Something like this:

Black cross: pull object
Blue line planetary movement


The system needs to be able to:
A) Control the strength of the "pull object" (i.e mass).

B1) Has to handle multiple pull objects
B2) Has to handle multiple planets

C) Planet initial speed should have affect on its curved movement.

(D) would be cool if the planets would speed up closer to the pull object and slow down on its way out)

I have no idea how to do this. I've managed to work out A, B2 and C using the direction calculator. But I have to completely rethink this problem if I want to be able to use multiple pull objects. I know there is some brainy math stuff beyond my comprehension here.

Any help would be appreciated, thanks!

[ToxicKiwiGames]

:|
Well you will need to know some pretty advanced physics. I would give a value of gravity for each one, this determins the fall rate of the object going towards the cross.

Then I would simply have a range around the cross that tells it has entered the gravity well. But dont forget that gravity acts over an infinant distance.

Im only doing A Level physics at the moment so i cant help too much, sorry.

[willy]

It doesn't have to be a perfect system. I do want gravity over infinite distances.

I've manged to make a pretty decent system using only the directional calculator, and advanced direction object to calculate distances. It is perfect for my use, but it is not able to handle multiple gravity objects.

Have a look (it's pretty fun to play with)

[Corentin]

I'm pretty sure there are some examples around, maybe even an extension.

But if you want something more precise and easier (once you have learned it) go for box2D or Phyzix extensions.

The strengh of the force is proportionnal to Mass1xMass2/distance²

[willy]

I haven't heard about box2D. I can't find it in the fusionUpdater. Where do I get it?

[Atom]

Box2D is beta at the moment. You can find links to download and info in this forum thread -

http://www.clickteam.com/epicenter/ubbthreads.php?ubb=showflat&Number=155410

[ToxicKiwiGames]

Thats a kick ass example. I was able to make a galaxy with that, thanks

[willy]

Where you able to add more than one point of gravity?

[Burfelt]

While I have no idea about the math required for somethng like this, I do remember Andos from the forum did an example with gravity and planet mass.

http://click.andersriggelsen.dk/readcomment.php?id=28&type=1