Cocos2d Chipmunk gravity question

[AlexGo]

Hi everybody! Just start playing with Cocos2d and Chipmunk and have a question.
I have a simple animation to do in Cocos2d Chipmunk with the tasks:

One round shaped sprite situated in the center of the screen, rigid body type. Center of gravity vector needs to be located in center of this sprite. From different sides of screen (spontaneously and beyond screen size) other rigid round sprites must fall into central sprite to fill visible screen space.
Sprites should not overlap one another. It's like here from 0:12 - http://www.youtube.com/watch?v=2BxkbXfE ... r_embedded

So the question is:
- How to reassign the vector of gravity for all bodies to the center of the screen?

Thanks, colleagues!

[slembcke]

For posterity, original question answered on the Cocos2D forums:
http://www.cocos2d-iphone.org/forum/top ... ost-171187

[AlexGo]

Thank you very much for your patience to newbies, Scott! )