Hey kids,

I’ve been working on a banner that involves repulsion physics, after a bit of research, trial and error this is what I came up with. I know it's been done a million times but I thought I'd do it one more ‘cause it’s kind of fun and might be useful to someone in the future. It involves high school physics (remember that thing?).

Anyway, this is the juicy part of the code to be constantly triggered for animation:

//distance between mouse and object on the axis’ 

xDif = this.parent.mouseX - this.x; 

 yDif = this.parent.mouseY - this.y;

//the length of the hypotenuse using Pythagoras

   distance = Math.sqrt(xDif*xDif+yDif*yDif);

//the “magic” number to give us the perfect repulsion

   tempX = this.x-(force/distance)*(xDif/distance);

   tempY = this.y-(force/distance)*(yDif/distance);

//the new coordinates, based on half the distance between current pos and our initial pos  + the magic number

    this.x=(homex-this.x)/2+tempX;

    this.y=(homey-this.y)/2+tempY;

So you also need to instantiate three vars on initalisation:

//these act as an anchor point for the object to return to

private var homex:Number;

private var homey:Number;

//force is the level of repulsion, add or subtract a zero from the end

Private var force:int = 2000;

REPULSION, coming to a banner near you!