Dynamic 3d space | Floating Sketches Tutorial

//define number of layer.
var numLayers:uint = 15;
//number of items in a layer
var numBallsPerLayer:uint = 100;
var defaultBallSize:uint = 25;

var stageWidth3d:uint = 800;
var stageHeight3d:uint = 800;

var layers:Array = new Array();
//init
makeMatrix();
//3d created by layers and placing objects on each layer - the layer has it's own distance, simulated by movement and alpha

function makeMatrix():void {
    //walk through desired number of layers
    for (var layerNum:uint=0; layerNum<numLayers; layerNum++){
        //make layer object to add balls to
        var thisLayer:MovieClip = new MovieClip();
        addChild(thisLayer);
        layers.push(thisLayer);
        //create desired number of balls per layer
        for (var ballNum:uint=0; ballNum<numBallsPerLayer; ballNum++){
            //trace("layer: "+layerNum +"; ball: "+ballNum);
            var c1:Number = randomColor();
            var c2:Number = randomColor();
           
            //create ball
            var thisBall:MovieClip = new MovieClip();
            thisBall.graphics.beginFill(c1, .9);
            thisBall.graphics.lineStyle(defaultBallSize/3, c2, .9);
            thisBall.graphics.drawCircle(defaultBallSize, defaultBallSize, defaultBallSize);
            thisBall.graphics.endFill();
           
            //apply filter to ball
            var myGradientGlowFilter = new GradientGlowFilter(0,
                                                  0,
                                                  [c1, c2, c1],
                                                  [0, .9, 1],
                                                  [0, 63, 255],
                                                  20,
                                                  20,
                                                  .9,
                                                  BitmapFilterQuality.HIGH,
                                                  BitmapFilterType.OUTER,
                                                  false);
            var myBlurFilter = new BlurFilter((numLayers-layerNum)/numLayers*5, (numLayers-layerNum)/numLayers*5, 1);
            var filtersArray:Array = new Array(myGradientGlowFilter, myBlurFilter);
            thisBall.filters = filtersArray;
           
            thisLayer.addChild(thisBall);

            //coordinates
            thisBall.x = Math.random() * stageWidth3d * layerNum;
            thisBall.y = Math.random() * stageHeight3d * layerNum;
            //size
            thisBall.scaleY = thisBall.scaleX = layerNum/numLayers * (Math.random() + 1);
           
            //ball animation
            thisBall.layer = layerNum;
            thisBall.addEventListener(Event.ENTER_FRAME, animateBall);
        }
       
        //layer depth/alpha
        thisLayer.alpha = layerNum/numLayers;
       
    }
    //listeners to animate from mouse movement
    addEventListener(Event.ENTER_FRAME, positionLayer);

}

var easingStrength:Number = 10;

function positionLayer(e:Event):void{
    for (var layerNum:uint=0; layerNum<numLayers; layerNum++){
        //move layers according to mouse poosition
        var xv:Number = (stage.stageWidth-layers[layerNum].width)/stage.stageWidth;
        layers[layerNum].x -= (layers[layerNum].x - xv * mouseX) / easingStrength;
        var yv:Number = (stage.stageHeight-layers[layerNum].height)/stage.stageHeight;
        layers[layerNum].y -= (layers[layerNum].y - yv * mouseY) / easingStrength;
    }
}

function animateBall(e:Event):void{
    e.target.x += (Math.random() - .5) * 2 * e.target.layer/numLayers;
    e.target.y += (Math.random() - .5) * 2 * e.target.layer/numLayers;
}

function randomColor():Number{
    return Math.floor(Math.random() * 16777215);
}