import flash.display.BitmapData;
import flash.filters.ConvolutionFilter;
 
Stage.scaleMode = "noScale";
 
var myBitmapData:BitmapData = new BitmapData(510, 290, true, 0);
 
var mc:MovieClip = this.createEmptyMovieClip("mc", this.getNextHighestDepth());
mc.attachBitmap(myBitmapData, this.getNextHighestDepth());
 
var matrixX:Number = 3;
var matrixY:Number = 3;
var matrix:Array = [2, 2, 2, 2, 4, 2, 2, 2, 2];
var divisor:Number = 16;
     
var filter:ConvolutionFilter = new ConvolutionFilter(matrixX, matrixY, matrix, divisor);
 
var increment:Number = 0;
setInterval (neige, 30);
function neige()
{
	myBitmapData.noise(increment++, 0, 255, 1, true);
	myBitmapData.applyFilter(myBitmapData, myBitmapData.rectangle, new Point(0, 0), filter);
}

mc.alpha=50;