hi there i was trying to make an effekt that looks like growing smoldering holes in a paper.

however all methods i tried did not yield satisfying performance results.
the last one i used was a variation on mario klingemanns old as2 effekt (http://www.quasimondo.com/archives/000608.php#000608)

Code:
//the water Sprite to be drwan into a bitmap
var splotches=new Splotches()


var displayMap:BitmapData=new BitmapData(860,520,true,0);
displayMap.draw(splotches);
splotches=null
//
var noiseMap:BitmapData=displayMap.clone();
var tempMap:BitmapData=displayMap.clone();
var zero:Point=new Point(0,0);
var mat:Matrix=new Matrix(1,0,0,1,0,0);
//the visible bitmap
var display:Bitmap=new Bitmap(displayMap);
display.alpha=.9;
addChild(display);

var ct:ColorTransform=new ColorTransform(1,1,1,0.3,0,0,0,0);

var displace:DisplacementMapFilter=new DisplacementMapFilter(noiseMap,zero,1,2,8,8,"color",0xffffff,1);

noiseMap.noise(Math.random() * 0xffffff, 100, 156, 3, false);

function drawWater(e:Event) {
	tempMap.applyFilter( displayMap, displayMap.rect, zero, displace );

	noiseMap.noise(Math.random() * 0xffffff, 100, 156, 3, false);

	displayMap.draw( tempMap, mat, ct, "multiply");

}
addEventListener(Event.ENTER_FRAME,drawWater);
somehow i seem to be missing the point.
i know that bitmap filter on images this large (860x520) are slow but there must be way ?!

thanks for help!