bitmapData.noise: any way to control speed of change?

[saratogacoach]

Hi,

Moved to ActionScript 3 section

I have beginner skills using AS3 and have been trying to improve a basic movie that generates a visual noise pattern. I need it for an eLearning lesson.

A while back, I got some help pulling this script together. It uses bitmapData.noise to generate a visual noise pattern. It can be viewed here:

http://www.eLearningprojects.com/WN1.html

I checked with a colleague who is expert on the use of these visual patterns, and he suggested that the change speed is too fast: that the dots (pixels) need to change at just under 400 dots per second for an 800 x 600 stage.

I tried changing the "seed" parameter, but while this slowed down the pixel-dot change, it did not run smoothly.

I'm not sure what else can be scripted to accomplish slowing down the change rate and would appreciate any help.

I will attach the AS3, which is currently in the first keyframe.

var array:Array=new Array();
for (var i:uint = 0; i < 255; i++) {
array[i] = 0xffffff * (i % 2);
}
var _bitmapData:BitmapData;
var bDHolder:Sprite = new Sprite();
_bitmapData = new BitmapData(stage.stageWidth/4, stage.stageHeight/4);

bDHolder.addChild(new Bitmap(_bitmapData));
bDHolder.scaleX = bDHolder.scaleY = 4; 

addChild(bDHolder); 

addEventListener(Event.ENTER_FRAME, onSpriteEnterFrame);

function makeNoise():void {
            _bitmapData.noise(getTimer(), 100, 255, 7, true);
            _bitmapData.paletteMap(_bitmapData, _bitmapData.rect, new Point(0,0), array, array,array);
} 

function onSpriteEnterFrame(event:Event):void {
            makeNoise();
}

var itsNoisy:Boolean = true; 

stage.addEventListener(MouseEvent.MOUSE_DOWN, manageNoise); 

function manageNoise(evt:MouseEvent):void {
     if(itsNoisy){
         removeEventListener(Event.ENTER_FRAME, onSpriteEnterFrame)
     } else {
         addEventListener(Event.ENTER_FRAME, onSpriteEnterFrame)
     }
     itsNoisy = !itsNoisy;
}

Thanks in advance for your help.

Kind Regards,

saratogacoach