The source of the demo used to showcase the GodRayPlane class in the Starling Wiki.

Demo_GodRayPlane.as

package
{
    import flash.geom.Point;
    import flash.ui.Keyboard;

    import starling.core.Starling;
    import starling.display.DisplayObjectContainer;
    import starling.display.Image;
    import starling.events.KeyboardEvent;
    import starling.events.Touch;
    import starling.events.TouchEvent;
    import starling.events.TouchPhase;
    import starling.extensions.GodRayPlane;
    import starling.textures.Texture;

    public class Demo_GodRayPlane extends DisplayObjectContainer
    {
        [Embed(source="../assets/water.jpg")]
        private static const BackgroundAsset:Class;

        private var _godRays:GodRayPlane;

        public function Demo_GodRayPlane()
        {
            var background:Image = new Image(Texture.fromEmbeddedAsset(BackgroundAsset));
            addChild(background);

            _godRays = new GodRayPlane(background.width, background.height);
            _godRays.speed = 0.1;
            _godRays.fade = 1;
            _godRays.size = 0.065;
            _godRays.shear = 0.5;
            _godRays.skew = -0.26;
            _godRays.contrast = 2;

            addChild(_godRays);

            Starling.juggler.add(_godRays);

            addEventListener(TouchEvent.TOUCH, onTouch);
            Starling.current.stage.addEventListener(KeyboardEvent.KEY_UP, onKey);
        }

        private var _testProperty:String = "skew";

        private function onKey(event:KeyboardEvent, keyCode:uint):void
        {
            switch (keyCode)
            {
                case Keyboard.P: _testProperty = "speed"; break;
                case Keyboard.I: _testProperty = "size"; break;
                case Keyboard.K: _testProperty = "skew"; break;
                case Keyboard.H: _testProperty = "shear"; break;
                case Keyboard.F: _testProperty = "fade"; break;
                case Keyboard.C: _testProperty = "contrast"; break;
            }

            trace("now modifying " + _testProperty);
        }

        private function onTouch(event:TouchEvent):void
        {
            var touch:Touch = event.getTouch(this, TouchPhase.MOVED);
            if (touch)
            {
                var movement:Point = touch.getMovement(this);
                var delta:Number = movement.x / 200;

                _godRays[_testProperty] += delta;

                trace("godRays." + _testProperty + " = " + _godRays[_testProperty]);
            }
        }
    }
}