[away3d] Why can't use addChild in a MovieMaterial ?

[juliancruz87]

I try to use addChild in my MovieClip but doesn't work

private function material():MovieMaterial
                {
                        var mc:MovieClip = new WorldMaterial();  //movieclip 
inside the
library flash.
                        var objectMap:ObjectMap = new ObjectMap("newMap"); // 
Class extends
MovieClip
                        objectMap.graphics.beginFill(0x000000);
                        objectMap.graphics.drawCircle(0,0,500);
                        objectMap.graphics.endFill();
                        mc.addChild(objectMap);
                        var sp:Sprite = new Sprite();
                        sp.addChild(mc);
                        worldMat = new MovieMaterial(sp);
                        return worldMat
                }

private function initWolrd():void
{
var div:int = 35;
// this line create the world
world = new Sphere({segmentsH:div,segmentsW:div,radius:
80,material:material()});
scene.addChild(world);
}


I can't add child if the movieclip is inside the flash library ????