internal Overlay( string name )
: base()
{
this.Name = name;
this.scaleX = 1.0f;
this.scaleY = 1.0f;
this.isTransformOutOfDate = true;
this.isTransformUpdated = true;
this.zOrder = 100;
this.isInitialised = false;
rootNode = new SceneNode( null );
}