anchor.diff:  
     var bumpMap;
     num bumpScale;
  +
  +  var normalMap = null;
  +  var normalScale;
   
     var specularMap;
   
  
positive.code: 
                         this.bumpMap,
                         this.bumpScale: 1,
  
                         this.combine: MultiplyOperation,
                         this.reflectivity: 1,
  
negative.code:                                  polygonOffsetUnits: polygonOffsetUnits,
                                   alphaTest: alphaTest,
                                   overdraw: overdraw,
                                   visible: visible ) {
                             if (normalScale == null) { normalScale = new Vector2( 1.0, 1.0 ); }
                           }
  
  }
  