load lightMapScale in ObjectLoader.

src/loaders/ObjectLoader.js

@@ -278,6 +278,10 @@ THREE.ObjectLoader.prototype = {
 
 					material.lightMap = getTexture( data.lightMap );
 
+					if ( data.lightMapScale !== undefined ) {
+						material.lightMapScale = data.lightMapScale;
+					}
+
 				}
 
 				if ( data.aoMap !== undefined ) {