Make Loader respect transparent property on normal mapped materials.

src/loaders/Loader.js

@@ -420,6 +420,12 @@ THREE.Loader.prototype = {
 			var parameters = { fragmentShader: shader.fragmentShader, vertexShader: shader.vertexShader, uniforms: uniforms, lights: true, fog: true };
 			var material = new THREE.ShaderMaterial( parameters );
 
+			if ( mpars.transparent ) {
+
+				material.transparent = true;
+
+			}
+
 		} else {
 
 			var material = new THREE[ mtype ]( mpars );