anchor.diff:  
     TestGLTFScene(Camera camera) : super(camera);
   
  -
  +  List _meshes = [];  
  +  
     @override
     void enter() {
   
  -//    camera.position.setValues(-20.0, 2600.0, 1000.0);
  +    //    camera.position.setValues(-20.0, 2600.0, 1000.0);
       camera.position.setValues(100.0, 100.0, 300.0);
       camera.lookAt(new Vector3.zero());
   
  -    var url = "../models/duck/duck.json";
  -//    url = "../models/SuperMurdoch/SuperMurdoch.json";
  -//    url = "../models/rambler/rambler.json";
  -    
  -    var loader = new GltfLoader2();
  -    loader.load(graphicsDevice.ctx, url).then((nodes) {
  -      nodes.forEach((node) {
  -        add(node);
  -      });
  +    var urls = ["../models/duck/duck.json", "../models/SuperMurdoch/SuperMurdoch.json", "../models/rambler/rambler.json", "../models/wine/wine.json"];
  +
  +    var selector = new SelectElement();
  +    urls.forEach((u) {
  +      var option = new OptionElement(data: u.split("/").last, value: u);
  +      selector.children.add(option);
  +      
       });
  +    selector.onChange.listen((e) {
  +      var opt = selector.options[selector.selectedIndex];
  +      _loadModel(opt.value);
  +    });
  +    querySelector("#controllers").children.add(selector);
  +
  +    _loadModel(urls.first);
   
       var light0 = new PointLight(0xffffff);
       light0.intensity = 0.9;
  
positive.code:     light1.direction = new Vector3(-1.0, -1.0, 0.0).normalize();
      add(light1);
    }
    
    @override
    void enterFrame(num elapsed, num interval) {
    }
  
negative.code: import 'package:orange/orange.dart';
  import 'package:vector_math/vector_math.dart';
  import 'dart:html';
  
  
  
  