$ .getJSON数据已绑定，但在界面上不可见

Question

我需要绑定事件下拉菜单。我能够将数据成功绑定到选择标签中。但是数据在下拉列表中不可见。我可以在chrome的检查工具中看到这些值。值已加载。我不知道我在想什么。

        var loader = new THREE.GLTFLoader(); /* Creates a GLTF Loader */


        loader.load( 'https://api.codetabs.com/v1/proxy?quest=https://www.adambeddall.com/monkey.glb', function ( gltf ) { /* Path to model */
            scene.add( gltf.scene ); /* Adds the model to the scene */
            model = gltf.scene
        });

        var plane = new THREE.Plane(new THREE.Vector3(0, 0, 1), -4);
        var raycaster = new THREE.Raycaster();
        var mouse = new THREE.Vector2();
        var pointOfIntersection = new THREE.Vector3();
        canvas.addEventListener("mousemove", onMouseMove, false);

        function onMouseMove(event){
          mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
            mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;
          raycaster.setFromCamera(mouse, camera);
          raycaster.ray.intersectPlane(plane, pointOfIntersection);
          model.lookAt(pointOfIntersection);
        }

因此，我所需要做的就是显示不可见的数据（不确定原因）。任何帮助将不胜感激。