使用three.js JSONLoader

只是看不到模型导入到three.js场景中。
几何看起来很好，但无论我申请什么材料，模型都不会显示。

Just can't see models imported into three.js scene. The geometry looks fine but the model isn't displaying no matter what material I apply to it.

我是WebGL的新手，所以对我来说很难诊断，但我的猜测是在JSONLoader回调期间出现问题。

I'm new to WebGL so it's hard for me to diagnose, but my guess is that something is going wrong during the JSONLoader callback.

感谢您的帮助。

var camera, scene, renderer, mesh, loader;

init();
animate();

function init() {

    camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 10000 );
    camera.position.z = 1000;

    scene = new THREE.Scene();

    loader = new THREE.JSONLoader();

    loader.load( "scripts/model.js", function( geometry ) {
        mesh = new THREE.Mesh( geometry, new THREE.MeshNormalMaterial() );
        mesh.scale.set( 10, 10, 10 );
        mesh.position.y = 150;
        mesh.position.x = 0;
    } );

    scene.add( mesh );

    var ambientLight = new THREE.AmbientLight(0x555555);
    scene.add(ambientLight);

    var directionalLight = new THREE.DirectionalLight(0xffffff);
    directionalLight.position.set(1, 1, 1).normalize();
    scene.add(directionalLight);

    renderer = new THREE.WebGLRenderer();
    renderer.setSize( window.innerWidth, window.innerHeight );

    document.body.appendChild( renderer.domElement );

}

function animate() {

    requestAnimationFrame( animate );

    mesh.rotation.x += 0.05;

    renderer.render( scene, camera );
}