为什么JavaScript控制台在渲染函数中没有定义对象？ （three.js所）

Question

这是代码，它在我的浏览器中运行。似乎具有纹理的对象正确呈现，但JavaScript控制台写入 mycylinder 未定义。为什么？我该如何解决这个问题？

var texture,material,mycylinder;
var WIDTH = 400, HEIGHT = 300;
var VIEW_ANGLE = 45, ASPECT =WIDTH/HEIGHT, NEAR=0.1, FAR =10000;

var renderer= new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
var camera= new THREE.PerspectiveCamera(VIEW_ANGLE, window.innerWidth / window.innerHeight, NEAR, FAR);
var scene= new THREE.Scene();

scene.add(camera);
camera.position.set(0,150,400);
camera.lookAt(scene.position);

document.body.appendChild( renderer.domElement );

var light = new THREE.PointLight(0xffffff);
light.position.set(0,250,0);
scene.add(light);

var ambientLight = new THREE.AmbientLight(0x444444);
scene.add(ambientLight);

var cylinderLoader = new THREE.JSONLoader();
cylinderLoader.load( "models/probahenger.js", addModel );

function addModel( geometry, materials ) {

            texture= new THREE.ImageUtils.loadTexture("images/Henger_anyag3.png");
            material= new THREE.MeshLambertMaterial({map: texture});
            mycylinder = new THREE.Mesh( geometry,material);                
            mycylinder.scale.set(30,30,30);
            mycylinder.position.y=0;
            scene.add( mycylinder );

        };

function render() {

        requestAnimationFrame(render);

        mycylinder.rotation.x += 0.01;
        mycylinder.rotation.y += 0.01;

        renderer.render(scene, camera); 
}

render();

Answer 1

当您尝试旋转对象时，很可能尚未加载对象。这应该可以解决问题：

if ( mycylinder !== undefined ) {

    mycylinder.rotation.x += 0.01;
    mycylinder.rotation.y += 0.01;

}