在Three.js中将网格隐藏在透明网格后面

Question

我需要在Three.js中将网格隐藏在透明网格后面。 jsfiddle

var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);

camera.position.set(0, 0, 3);
camera.lookAt(new THREE.Vector3(0, 0, 0));
scene.add(camera);

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

var light = new THREE.DirectionalLight( 0xffffff );
light.position = camera.position;
scene.add(light);

var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

renderer.sortObjects = false;

// Definition 2
var geometry2 = new THREE.SphereGeometry(0.8,32,24);
var material2 = new THREE.MeshLambertMaterial({color: 0xff0000});
var sphere2 = new THREE.Mesh(geometry2, material2);
sphere2.position.set(0,1,0);
// Definition 1
var geometry1 = new THREE.SphereGeometry(1.0,32,24);
var material1 = new THREE.MeshLambertMaterial({color: 0x0000ff, transparent: true, opacity: 0.5});
var sphere1 = new THREE.Mesh(geometry1, material1);

scene.add(sphere2);
scene.add(sphere1);

renderer.render(scene, camera);

因此，红色球体的重叠部分应被透明的蓝色球体image隐藏

有什么解决办法吗？