OnDocumentMouseMove Three.js 不起作用

我对three.js完全没有经验，但我正在尝试创建一种与此相同的相机效果：https ://threejs.org/examples/#webgl_geometry_colors

我试图使用以下代码读出鼠标位置并应用它们（在示例中它们以相同的方式执行）。为了找出问题出在哪里，我输入了“camera.positon.x = 1000”以查看它是否有效，但它无效。现在我不知道问题出在哪里，但我就是无法让鼠标工作。

function onDocumentMouseMove( event ) {
    mouseX = ( event.clientX - windowHalfX );
    mouseY = ( event.clientY - windowHalfY );
    camera.position.x = 10000;
}   

（顺便说一下，我不想使用轨道控制）提前致谢

下面是整个代码

<script>

    var renderer, camera, controls, scene, mesh1, mesh2;

function init(){
    renderer = new THREE.WebGLRenderer({canvas: document.getElementById('myCanvas'), antialias: true});   
    renderer.setClearColor(0x000044);        

    scene = new THREE.Scene();        
    camera = new THREE.PerspectiveCamera(15, window.innerWidth/window.innerHeight, 0.1, 3000);    
    camera.position.set(0,0,750);        

    resize();
    window.onresize = resize;

    var light = new THREE.AmbientLight(0xFFFFFF, 0.9);
    scene.add(light);

    var light2 = new THREE.PointLight(0xFFFFFF, 1);
    scene.add(light2);
    light2.position.set(0,8,75);

    var geometry = new THREE.BoxGeometry(30, 30, 1);
    var material = new THREE.MeshPhongMaterial({
        color: 0xFF1111,
    });
    mesh1 = new THREE.Mesh(geometry,material);
    mesh1.rotation.x = -0.05;

    scene.add(mesh1);
    mesh1.position.set(0,0,50);

    var geometry = new THREE.BoxGeometry(30, 30, 1);
    var material = new THREE.MeshPhongMaterial({
        color: 0x11FF11,
    });
    mesh2 = new THREE.Mesh(geometry,material);
    mesh2.rotation.x = -0.05;

    scene.add(mesh2);
    mesh2.position.set(0,0,0);

    var geometry = new THREE.BoxGeometry(30, 30, 1);
    var material = new THREE.MeshPhongMaterial({
        color: 0x1111FF,
    });
    mesh3 = new THREE.Mesh(geometry,material);
    mesh3.rotation.x = -0.05;

    scene.add(mesh3);
    mesh3.position.set(0,0, -50);

    document.addEventListener( 'mousemove', onDocumentMouseMove, false );
}

function resize() {
    renderer.setSize(window.innerWidth, window.innerHeight);
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
}

function onDocumentMouseMove( event ) {
    mouseX = ( event.clientX - windowHalfX );
    mouseY = ( event.clientY - windowHalfY );
    camera.position.x = 10000;
}    

function render() {    
    requestAnimationFrame( render );
    renderer.render( scene, camera );
    camera.position.x += 0.5;
    camera.lookAt(new THREE.Vector3(0, 0, 0));
}

init(); render();    

</script>