我试过输入THREE.REVISION，控制台会弹出版本的信息，但是我看里面的却是没有定义版本？？？

        var scene = new THREE.Scene();
       var camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 0.1, 1000);
      var renderer = new THREE.WebGLRenderer();
       renderer.setClearColor(0xEEEEEE);
   renderer.setSize(window.innerWidth,window.innerHeight);   
   document.body.appendChild(renderer.domElement);
  var ambientLight = new THREE.AmbientLight( 0xcccccc, 0.4 );
                scene.add( ambientLight );

    var pointLight = new THREE.PointLight( 0xffffff, 0.8 );
                camera.add( pointLight );
                scene.add( camera ); 
                camera.position.z = 5;

             init();
           function init(){
            var onProgress = function ( xhr ) {
                if ( xhr.lengthComputable ) {
            var percentComplete = xhr.loaded / xhr.total * 100;
        console.log( Math.round( percentComplete, 2 ) + '% downloaded' );
                    }
                };
     var onError = function () { };
        new MTLLoader()
        .setPath( 'obj' )
        .load( 'aaa.mtl', function ( materials ) {
        console.log(materials)
        materials.preload();
        new OBJLoader()
        .setMaterials( materials )
        .setPath( 'obj' )
        .load( 'aaa.obj', function ( object ) {
        object.position.y = 0;
        scene.add( object );
        }, onProgress, onError );
                    } );
           }
        function render() {

           requestAnimationFrame(render);
            renderer.render(scene, camera);
            camera.lookAt( scene.position );
        }
        render();

你会不会是文件script：src没加载成功，试试按F12键，打开调试窗口，

并在Console下输入 THREE.REVISION命令，如果没有返回版本号的话，就是因为three.js没加载成功