three.js加载obj模型网页控制台报错?报错

用three.js框架加载外部OBJ模型时网页控制台报了一个我不太理解的错误

我使用的浏览器是谷歌浏览器
代码如下：

        var loader = new THREE.OBJLoader();

        loader.load("model/file2.obj",function (loadedMesh) {

            var material = new THREE.MeshLambertMaterial({color: 0x5C3A21});

 

            loadedMesh.children.forEach(function (child) {

                child.material = material;

                child.geometry.computeFaceNormals();

                child.geometry.computeVertexNormals();

            });