导入的 3D 对象不会投射具有三.js的阴影

我目前正在研究三个.js并且我已经通过这三个导入了我在C4D中制作的3D模型。OBJMTLLoader 成功，但我无法让对象投射阴影。我使用了object.castShadow = true，但它不起作用，但我可以在三个中创建几何体.js来投射阴影，所以我知道场景设置正常。

测试场景目前在这里：http://kirkd.co.uk/dev/，现在已经更新了下面建议的修复程序。

代码如下，如果有人可以指出我做错了什么，或者即使导入的对象可以投射阴影，那么我将永远感激不尽。

塔。

        <script>

        var container;
        var controls;
        var camera, scene, renderer;
        var windowHalfX = window.innerWidth / 2;
        var windowHalfY = window.innerHeight / 2;
        init();
        animate();
        function init() {
            container = document.createElement( 'div' );
            document.body.appendChild( container );
            camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 2000);
            camera.position.z = 500;
            camera.position.y = 500;
            scene = new THREE.Scene();
            controls = new THREE.OrbitControls( camera );
            controls.addEventListener( 'change', render );

            var ambientLight = new THREE.AmbientLight(0x0c0c0c);
            scene.add(ambientLight);
            var spotLight = new THREE.SpotLight( 0xffffff );
            spotLight.position.set( 500, 1000, 500 );
            spotLight.castShadow = true;
            spotLight.shadowMapWidth = 1024;
            spotLight.shadowMapHeight = 1024;
            scene.add( spotLight );
            var companion = new THREE.OBJMTLLoader();
            companion.load( 'companion2.obj', 'companion.mtl', function ( object ) {
                object.position.set(0,-20,0);
                object.scale.set( 0.8, 0.8, 0.8 );
                object.castShadow = true;
                scene.add( object );
            });

            var floorGeometry = new THREE.CubeGeometry(1000,4,1000);
            var floorMaterial = new THREE.MeshLambertMaterial({color: 0xff0000});
            var floor = new THREE.Mesh(floorGeometry, floorMaterial);
            floor.position.x=0;
            floor.position.y=-130;
            floor.position.z=0;
            floor.receiveShadow = true;
            scene.add(floor);
            var geometry = new THREE.BoxGeometry( 100, 100, 100 );
            mesh = new THREE.Mesh( geometry);
            scene.add( mesh );
            mesh.position.set(-100,200,10);
            mesh.castShadow = true;
            renderer = new THREE.WebGLRenderer();
            renderer.setClearColor(0xEEEEEE, 1.0);
            renderer.setSize(window.innerWidth, window.innerHeight);
            container.appendChild( renderer.domElement );
            renderer.shadowMapEnabled = true;
            renderer.shadowMapSoft = true;
            spotLight.shadowCameraVisible = true;
            var step=0;
            render();
        };
        function render() {
          camera.lookAt(scene.position);
          renderer.render(scene, camera);
      }

      function animate() {
        requestAnimationFrame( animate );
        render();
    }
    </script>