title: Three.js: mesh does not receive shadow and is not detected by intersectObjects
body: <p>I have a WebGL Geometry Shape in Three.JS that is made by ExtrudeGeometry.<br>
  My problem is why it doesn't receive shadow (which is powered by THREE.SpotLight) or why Raycaster.intersectObject doesn't detect that!?<br>
  My shape is something like below:  </p>
  
  <pre><code>var geometry = new THREE.ExtrudeGeometry(shape, extrudeSettings);
  var mesh = THREE.SceneUtils.createMultiMaterialObject(geometry, [new THREE.MeshBasicMaterial({ color: color }), new THREE.MeshBasicMaterial({ color: color2, wireframe: true, transparent: false, wireframeLinewidth: 5 })]);
  mesh.position.set(x, y, z);
  mesh.rotation.set(rx, ry, rz);
  mesh.scale.set(s, s, s);
  mesh.castShadow = true;
  mesh.receiveShadow = true;
  scene.add(mesh);
  </code></pre>
  
  <p>It's ExtrudeGeometry natural, or what!?</p>