title: Threejs: PropertyBinding: Cannot parse trackName: .bones[].position
body: <p>Version: THREE.WebGLRenderer 91dev</p>
  
  <p>I'm trying to get a simple animation for a chest opening to work in three.js, but I keep getting the following error when attempting to create an action.</p>
  
  <blockquote>
    <p>PropertyBinding: Cannot parse trackName: .bones[].position</p>
  </blockquote>
  
  <p>The full version of the animation JSON object is here on pastebin: <a href="https://pastebin.com/raw/XH4PBvLQ" rel="nofollow noreferrer">Full JSON String</a>. A short summary is below:</p>
  
  <pre><code>{
      "name": null,
      "fps": 30,
      "length": 0.5333333333333333,
      "hierarchy": [{
                  "parent": -1,
                  "keys": [{
                              "time": 0,
                              "rot": [
                                  0,
                                  0,
                                  0,
                                  1
                              ],
                              "scl": [
                                  1,
                                  1,
                                  1
                              ],
                              "pos": [
                                  0,
                                  0,
                                  0
                              ]
                          },
  </code></pre>
  
  <p>I create an Animation clip with the following commands.</p>
  
  <pre><code>    var clip = THREE.AnimationClip.parseAnimation(animation, armSkeleton.bones);
      geometry.animations.push(clip);
  </code></pre>
  
  <p>The value of clip is as follows:</p>
  
  <pre><code>duration: 0.6
  name: "default"
  tracks: […]
  0: Object {
      name: ".bones[].position",
      times: […],
      values: […],
      …
  }
  1: Object {
      name: ".bones[].quaternion",
      times: […],
      values: […],
      …
  }
  2: Object {
      name: ".bones[].scale",
      times: […],
      values: […],
      …
  }
  3: Object {
      name: ".bones[].position",
      times: […],
      values: […],
      …
  }
  4: Object {
      name: ".bones[].quaternion",
      times: […],
      values: […],
      …
  }
  5: Object {
      name: ".bones[].scale",
      times: […],
      values: […],
      …
  }
  length: 6
  __proto__: Array[]
  uuid: "3E37E10B-74D0-4421-92AF-7A366CF3804F"
  </code></pre>
  
  <p>The problem is when I try and use the clip with:</p>
  
  <pre><code>mixer = new THREE.AnimationMixer(mesh);
  mixer.clipAction(mesh.geometry.animations[0]).play();
  </code></pre>
  
  <p>I get the error that threejs cannot parse the trackname ".bones.position" even though that's the name that the parseAnimation function returns? I'm super confused if anyone can point out something stupid I'm doing I would appreciate it.</p>