code: function parseJoints (node, parentJointName, accumulator) {
    accumulator = accumulator || {}
    node.forEach(function (joint) {
      accumulator[joint.$.sid] = accumulator[joint.$.sid] || {}
      // The bind pose of the matrix. We don't make use of this right now, but you would
      // use it to render a model in bind pose. Right now we only render the model based on
      // their animated joint positions, so we ignore this bind pose data
      accumulator[joint.$.sid].jointMatrix = joint.matrix[0]._.split(' ').map(Number)
      accumulator[joint.$.sid].parent = parentJointName
      if (joint.node) {
        parseJoints(joint.node, joint.$.sid, accumulator)
      }
    })
  
    return accumulator
  }
docs: Recursively parse child joints