function binaryTreeWeightingRecursive(arr, start, end, depth) {
  if (start > end) {
    return;
  }
  const mid = Math.floor((start + end) / 2);
  arr[mid] = depth;
  binaryTreeWeightingRecursive(arr, start, mid - 1, depth + 1);
  binaryTreeWeightingRecursive(arr, mid + 1, end, depth + 1);
}
Finds a keyframe node in the traversal

@param {number} megatextureIndex
@returns {KeyframeNode}