/**
   * Interpolates unspecified rot values for objectIndex from start to end.
   *
   * @param objectIndex Index to interpolate.
   * @param startRotIndex Starting rot index.
   * @param endRotIndex Ending rot index.
   */
  private void fillQuats(int objectIndex, int startRotIndex, int endRotIndex) {
    keyframes.get(startRotIndex).look[objectIndex].getRotation(unSyncbeginRot);
    keyframes.get(endRotIndex).look[objectIndex].getRotation(unSyncendRot);
    float startTime = keyframes.get(startRotIndex).time;
    float endTime = keyframes.get(endRotIndex).time;
    float delta = endTime - startTime;
    Quaternion tempQuat = new Quaternion();

    for (int i = startRotIndex + 1; i < endRotIndex; i++) {
      float thisTime = keyframes.get(i).time;
      tempQuat.slerp(unSyncbeginRot, unSyncendRot, (thisTime - startTime) / delta);
      keyframes.get(i).look[objectIndex].setRotationQuaternion(tempQuat);
    }
  }