<animation type="frame" frame_texture="fly_t">
  <function name="DoAnim" frametime="20" loop="0" alpha="0">
    <frame idx="0" />
    <frame idx="1" />
    <frame idx="2" />
    <frame idx="3" />
    <frame idx="4" />
    <frame idx="3" />
    <frame idx="2" />
    <frame idx="1" />
  </function>
</animation>