title: Blender - animating simple mesh hierarchy
body: <p>honestly, browsed everywhere I could, but as you might have guessed, failed to find solution to my issue.
  So I need very simple shape to show moving object. By design, it is just moving arrow. Simple, right?
  The catch is that I also need to indicate it's movement speed. By design, it has to be trailing arrows. So something like ">" - standing, ">>" - slowly moving, ">>>" - moving at normal speed, ">>>>" - moving fast.
  Here's my current sketch (it should have 3 sub arrow's in the end).</p>
  
  <p><a href="https://i.stack.imgur.com/rdc0K.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rdc0K.png" alt="arrow"></a>
  So the issue is that i want to make all this states as separate animations, so i can export it as single model and just switch animations as state changes.
  But i can't figure out how to toggle their visibility.
  It seems like there is no way to change state of the child if it is not an armature. I found one trick with vertex groups and masks, but it doesn't work(or maybe i can't figure it out) for miltiple levels, like in my case, when I need each animation to show different sets of subarrows.
  So that's basically the question - how can I : a) animate structure like:
  arrow
   |- speed1
   |- speed2
   |- speed3
  (they all planes);
  b) control visibility of more than 2 vertex groups;
  c) maybe this is just wrong approach and there is proper way to do this.</p>
  
  <p>Thanks for your answers!</p>