Animate a string of arrows

[janetl51368789]

I need to show water flow in a river system. Each of the 8 branches would have up to ten arrows following each other. I am not very advanced in After Effects but can animate single arrows. Ideally the arrows might look like this . Can someone help and explain in very easy terms?

Many thanks in advance.

[Rick Gerard]

The easiest way to animate a string of graphics (arrows) is to move them along a path until the second arrow gets to the same position as the first arrow. When the distance moved is perfect, set an outpoint at that keyframe for the layer, Pre-compose, move all attributes to the new comp, and trim to the layer length. Then, apply Time Remapping to the nested pre-comp. This will give you a keyframe at the first frame and one at the end of the last frame. If you move to the last keyframe, the screen will go blank because the keyframe is after the layer ends.

Move back one from the last Time Remapping Keyframe, add a new keyframe, and then delete the last keyframe. You should now see arrows at the first and last keyframes.

The last step is to add a simple loopOut() expression to time remapping. It will now appear that all arrows are constantly moving. 

You can stack the arrows individually or put them all on the same shape layer by simply copying and pasting. You can also use the Echo effect to generate a string of moving arrows. If you have already created an arrow that moves along a curved path, just duplicate the layer and offset the timing enough to create your evenly-spaced arrows. Pre-compose, then use the move exactly one position trick to set up your loop.

[janetl51368789]

WOW! Thank you for the very quick response. Despite your clear instructions, I'm still not sure how to do this. My drawing was misleading in that what I want is to have a single ediutable path (in AE) that I can lay a few individual arrows on. 

Your solution seems like I will need to move the string of arrows as a whole, one arrow at a time. Am I correct?

Can I then easily edit the path in AE?

I know I'm asking quite a lot but could you demonstrate this?

[Rick Gerard]

I don't have time to do a tutorial, but I did create a project file for you that shows how I would use Arrows from a text layer and also how I would use Trim Paths and taper to create a moving arrow, apply Echo, find a looping point in the timeline, then trim and pre-compose the trimmed layer to use time remapping and loopOut().

I hope that is enough to get you started. 

Note: The GIF's frame rate makes the yellow arrows look like they are moving backward, but in the Comp, they move in the right direction. I hope this helps.

[janetl51368789]

YES, that looks exactly what I need. Now, I'll try to figure out how to make it my self. Thank you! By-the-way, in my searching the web for solutions, your name comes up frequently helping and guiding .