Picture this: The St. Louis Arch with an airplane sitting on it's right outside edge pointing up. The plane rides up the edge and follows that edge across the top and then nose-down on the opposite side. The plane's left wingtip is pointed at you.
That's what I'm trying to do in Motion using an arch and an arrow. I apply the Motion Path to the arrow and use the arch as its path. Then I apply a Snap Alignment to Motion to the arrow as well.
No combination of parameters for the Behaviors or settings in the arrow or arch Properties has allowed me to orientate the arrow properly.
Now imagine the arrow pointing up and you're looking at its flat side. Imagine the arch starting behind the arrow, going up, and then bending back down further away from you in Z-space. You want that arrow to ride that arch up, follow the curve of the arch and come down nose-down on it's opposite side, all the time being perpendicular to the arch.
My goal is to make an arrow that turns back on itself. Well, not directly on itself, but goes in one direction, then loops away from the camera and you see its backside as it goes back toward the edge of the screen from where it began.
You can't do it, Don. Paint strokes (of which the arrow is one) only exist on 2D planes - you can't have them "twist" off of that plane. You could, however, do it with a replicator or emitter though it's a bit tougher to set up.
Freelance Producer/Editor/Motion Graphics Artist
Apple-certified Master Trainer
Author, Motion 4 from Peachpit Press http://www.applemotion.net