I’m looking to try to create an effect to show a skill is on cooldown. I’m imaging an effect similar to what happens when a skill is on cooldown in Guild Wars or in League of Legends:

I can figure out how to update the cooldown text, but I’m not sure how to implement the dark mask that gets removed radially over time. I can imagine making it an animation and adjusting the fps as needed but that sounds less than optimal.
Any ideas?
Thanks