Please see the pictures for a better understanding. The “model” object is a leg, the “body hair” object is a plane with an image texture and an alpha channel.
As you can see the “body hair” is the wrong shape. How do I give it the right shape? Then I just move it a bit and I’ll have the third image almost automatically. At the moment it’s done post prod and manually. Works fine but it’s time consuming and an insult to the thinking man.