Improving my procedural eyebrows. I've made something similar to this before. But it was less precise. This version more accurately keeps the roots of the hairs flush to the surface. And keeps the hair strips oriented to the face the root is connected to. So that when I rotate the individual strips, they remain shapely and pointing outward for maximum visibility.

I was struggling for a couple days, because I didn't realize that when I moved the curves, their normals weren't updating to suit the new orientation of the curves. So I had to figure out how to make the normals of the curve move along with the curve in a consisted way.

The node group isn't perfect yet, but it's getting there. I still have to work a couple more things out, in order to get that perfect eyebrow swoosh shape.