Sometimes, as a guy, I look at a picture like this and go, Wow!
The milling approach, which is based on the trochoidal [curve traced by a point on a circle that rolls along a straight line] machining strategies in PowerMILL, has been patented by [German CAM vendor] Iruba. It allows complex “fir-tree” profiles to be produced on milling machines, such as the Hermle C60 five-axis machining centre, rather than having to use specialist broaching [sawtooth] equipment.
The picture show milling small fir-tree geometries on a geared wheel. www.delcam.com