alt Hacker NewsVery cool demo, The curve does sort of go screwball when the control points are close together.
After playing with it some more. Not close together, but more side loaded. On reflection while many of these forms would be awkward to find in a drawing program, I think this is the source of the superior spiral the author likes.
It can’t do a loop (or a cusp, in the limit) like cubic Beziers can, and may instead "lock" to a weird hook-like shape, I’m not sure whether it’s just an artifact of the way the demo tries to match the curve to a Bezier.
Loops and cusps are of course not very useful in 2D graphic or typeface design, and even if you’re animating a plane or designing a rollercoaster you’d probably use more than one Bezier to make up a looping shape.