Braid v1 — Progressive
A rope caught mid-plait: loose strands feed in, interlace as they cross a fixed braiding front, and scroll away already tied.
The pipes braid from the Flowers family, but being tied rather than existing fully formed. The strands enter as a flat fan of straight tubes and get progressively interlaced at a braiding front that never moves; the tied pattern then scrolls off along the axis while fresh loose material keeps feeding in, so the knot forms at the same spot on screen forever.
There is no geometry in the scene. The whole rope is a signed distance field that the fragment shader sphere-traces per pixel, which is what makes the progressive interlacing cheap: the braid is an equation, so tying it is a term in that equation rather than hundreds of strand objects to move.
