Extrude-Scale by Function: Ribbons

Alright, one more. This time, the placement and rotation of each extrusion of the base shape (here, a square, but again, it could be any 2-D shape) is controlled by one equation per axis, plus an equation for the scaling, for a total of seven functions you can define any way you like.

This particular shape has no practical application (altho... if we could print pasta?) but does show that OpenSCAD is fully able to make flowing, quasi-organic shapes.

It reminds me of the stuff I used to do, two/three years ago, with TopMod.