followShape

Extrude crossSection, but instead of it heading straight up the Z axis, it follows the curve shape. Equivalent to :

followShape(curve, crossSection, /*autoScale*/false, /*convexity*/null)

Extrude profile, but instead of it heading straight up the Z axis, it follows the curve shape.

This required the curve and profile to have their Shape2d.paths available. Therefore you cannot use some types of shapes, such as Union2d.

If autoScale == true, then the profile is scaled such that the final shape's cross section remains the same size. When autoScale == false, the profile is not scaled, which means the final shapes width/thickness will vary depending on the angle at each of curve's vertices.

If the paths with the profile are closed, then the ends are joined to form a torus like shape, otherwise the ends are not joined, and we end up with a sausage shape.

Note, you can follow a 3D path using followPath.