Cublic Spline

open OCADml
open OSCADml

Control points that our cubic spline will pass through.

let control = V2.[ v 0. 10.; v 10. 40.; v 20. 40.; v 30. (-20.); v 40. (-40.) ]

Mark our control points with the debugging helper Debug.show_path2 for reference. We don't really need to number these, so we'll ignore the index parameter and use the same sphere for each point.

let marks = Debug.show_path2 Scad.(fun _ -> color Color.Magenta @@ sphere 2.) control

Fit a cubic spline to the control points, and interpolate fn points along it using the helper Path2.cubic_spline (lower level functions available in the CubicSpline module), then sweep a rectangle along it.

let line =
  let rectangle = Poly2.square ~center:true (v2 2. 5.)
  and path = Path3.of_path2 @@ Path2.cubic_spline ~fn:100 control in
  Scad.of_mesh @@ Mesh.path_extrude ~path rectangle

Union our control point marks and line sweep shapes and output to file.

let () = Scad.to_file "spline.scad" (Scad.add line marks)