Draft WireToBSpline

From FreeCAD Documentation

Draft WireToBSpline

Menu location
Modification → Wire to B-spline
Draft, Arch
Default shortcut
Introduced in version
See also
Draft Wire, Draft BSpline


The Draft WireToBSpline command converts Draft Wires to Draft BSplines and vice versa.

Converting a wire to a B-spline, and a closed B-spline to a closed wire


  1. Select a Draft Wire or a Draft BSpline.
  2. There are several ways to invoke the command:
    • Press the Wire to B-spline button.
    • Select the Modification → Wire to B-spline option from the menu.
  3. A new object is created.


  • The command may result in a closed, self-intersecting Draft Wire or Draft BSpline with a face. Such an object will not display properly in the 3D view. Its DataMake Face property, or its DataClosed property, must be set to false.


See also: Autogenerated API documentation and FreeCAD Scripting Basics.

To convert a wire to a B-spline, or vice versa, pass the Points property of the source object to the make_bspline method, or respectively the make_wire method, of the Draft module.


import FreeCAD as App
import Draft

doc = App.newDocument()

p1 = App.Vector(1000, 1000, 0)
p2 = App.Vector(2000, 1000, 0)
p3 = App.Vector(2500, -1000, 0)
p4 = App.Vector(3500, -500, 0)

base_wire = Draft.make_wire([p1, p2, p3, p4])
base_spline = Draft.make_bspline([-p1, -1.3*p2, -1.2*p3, -2.1*p4])

points1 = base_wire.Points
spline_from_wire = Draft.make_bspline(points1)

points2 = base_spline.Points
wire_from_spline = Draft.make_wire(points2)