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B-Spline to Console

In one sentence: Exports the full definition of a selected B-spline edge — poles, knot vector, weights, and degree — to the Python console as reconstructable code.

Third-party addon — installation required

The Curves workbench is not included in FreeCAD. Install it via Tools → Addon Manager → search "Curves" → Install and restart FreeCAD.

Overview

Workbench: Curves
Menu: Misc. → B-Spline to Console
Command: Curves_bspline_to_console

The output is formatted as Python code that can reconstruct the curve:

import Part
bs = Part.BSplineCurve()
bs.buildFromPolesMultsKnots(
    poles=[...],
    mults=[...],
    knots=[...],
    periodic=False,
    degree=3,
    weights=[...],
    CheckRational=True
)

What is exported

  • Control points — XYZ coordinates of every pole
  • Knot vector — the full non-uniform knot sequence
  • Weights — rational weights (for NURBS)
  • Degree

When to use it

  • Archive a manually designed B-spline for reuse in scripts.
  • Debug a curve that behaves unexpectedly by examining its knot structure.
  • Transfer control point data to an external CAD or analysis application.

See also