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Approximate

In one sentence: Fits a NURBS curve or surface to a set of points, approximating the input within a specified tolerance.

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: Curves → Approximate
Command: Approximate

Unlike Interpolate, Approximate does not require the curve to pass through every point — it minimises the deviation from the point set within the tolerance. This produces smoother curves from noisy data.

Parameters

Parameter Description
Degree min / max Polynomial degree range
Max Segments Maximum number of knot intervals
Continuity Internal continuity at knots: C0, C1, C2
Tolerance Fitting tolerance in mm
Parametrization Chord length, centripetal, or uniform

See also