Sketcher BSplineComb

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Sketcher BSplineComb.svg Sketcher BSplineComb

Menu location
Sketch → Sketcher B-spline tools → Show/hide B-spline curvature comb
Default shortcut
Introduced in version
See also
Sketcher Create B-spline


Shows or hides the display of the Curvature Comb of a B-spline (see this page for more info about B-splines).

The curvature comb indicates the curvature (value of the second-order derivative) of the B-spline at every position. The higher the curvature at a position, the more is the the comb away from the curve. For positive curvatures ("turn to the right"), the comb is at the other side of the curve than for negative curvatures.

Sketcher BSplineCurvatureShow.png

B-spline with a saddle point at its mid position - the curvature comb there is zero.


  1. Select a B-spline
  2. Either use the toolbar button Sketcher BSplineComb.svg Show/hide B-spline curvature comb or use the menu Sketch → Sketcher B-spline tools → Sketcher BSplineComb.svg Show/hide B-spline curvature comb.