Sketcher CreatePeriodicBSpline: Difference between revisions

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==Limitations== <!--T:7-->
==Limitations== <!--T:7-->


See [[Sketcher_CreateBSpline#Limitations|Sketcher CreateBSpline]].
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* Many types of constraints are not supported at this time. Only the B-spline's control points and knots can be constrained.
* [[Sketcher_Trimming|Trimming]] and [[Sketcher_Extend|extend]] tools are not supported.
* The shape of a B-spline curve can only be edited by dragging one of the control points. The knots lying on the curve cannot be selected.





Revision as of 10:20, 3 June 2023

Sketcher CreatePeriodicBSpline

Menu location
Sketch → Sketcher geometries → Create periodic B-spline
Workbenches
Sketcher
Default shortcut
G B P
Introduced in version
0.17
See also
Sketcher B-spline

Description

This tool traces a periodic (closed) B-spline curve from its control points. (See this page for more info about B-splines.)

A periodic B-spline curve (in white) made from 5 points. Pictured are the control polygon in green (the straight lines connecting the red points), the weight circles in blue and the curvature comb in green. The (3) digit in the centre refers to the degree of the B-spline, and the (1) and (2) digits on the knots lying on the curve refer to their multiplicity.

Usage

  1. Press the Periodic B-spline by control points button.
  2. Create a series of points by clicking in the 3D view. While the command is active, the created points are connected with straight lines, and a construction circle is created centered on each point.
  3. Optionally press D before terminating the input to define the degree of the B-Spline. introduced in version 0.20
  4. Optionally press Backspace before terminating the input to delete the last created control point. introduced in version 0.20
  5. Pick the first curve point, or right-click to terminate the input and generate the curve.
  6. Depending on preferences, the tool may remain active to trace a new curve. Right-click again to exit the command.

Notes

See Sketcher CreateBSpline.

Limitations

See Sketcher CreateBSpline.