Sketcher CreatePeriodicBSpline: Difference between revisions

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<!--T:10-->
{{Docnav
{{Docnav
|[[Sketcher_CreateBSpline|B-spline]]
|[[Sketcher_CreateBSpline|B-spline by control points]]
|[[Sketcher_CreateBSplineByInterpolation|B-spline by knots]]
|[[Sketcher_CreatePolyline|Polyline]]
|[[Sketcher_Workbench|Sketcher]]
|[[Sketcher_Workbench|Sketcher]]
|IconL=Sketcher_CreateBSpline.svg
|IconL=Sketcher_CreateBSpline.svg
|IconR=Sketcher_CreatePolyline.svg
|IconR=Sketcher_CreateBSplineByInterpolation.svg
|IconC=Workbench_Sketcher.svg
|IconC=Workbench_Sketcher.svg
}}
}}
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|Shortcut={{KEY|G}} {{KEY|B}} {{KEY|P}}
|Shortcut={{KEY|G}} {{KEY|B}} {{KEY|P}}
|Version=0.17
|Version=0.17
|SeeAlso=[[Sketcher_CreateBSpline|Sketcher B-spline]]
|SeeAlso=[[Sketcher_CreateBSpline|Sketcher CreateBSpline]]
}}
}}


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This tool traces a periodic (closed) B-spline curve from its control points. (See [[B-Splines|this page]] for more info about B-splines.)
The [[Image:Sketcher_CreatePeriodicBSpline.svg|24px]] [[Sketcher_CreatePeriodicBSpline|Sketcher CreatePeriodicBSpline]] tool creates a periodic (closed) B-spline curve from control points. See [[B-Splines|this page]] for more information about B-splines.

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[[File:Sketcher Periodic B-spline example01.png|none]]
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<!--T:4-->
{{Caption|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== <!--T:5-->
==Usage== <!--T:5-->

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See also: [[Sketcher_Workbench#Drawing_aids|Drawing aids]].


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# There are several ways to invoke the tool:
# Press the {{Button|[[File:Sketcher_CreatePeriodicBSpline.svg|16px]] [[Sketcher_CreatePeriodicBSpline|Create periodic B-spline]]}} button.
#* Press the {{Button|[[Image:Sketcher_CreatePeriodicBSpline.svg|16px]] [[Sketcher_CreatePeriodicBSpline|Periodic B-spline by control points]]}} button.
# Create a series of points by clicking in the [[3D_view|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.
#* Select the {{MenuCommand|Sketcher → Sketcher geometries → [[Image:Sketcher_CreatePeriodicBSpline.svg|16px]] Create periodic B-spline}} option from the menu.
# Optionally press {{KEY|D}} before terminating the input to define the degree of the B-Spline. {{Version|0.20}}
#* Use the keyboard shortcut: {{KEY|G}} then {{KEY|B}}, then {{KEY|P}}.
# Optionally press {{KEY|Backspace}} before terminating the input to delete the last created control point. {{Version|0.20}}
# For further steps see [[Sketcher_CreateBSpline#Usage|Sketcher CreateBSpline]].
# Pick the first curve point, or right-click to terminate the input and generate the curve.

# Depending on preferences, the tool may remain active to trace a new curve. Right-click again to exit the command.
==Notes== <!--T:14-->
* It is possible to define the weight of the control points by changing the radii of the weight circles. The equality constraints on the circles need to be deleted first. The radius constraint is arbitrary, the weight of the control points will be defined by the relative radii of the circles. It works similar to gravity: the bigger a circle is in relation to the others, the more the curve will be attracted to the control point.

* The visibility of the control polygon, the curvature comb, the degree and the knot multiplicity can be toggled on/off from the [[Sketcher_Workbench#Sketcher_B-spline_tools|B-spline tools]] toolbar.
<!--T:15-->
* Check out the other tools in the [[Sketcher_Workbench#Sketcher_B-spline_tools|B-spline tools]] toolbar for more B-spline editing tools.
See [[Sketcher_CreateBSpline#Notes|Sketcher CreateBSpline]].


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


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<!--T:16-->
See [[Sketcher_CreateBSpline#Limitations|Sketcher CreateBSpline]].
* 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.




<!--T:11-->
<!--T:11-->
{{Docnav
{{Docnav
|[[Sketcher_CreateBSpline|B-spline]]
|[[Sketcher_CreateBSpline|B-spline by control points]]
|[[Sketcher_CreateBSplineByInterpolation|B-spline by knots]]
|[[Sketcher_CreatePolyline|Polyline]]
|[[Sketcher_Workbench|Sketcher]]
|[[Sketcher_Workbench|Sketcher]]
|IconL=Sketcher_CreateBSpline.svg
|IconL=Sketcher_CreateBSpline.svg
|IconR=Sketcher_CreatePolyline.svg
|IconR=Sketcher_CreateBSplineByInterpolation.svg
|IconC=Workbench_Sketcher.svg
|IconC=Workbench_Sketcher.svg
}}
}}

Latest revision as of 09:19, 13 April 2024

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 CreateBSpline

Description

The Sketcher CreatePeriodicBSpline tool creates a periodic (closed) B-spline curve from control points. See this page for more information about B-splines.

Usage

See also: Drawing aids.

  1. There are several ways to invoke the tool:
    • Press the Periodic B-spline by control points button.
    • Select the Sketcher → Sketcher geometries → Create periodic B-spline option from the menu.
    • Use the keyboard shortcut: G then B, then P.
  2. For further steps see Sketcher CreateBSpline.

Notes

See Sketcher CreateBSpline.

Limitations

See Sketcher CreateBSpline.