# Rysunek Roboczy: Krzywa złożona

This page is a translated version of the page Draft BSpline and the translation is 6% complete.
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Draft: Krzywa złożona

Kreślenie → Krzywa złożona
Środowisko pracy
Rysunek Roboczy, Architektura
Domyślny skrót
B S
0.7
Zobacz także
Linia łamana, CubicBezCurve, Krzywa Beziera

## Description

The Draft BSpline command creates a B-spline curve from several points.

The Draft BSpline command specifies the exact points through which the curve will pass. The Draft BezCurve and the Draft CubicBezCurve commands, on the other hand, use control points to define the position and curvature of the spline.

Spline defined by multiple points

## Usage

1. There are several ways to invoke the command:
• Press the button.
• Select the Drafting → B-spline option from the menu.
• Use the keyboard shortcut: B then S.
3. Pick the first point in the 3D view, or type coordinates and press the Enter point button.
4. Pick additional points in the 3D view, or type coordinates and press the Enter point button.
5. Press Esc or the Close button to finish the command.

## Options

The single character keyboard shortcuts available in the task panel can be changed. See Draft Preferences. The shortcuts mentioned here are the default shortcuts.

• To manually enter coordinates enter the X, Y and Z component, and press Enter after each. Or you can press the Enter point button when you have the desired values. It is advisable to move the pointer out of the 3D view before entering coordinates.
• Press R or click the Relative checkbox to toggle relative mode. If relative mode is on, coordinates are relative to the last point, if available, else they are relative to the coordinate system origin.
• Press G or click the Global checkbox to toggle global mode. If global mode is on, coordinates are relative to the global coordinate system, else they are relative to the working plane coordinate system. introduced in version 0.20
• Press L or click the Filled checkbox to toggle filled mode. If filled mode is on, the created spline will have DANEMake Face set to `true` and will have a filled face, provided it is closed and does not self-intersect. Note that a self-intersecting spline with a face will not display properly, for such a spline DANEMake Face must be set to `false`.
• Press T or click the Continue checkbox to toggle continue mode. If continue mode is on, the command will restart after using Finish or Close, or after creating a closed spline by snapping to the first point of the spline, allowing you to continue creating splines.
• Press the Undo button to undo the last point. The Ctrl+Z keyboard shortcut currently does not work.
• Press A or the Finish button to finish the command and leave the spline open.
• Press O or the Close button to finish the command and close the spline. A closed spline can also be created by snapping to the first point of the spline.
• Press W or the Wipe button to delete the curve segments already placed, but keep working from the last point.
• Press U or the button to adjust the current working plane in the orientation defined by the last and the previous point.
• Press S to switch Draft snapping on or off.
• Press Esc or the Close button to finish the command.

## Preferences

• To change the number of decimals used for the input of coordinates: Edit → Preferences... → General → Units → Units settings → Number of decimals.
• To change the initial value of filled mode: Edit → Preferences... → Draft → General settings → Draft tools options → Fill objects with faces whenever possible. Changing the filled mode in a task panel will override this preference for the current FreeCAD session.

## Properties

A Draft BSpline object is derived from a Part Part2DObject and inherits all its properties. It also has the following additional properties:

### Data

Draft

• DANEArea (`Area`): (read-only) specifies the area of the face of the spline. The value will be `0.0` if DANEMake Face if `false` or the face cannot be created.
• DANEClosed (`Bool`): specifies if the spline is closed or not. If the spline is initially open this value is `false`, setting it to `true` will draw a curve segment to close the spline. If the spline is initially closed this value is `true`, setting it to `false` will remove the last curve segment and make the spline open.
• DANEMake Face (`Bool`): specifies if the spline makes a face or not. If it is `true` a face is created, otherwise only the perimeter is considered part of the object. This property only works if DANEClosed is `true` and if the spline does not self-intersect.
• DANEParameterization (`Float`): affects the shape of the spline.
• DANEPoints (`VectorList`): specifies the points of the spline in its local coordinate system.

### View

Draft

• WIDOKArrow Size (`Length`): specifies the size of the symbol displayed at the end of the spline.
• WIDOKArrow Type (`Enumeration`): specifies the type of symbol displayed at the end of the spline, which can be `Dot`, `Circle`, `Arrow`, `Tick` or `Tick-2`.
• WIDOKEnd Arrow (`Bool`): specifies whether to show a symbol at the end of the spline, so it can be used as an annotation line.
• WIDOKPattern (`Enumeration`): specifies the Draft Pattern with which to fill the face of the closed spline. This property only works if DANEMake Face is `true` and if WIDOKDisplay Mode is `Flat Lines`.
• WIDOKPattern Size (`Float`): specifies the size of the Draft Pattern.

## Scripting

To create a Draft BSpline use the `make_bspline` method (introduced in version 0.19) of the Draft module. This method replaces the deprecated `makeBSpline` method.

```bspline = make_bspline(pointslist, closed=False, placement=None, face=None, support=None)
bspline = make_bspline(Part.Wire, closed=False, placement=None, face=None, support=None)
```
• Creates a `bspline` object from the given list of points, `pointslist`.
• Each point in the list is defined by its `FreeCAD.Vector`, with units in millimeters.
• Alternatively, the input can be a `Part.Wire`, from which points are extracted.
• If `closed` is `True`, or if the first and last points are identical, the spline is closed.
• If `placement` is `None` the spline is created at the origin.
• If `face` is `True`, and the spline is closed, the spline will make a face, that is, it will appear filled.

Example:

```import FreeCAD as App
import Draft

doc = App.newDocument()

p1 = App.Vector(0, 0, 0)
p2 = App.Vector(1000, 1000, 0)
p3 = App.Vector(2000, 0, 0)

spline1 = Draft.make_bspline([p1, p2, p3], closed=False)
spline2 = Draft.make_bspline([p1, 2*p3, 1.3*p2], closed=False)
spline3 = Draft.make_bspline([1.3*p3, p1, -1.7*p2], closed=False)

doc.recompute()
```

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