Draft BSpline
Draft BSpline |
Menu location |
---|
Drafting → B-spline |
Workbenches |
Draft, Arch |
Default shortcut |
B S |
Introduced in version |
0.7 |
See also |
Draft Wire, Draft CubicBezCurve, Draft BezCurve |
Description
The Draft BSpline command creates a B-spline curve from several points. It uses the Draft Linestyle set on the Draft Tray.
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
- There are several ways to invoke the command:
- Press the Draft BSpline button.
- Select the Drafting → B-spline option from the menu.
- Use the keyboard shortcut: B then S.
- Click the first point in the 3D view, or type coordinates and press the Enter point button in the related Line task panel.
- Click additional points in the 3D view, or type coordinates and press the Enter point button in the related Line task panel.
- Press Esc or the Close button in the related Line task panel to finish the command.
Options
- Press A or the Finish button to finish the spline, leaving it open.
- Press O or the Close button to close the spline, that is, a curve will be added from the last point to the first one to form a face. At least three points are required to form a face.
- Press W or the Wipe button to remove the curve segments already placed, but keep editing the spline from the last point.
- Press U or the Set WP button to adjust the current working plane in the orientation of the last point.
- Press X, Y or Z after a point to constrain the next point on the given axis.
- To enter coordinates manually, simply enter the numbers, then press Enter between each X, Y and Z component. You can press the Enter point button when you have the desired values to insert the point.
- Press R or click the checkbox to toggle relative mode. If relative mode is on, the coordinates of the next point are relative to the last one; if not, they are absolute, taken from the origin (0,0,0).
- Press T or click the checkbox to toggle continue mode. If continue mode is on, the BSpline command will restart after you finish the spline, allowing you to draw another one without pressing the command button again.
- Press L or click the checkbox to toggle filled mode. If filled mode is on, a closed spline will create a filled face (DataMake Face
true
); if not, the closed spline will not make a face (DataMake Facefalse
).
- Note: the spline should not be filled if it intersects itself, as it won't create a proper face. If the spline is filled but no shape is visible, manually set DataMake Face to
false
to see the spline.
- Hold Ctrl while drawing to force snapping your point to the nearest snap location, independently of the distance.
- Hold Shift while drawing to constrain your next point horizontally or vertically in relation to the last one.
- Press Ctrl+Z or press the Undo button to undo the last point.
- Press Esc or the Close button to abort the current command; curve segments already placed will remain.
Notes
- A Draft BSpline can be edited with the Draft Edit command.
- A Draft BSpline can be converted to a Draft Wire with the Draft WireToBSpline command.
Properties
See also: Property editor.
A Draft BSpline object is derived from a Part Part2DObject and inherits all its properties. It also has the following additional properties:
Data
- DataArea (
Area
): (read-only) specifies the area of the face of the spline. The value will be0.0
if DataMake Face iffalse
or the face cannot be created. - DataClosed (
Bool
): specifies if the spline is closed or not. If the spline is initially open this value isfalse
, setting it totrue
will draw a curve segment to close the spline. If the spline is initially closed this value istrue
, setting it tofalse
will remove the last curve segment and make the spline open. - DataMake Face (
Bool
): specifies if the spline makes a face or not. If it istrue
a face is created, otherwise only the perimeter is considered part of the object. This property only works if DataClosed istrue
and if the spline does not self-intersect. - DataParameterization (
Float
): affects the shape of the spline. - DataPoints (
VectorList
): specifies the points of the spline in its local coordinate system.
View
- ViewArrow Size (
Length
): specifies the size of the symbol displayed at the end of the spline. - ViewArrow Type (
Enumeration
): specifies the type of symbol displayed at the end of the spline, which can beDot
,Circle
,Arrow
,Tick
orTick-2
. - ViewEnd Arrow (
Bool
): specifies whether to show a symbol at the end of the spline, so it can be used as an annotation line. - ViewPattern (
Enumeration
): specifies the Draft Pattern with which to fill the face of the closed spline. This property only works if DataMake Face istrue
and if ViewDisplay Mode isFlat Lines
. - ViewPattern Size (
Float
): specifies the size of the Draft Pattern.
Scripting
See also: Autogenerated API documentation and FreeCAD Scripting Basics.
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.
- Each point in the list is defined by its
- If
closed
isTrue
, or if the first and last points are identical, the wire is closed. - If
placement
isNone
the shape is created at the origin. - If
face
isTrue
, 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()
- Drafting: Line, Polyline, Fillet, Arc, Arc by 3 points, Circle, Ellipse, Rectangle, Polygon, B-spline, Cubic Bézier curve, Bézier curve, Point, Facebinder, ShapeString, Hatch
- Annotation: Text, Dimension, Label, Annotation styles, Annotation scale
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- Draft Tray: Select plane, Set style, Toggle construction mode, AutoGroup
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- Miscellaneous: Apply current style, Layer, Manage layers, Add a new named group, Move to group, Select group, Add to construction group, Toggle normal/wireframe display, Create working plane proxy, Heal, Show snap toolbar
- Additional: Constraining, Pattern, Preferences, Import Export Preferences, DXF/DWG, SVG, OCA, DAT
- Context menu:
- Layer container: Merge layer duplicates, Add new layer
- Layer: Activate this layer, Select layer contents
- Text: Open hyperlinks
- Wire: Flatten
- Working plane proxy: Write camera position, Write objects state
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