|Drafting → B-spline|
|Introduced in version|
|Draft Wire, Draft CubicBezCurve, Draft BezCurve|
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
- There are several ways to invoke the command:
- Click the first point in the 3D view, or type coordinates and press the button in the related Line task panel.
- Click additional points in the 3D view, or type coordinates and press the button in the related Line task panel.
- Press or the button in the related Line task panel to finish the command.
- Press or the button to finish the spline, leaving it open.
- Press or the 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 or the button to remove the curve segments already placed, but keep editing the spline from the last point.
- Press or the button to adjust the current working plane in the orientation of the last point.
- Press , or after a point to constrain the next point on the given axis.
- To enter coordinates manually, simply enter the numbers, then press between each X, Y and Z component. You can press the button when you have the desired values to insert the point.
- Press 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 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 DataMake Face
true); if not, the closed spline will not make a face (DataMake Face
false). or click the checkbox to toggle filled mode. If filled mode is on, a closed spline will create a filled face (
- 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
falseto see the spline.
- Hold snapping your point to the nearest snap location, independently of the distance. while drawing to force
- Hold constrain your next point horizontally or vertically in relation to the last one. while drawing to
- Press + or press the button to undo the last point.
- Press or the button to abort the current command; curve segments already placed will remain.
- 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.
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:
- DataArea (
Area): (read-only) specifies the area of the face of the spline. The value will be
0.0if DataMake Face if
falseor the face cannot be created.
- DataClosed (
Bool): specifies if the spline is closed or not. If the spline is initially open this value is
false, setting it to
truewill draw a curve segment to close the spline. If the spline is initially closed this value is
true, setting it to
falsewill remove the last curve segment and make the spline open.
- DataMake Face (
Bool): specifies if the spline makes a face or not. If it is
truea face is created, otherwise only the perimeter is considered part of the object. This property only works if DataClosed is
trueand 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.
- 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 be
- 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 is
trueand if ViewDisplay Mode is
- ViewPattern Size (
Float): specifies the size of the Draft Pattern.
To create a Draft BSpline use the
make_bspline method (introduced in version 0.19) of the Draft module. This method replaces the deprecated
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
bsplineobject from the given list of points,
- 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
True, or if the first and last points are identical, the wire is closed.
Nonethe shape is created at the origin.
True, and the spline is closed, the spline will make a face, that is, it will appear filled.
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()