|Расположение в меню|
|Черчение → Кривая Безье|
|Представлено в версии|
The BezCurve tool curve uses control points to define the direction of the curve; on the other hand the Draft BSpline tool specifies the exact points through which the curve will go. To create exact circular or elliptical curves, use Draft Arc and Draft Ellipse.
Bezier curve defined by multiple control points
- Invoke the Draft BezCurve command several ways:
- Press the button in Draft toolbar
- Press the then keyboard keys
- Use the Draft → Bezier tools → BezCurve entry in the Draft menu
- Click a first point on the 3D view, or type a coordinate and press the button.
- Click additional points on the 3D view, or type a coordinate and press the button.
- Press or the button, or double-click the last point to complete the edition.
Объект создается как одна кривая Безье степени (number_of_points - 1). Это можно изменить на кусочную кривую Безье определенной степени после создания с помощью properties editor. Кривые Безье можно редактировать с помощью .
The curve can be edited by double clicking on the element in the tree view, or by pressing thebutton. Then you can move the points to a new position, or click or and then click on the curve to add or remove points. You can also change the constraint type of each point.
The segment endpoints can be constrained such that adjacent control points are tangent or symmetric to the segments at the endpoint. First, start editing the curve, then pick one of the tools and then pick a point. Click again on the tool to deactivate it, so you can move the point.
- remove constraints on the points so the curve can have sharp corners.
- force adjacent control points to be tangent.
- force adjacent control points to be tangent and equidistant.
- The Points property does not yet appear in the properties list.
- OpenCascade, and thus FreeCAD, does not support Bezier curves of degrees larger than 25. This should not be a problem in practice, as most users would typically use Bezier curves of degrees 3 to 5.
- Press or the button to finish the curve, leaving it open.
- Press or the button to close the curve, that is, a segment will be added from the last point to the first one to form a face. At least four points, a curve of degree three, are required to form a face.
- Press or the button to remove the curve segments already placed, but keep editing the curve 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.
- 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 BezCurve tool will restart after you finish the curve, allowing you to draw another one without pressing the tool button again.
- Press DataMake Face ); if not, the closed wire will not make a face (DataMake Face ). or click the checkbox to toggle filled mode. If filled mode is on, a closed wire will create a filled face (
- Note: the curve should not be filled if it intersects itself, as it won't create a proper face. If the curve is filled but no shape is visible, manually set DataMake Face to to see the curve.
- 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.
- DataDegree: specifies the degree of the Bezier curve or the individual segments.
- DataClosed: specifies if the curve is closed or not. If the curve is initially open, this value is ; setting it to will draw a segment to close the curve. If the curve is initially closed, this value is ; setting it to will remove the last segment, and make the curve open.
- DataMake Face: specifies if the curve makes a face or not. If it is a face is created, otherwise only the perimeter is considered part of the object. This property only works if DataClosed is .
- Note: do not set DataMake Face to if the curve intersects itself, as it won't create a proper face.
- DataContinuity: (read-only) when the curve is closed, indicates the continuity of the curve
[0,0]. Otherwise it's
- ViewArrow Size: specifies the size of the symbol displayed at the end of the curve.
- ViewArrow Type: specifies the type of symbol displayed at the end of the curve, which can be dot, circle, arrow, and tick.
- ViewEnd Arrow: specifies whether to show a symbol at the last point of the curve, so it can be used as an annotation line.
- ViewPattern: specifies a Draft Pattern with which to fill the face of the closed curve. This property only works if DataMake Face is , and if ViewDisplay Mode is "Flat Lines".
- ViewPattern Size: specifies the size of the Draft Pattern.
BezCurve = makeBezCurve(pointslist, closed=False, placement=None, face=None, support=None, degree=None) BezCurve = makeBezCurve(Part.Wire, closed=False, placement=None, face=None, support=None, degree=None)
- Creates a
BezCurveobject with 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 curve is closed.
- If a
placementis given, it is used; otherwise the shape is created at the origin.
True, and the wire is closed, the wire will make a face, that is, it will appear filled.
import FreeCAD, Draft p1 = FreeCAD.Vector(0, 0, 0) p2 = FreeCAD.Vector(1000, 1000, 0) p3 = FreeCAD.Vector(2000, 0, 0) p4 = FreeCAD.Vector(1500, -2000, 0) BezCurve1 = Draft.makeBezCurve([p1, p2, p3, p4], closed=True) BezCurve2 = Draft.makeBezCurve([p4, 1.3*p2, p1, 4.1*p3], closed=True) BezCurve3 = Draft.makeBezCurve([1.7*p3, 1.5*p4, 2.1*p2, p1], closed=True)