Draft BSpline
Draft BSpline |
Menu location |
---|
Draft → BSpline |
Workbenches |
Draft, Arch |
Default shortcut |
B S |
Introduced in version |
0.7 |
See also |
Draft Wire, Draft BezCurve |
Description
The Draft BSpline tool creates a B-spline curve from several points. It uses the Draft Linestyle set on the Draft Tray.
The BSpline tool behaves like the Wire tool, except that each of its segments is curved instead of being a straight line. Use Wire to B-spline to convert one to the other.
The BSpline tool specifies the exact points through which the curve will go; on the other hand the Bezier curve tool uses control points to define the direction of the curve. To create exact circular or elliptical curves, use Arc and Ellipse.
Spline defined by multiple points
Usage
- Press the Draft BSpline button, or press B then S keys
- Click a first point on the 3D view, or type a coordinate and press the add point button.
- Click additional points on the 3D view, or type a coordinate and press the add point button.
- Press Esc or the Close button to complete the edition.
The spline can be edited by double clicking on the element in the tree view, or by pressing the Draft Edit button. Then you can move the points to a new position, or click add point or remove point and then click on the wire to add or remove points.
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 add 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 tool will restart after you finish the spline, allowing you to draw another one without pressing the tool 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.
Properties
A BSpline object shares most properties from a Draft Wire, however, most properties only make sense for a Wire.
Data
- DataClosed: specifies if the spline is closed or not. If the spline is initially open, this value is
false
; 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: 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 DataClosed istrue
.
- Note: do not set DataMake Face to
true
if the spline intersects itself, as it won't create a proper face.
- DataParameterization: affects the shape of the BSpline.
View
- ViewArrow Size: specifies the size of the symbol displayed at the end of the spline.
- ViewArrow Type: specifies the type of symbol displayed at the end of the spline, which can be "Dot", "Circle", "Arrow", or "Tick".
- ViewEnd Arrow: specifies whether to show a symbol at the last point of the spline, so it can be used as an annotation line.
- ViewPattern: specifies a Draft Pattern with which to fill the face of a closed spline. This property only works if DataMake Face is
true
, and if ViewDisplay Mode is "Flat Lines". - ViewPattern Size: specifies the size of the Draft Pattern.
Scripting
See also: Draft API and FreeCAD Scripting Basics.
The BSpline tool can be used in macros and from the Python console by using the following function:
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 a
placement
is given, it is used; otherwise 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
- Modification: Move, Rotate, Scale, Mirror, Offset, Trimex, Stretch, Clone, Array, Polar array, Circular array, Path array, Path link array, Point array, Point link array, Edit, Subelement highlight, Join, Split, Upgrade, Downgrade, Wire to B-spline, Draft to sketch, Set slope, Flip dimension, Shape 2D view
- Draft Tray: Select plane, Set style, Toggle construction mode, AutoGroup
- Snapping: Snap lock, Snap endpoint, Snap midpoint, Snap center, Snap angle, Snap intersection, Snap perpendicular, Snap extension, Snap parallel, Snap special, Snap near, Snap ortho, Snap grid, Snap working plane, Snap dimensions, Toggle grid
- 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
- Getting started
- Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
- Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate
- Help: Tutorials, Video tutorials
- Workbenches: Std Base, Assembly, BIM, CAM, Draft, FEM, Inspection, Material, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Surface, TechDraw, Test Framework
- Hubs: User hub, Power users hub, Developer hub