Draft BSpline

Description
The BSpline tool creates a B-Spline curve from several points in the current work plane. It takes the linewidth and color previously set on the Tasks tab. The BSpline tool behaves exactly like the Draft Wire tool.



How to use

 * 1) Press the  button, or press  then  keys
 * 2) Click a first point on the 3D view, or type a coordinate
 * 3) Click additional point on the 3D view, or type a coordinate
 * 4) Press  or, or double-click the last point, or click on the first point to finish or close the spline. If the spline is closed, it will also be a face, even if it appears as wireframe.

Options

 * Press or the  button to finish the spline, leaving it open
 * Press or the  button or click on the first point to finish the spline, but making it closed by adding a last segment between the last point and the first one.
 * 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 check/uncheck the  button. 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 (0,0,0) origin point.
 * Press or click the checkbox to check/uncheck the  button. If continue mode is on, the BSpline tool will restart after you finish or close it, allowing you to draw another one without pressing the BSpline button again.
 * Press while drawing to force snapping your point to the nearest snap location, independently of the distance.
 * Press while drawing to constrain your next point horizontally or vertically in relation to the last one.
 * Press or press the  button to remove the existing segments and start the spline from the last point.
 * Press + or press the button to undo the last point.
 * Press or the  button to have the spline to appear as a face after it has been closed. This simply sets the View->Property of the Wire to "Flat lines" or "Wireframe", so it can easily be changed later.
 * Press or the  button to abort the current BSpline command.

Properties

 * : Specifies if the spline is closed or not
 * : Shows an arrow symbol at the last point of the spline, so it can be used as an annotation leader line

Scripting
The BSpline tool can by used in macros and from the python console by using the following function:

makeBSpline (pointslist,[closed],[placement]) : Creates a B-Spline object from the given list of vectors. If closed is True or first and last points are identical, the wire is closed. If face is true (and the bspline is closed), the bspline will appear filled. Instead of a list of points, you can also pass a Part Wire. Returns the newly created object.

Example:

import FreeCAD,Draft p1 = FreeCAD.Vector(0,0,0) p2 = FreeCAD.Vector(1,1,0) p3 = FreeCAD.Vector(2,0,0) Draft.makeBSpline([p1,p2,p3],closed=True)