What is a "spline" ?

[thornuk]

I'm not sure how QCad is using the term "spline".
I'm used to it referring to (eg:) a grooved circumference of a shaft onto which a similarly grooved hole in a cog or gear wheel (to lock the two together for drive purposes.
Thanks
PeterB

QCad version: 3.28.1.0 (3.28.1)
Windows 10

[andrew]

In QCAD / CAD / mathematics, a spline is a type of curve:
https://en.wikipedia.org/wiki/Spline_(mathematics)

[thornuk]

Thanks, Andrew,
Would that be an equivalent to a Bezier Curve ?

[CVH]

Would that be an equivalent to a Bezier Curve ?

About, not really, I think that the supported types are B-Splines aka Non-uniform rational Basis-spline (NURBS).
In the wiki link by Andrew see 'Representations and names'
Also see: https://www.qcad.org/rsforum/viewtopic. ... 8665#p8665
On the Bézier curve there is another wiki: https://en.wikipedia.org/wiki/B%C3%A9zier_curve
And on NURBS: https://en.wikipedia.org/wiki/Non-unifo ... l_B-spline

A cubic Bézier curve has for example 4 control points, a cubic control point spline has at least 4 control points in QCAD.

One can convert the splines to Bézier segments, see: Misc .. Modify .. Convert Splines to Bézier Segments.
Not native but besides control and fitpoint splines QCAD support something that looks like a chain of Bézier Segments.

Regards,
CVH

[thornuk]

Many thanks CVM.