LinceCAD SPLINE — Spline
Creates a smooth curve through the specified points.
- Command:
SPLINE· Global name:_SPLINE· Alias:SPL - Ribbon: Home › Draw
- Menu: Draw
- Toolbar: Draw
Draws a smooth curve (spline). By default the curve passes through the points you specify (Fit method); with the CV method, the points are control vertices that pull the curve.
Usage
- Enter SPLINE (or SPL) or click Spline.
- Specify the first point, or first change the method, the knots or the degree.
Specify first point or [Method/Knots/Object]:
- Specify the next points.
Enter next point or [start Tangency/toLerance]: Enter next point or [end Tangency/toLerance/Undo/Close]:
- Press Enter to finish.
Options
- Method (M): chooses the method.
Enter spline creation method [Fit/CV] <Fit>:
- Knots (K): in the Fit method, how the knots are spaced between the points: by the distance between them (Chord), by its square root (S) or evenly (Uniform).
Enter knot parameterization [Chord/Square root/Uniform] <Chord>:
- Degree (D): in the CV method, the degree of the curve, from 1 to 10 (3 by default).
Enter degree of spline <3>:
- start Tangency (T): after the first point, the direction in which the curve leaves.
- end Tangency (T): the direction in which it reaches the last point; ends the spline. Enter at a tangent prompt leaves it free.
- Close (C): with three points or more, closes the curve and ends the command. By CVs, with any degree, the closed spline is periodic (smooth at the joint), as in AutoCAD.
- toLerance (L): with a value greater than 0, the curve no longer passes through the points but within that distance of them, smoother; the points entered and the tolerance are stored.
Specify fit tolerance <…>:
- Object (O): select spline-fit polylines (AutoCAD PEDIT Spline) and press Enter: each one becomes the equivalent quadratic or cubic spline, with its frame as control vertices, and the polyline is erased.
Select spline-fit polyline:
- Undo (U): removes the last point.
Notes
- A fit spline stores its fit points and tangents as AutoCAD does, which recognizes and edits it in the same way.
- With toLerance, the curve is smoothed differently from AutoCAD; when it opens the DWG, AutoCAD recalculates it from the stored points and tolerance.
- To edit the curve later, use SPLINEDIT.