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CAD drafting Spline 0   Menu: Draw – CAD software Spline 1 Spline

CAD drawing Spline 2   Toolbar: Draw – CAD drafting Spline 3

CAD software Spline 4 Command line: SPL, SPLINE

A spline is a smooth curve passing through a given set of points. Example of spline usage: line breaks of objects.

Spline can be created by two methods:

Fit points

CAD drawing Spline 5

When creating splines using fit points, the resulting curve goes through the specified points and depends on intervals between mathematic knots of curve.

Control vertices

CAD drafting Spline 6

When creating splines using control vertices, temporary lines are displayed between the specified points, they form control polygon that defines the spline form.


Command options:


Selects the method of creation [Fit/Control]


Converts a polyline, smoothed by the Spline and Smooth commands, to an equivalent spline.


Closes a spline.

Fit tolerance

The maximum distance from a spline curve to any points defining it.


Successively reverses the specified points. It is impossible to undo the specified start point.


Creating Splines by Fit Points Method

CAD software Spline 7    Ribbon: Main – Draw > CAD drawing Spline 8 Fit points

CAD drafting Spline 9    Menu: Draw – Spline > CAD software Spline 10 Fit points

CAD drawing Spline 11    Toolbar: Draw – CAD drafting Spline 12 Fit points

CAD software Spline 13 Command line: SPL, SPLINE – Method > Fit

CAD drawing Spline 14


Command prompts:

Current settings:



Specify first point or [Method/Object]:

Specify a start point 1.

Specify second point:

Specify second point 2.

Specify next point [Fit tolerance/Undo] <start tangent>

Specify 3, 4, 5 etc. points.

Specify next point or [Close/Fit tolerance/Undo] <start tangent>

Press ENTER to finish specifying points.

Specify start tangent:

Specify a tangent 6 for the start spline point.

Specify end tangent:

Specify a tangent 7 for the end spline point.

Creating Splines by Control Vertices Method

CAD drafting Spline 15    Ribbon: Main – Draw > CAD software Spline 16 Control vertices

CAD drawing Spline 17    Manu: Draw – Spline > CAD drafting Spline 18 Control vertices

CAD software Spline 19    Toolbar: Draw – CAD drawing Spline 20 Control vertices

CAD drafting Spline 21 Command line: SPL, SPLINE – Method > Control

Command prompts:

Current settings: Method=Cv


Specify first point or [Method/Object]:

Specify the spline start point.

Specify second point:

Specify the second point.

Specify next point or [Undo]:

Specify the next point.

Specify next point or [Close/Undo]:

Specify all next points. Press ENTER to close the command.

Converting Objects to Spline

Lines, polylines, spline-smoothed polylines, arcs, circles, elliptical arcs can be transformed into a spline.

Specify first point or [Method/Object]: Object

Select the Object option.

Select objects to convert to splines or [?]:

Select objects.


Press ENTER to complete the command.

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