SPLINE

Creates a smooth curve that passes through or near specified points.

Access Methods

Button

Ribbon: Home tabDraw panelSplineNot available on the ribbon in the current workspace
Toolbar: Draw
Command entry: spline

Specify first point or [ Object]: Specify a point or enter o

You can control the maximum distance between the B-spline curve and the fit points, shown in the illustration, by changing the value for the fit tolerance with SPLINEDIT. You can also display the control frames for B-splines with SPLFRAME.

First Point

Creates a spline using points you specify, using NURBS (nonuniform rational B-splines) mathematics.

Specify next point: Specify a point

Enter points until you have defined the spline curve. After you enter two points, the following prompt is displayed:

Specify next point or [Close/Fit Tolerance] <Start tangent>: Specify a point, enter an option, or press Enter

Next Point

Continuing to enter points adds additional spline curve segments until you press Enter. Enter undo to remove the last point specified. Once you press Enter, you are prompted to specify the start tangent for the spline curve.

Close

Closes the spline curve by defining the last point as co-incident with the first and making it tangent to the joint.

Specify tangent: Specify a point or press Enter

Specify a point to define the tangent vector or use the Tangent and Perpendicular object snap modes to make the spline tangent or perpendicular to existing objects.

Fit Tolerance

Changes the tolerance for fitting of the current spline curve. The spline curve is redefined so that it fits through the existing points according to the new tolerance. You can repeatedly change the fit tolerance, but doing so changes the fit tolerance for all the control points regardless of the control point that is selected.

Specify fit tolerance <current>: Enter a value or press Enter

If you set the tolerance to 0, the spline curve passes through the fit points. Entering a tolerance greater than 0 allows the spline curve to pass through the fit points within the specified tolerance.

SPLINE returns to the previous prompt.

Start Tangent

Defines the tangency for the first and last points of the spline curve.

Specify start tangent: Specify a point or press Enter

The Specify Start Tangent prompt specifies the tangency of the spline curve at the first point.

Specify end tangent:Specify a point or press Enter

The Specify End Tangent prompt specifies the tangency of the spline curve at the last point.

If you specify tangency at both endpoints of the spline, you can enter a point or use the Tangent and Perpendicular object snap modes to make the spline tangent or perpendicular to existing objects. Press Enter to calculate default tangents.

Object

Converts 2D or 3D quadratic or cubic spline-fit polylines to equivalent splines and (depending on the setting of the DELOBJ system variable) deletes the polylines.

Select objects to convert to splines...

Select objects: Select 2D or 3D spline-fit polylines and press Enter when you finish