Quick Reference
See Also

Edits a spline or spline-fit polyline.

Access Methods


 Ribbon: Home tabModify panelEdit SplineNot available on the ribbon in the current workspace
 Menu: ModifyObjectsSplineNot available in menus in the current workspace
 Toolbar: Modify II 
 Shortcut menu: Right-click a selected spline, and click Spline Edit.


Modifies a spline’s definition, such as the number and weight of control vertices, the fit tolerance, and the start and end tangents.

When you select a spline object or spline-fit polyline, grips appear at the control vertices.

Fit data consists of all fit points, the fit tolerance, and tangents associated with splines created with the SPLINE command.

A spline can lose its fit data if you

  • Use the Purge option while editing fit data
  • Refine the spline by elevating the order, adding or deleting a control vertex, or changing the weight of a control vertex
  • Change the fit tolerance
  • Move a control vertex
  • Trim, break, stretch, or lengthen the spline
NoteSPLINEDIT automatically converts spline-fit polylines to splines even if you immediately exit SPLINEDIT after selecting the spline-fit polyline.

List of Prompts

The following prompts are displayed.

Select spline:

Enter an option [Close/Join/Fit data/Edit Vertex/convert to Polyline/Reverse/Undo] <eXit>:


Switches between Close and Open, depending on whether the selected spline is closed.


Closes an open spline and makes it tangentially continuous (smooth) at its endpoints. If the spline's start point and endpoint are the same, this option makes the spline tangentially continuous at both points.


Opens a closed spline. If the spline's start point and endpoint were the same before using the Close option, the spline is returned to its original state. The start point and endpoint remain the same but, lose their tangential continuity (smoothness).

If the spline was open (its start point and endpoint were not the same) before using the Close option the spline is returned to its original open state and tangential continuity is removed.


Selected splines, lines, and arcs are joined to existing splines at coincident endpoints. After a valid object is selected, it is joined to the current spline with a kink at the join point.

Fit Data

Edits fit data using the following options:

Enter a fit data option: [Add/Delete/Kink/Move/Purge/Tangents/toLerance/eXit] <eXit>:


Adds fit points to a spline.

When you select a point, SPLINEDIT highlights it and the next point and interprets the new point to go between the highlighted points. Selecting the last point on an open spline highlights only that point, and SPLINEDIT adds the new point after the last. If you select the first point on an open spline, you have the option of placing the new point before or after the first point.

The point is added, and the spline is refitted through the new set of points.


Closes the spline


Removes fit points from a spline and refits the spline through the remaining points.


Adds a knot and fit point at the selected point on the spline.


Moves fit points to a new location.

New Location

Moves the selected point to the specified location.


Moves selection to the next point.


Moves selection to the previous point.

Select Point

Selects a point from the set of fit points.


Removes a spline's fit data from the drawing database. After purging the spline's fit data, the main SPLINEDIT prompt is displayed without the Fit Data option.


Edits the start and end tangents of a spline.

If the spline is closed, the prompt becomes

Specify Tangent or [System Default].

The System Default option calculates the default end tangents.

You can specify a point or use the Tangent or Perpendicular object snap mode to make the spline tangential or perpendicular to existing objects.


Refits the spline to the existing points with new tolerance values.


Returns to the main SPLINEDIT prompt.

Edit Vertex

Fine-tunes a spline definition. The following prompts display:

Enter a vertex editing option [Add/Delete/Elevate order/Move/Weight/eXit] <eXit>:


Increases the number of control vertices that control a portion of a spline.

SPLINEDIT adds a new control vertex close to the point you select, between the two control vertices affecting that portion of the spline.


Decreases the number of control vertices that define the spline.

Elevate Order

Increases the number of control vertices on the spline.

Entering a value greater than the current value increases the number of control points uniformly across the spline for more localized control. The maximum value is 26.


Relocates a spline's control vertices and purges the fit points.


Changes the weight at various control vertices. A larger weight value pulls the spline closer to the control vertex.

New Weight

Recalculates the spline based on the new weight value at the selected control point. The larger the integer value, the more the spline is pulled toward the control point.


Returns to the main SPLINEDIT prompt.

Convert to Polyline

Converts the spline to a polyline.

The precision value determines how accurately the resulting polyline is to fit to the source spline. Valid values are any integer between 0 and 99.

NoteA high precision value may cause performance problems.

The PLINECONVERTMODE system variable determines whether the polylines are created with linear or arc segments.

The conversion in both PEDIT and SPLINEDIT will obey the DELOBJ system variable.


Reverses the spline's direction. This option is intended primarily for third-party applications.


Cancels the last editing action.