Editing a Spline
Ribbon: Home, Draw – Modify > Edit Splines

Menu: Modify – Object > Spline

Toolbar: Modify Object

Command line: SPE, SPLINEDIT

Double clicking on a spline starts the editing mode.

This command allows changing of a spline’s shape by adding, deleting or replacing characteristic points, changing the direction of tangents at the start and end points of the spline. Using this command, you can close or open a spline, change a tolerance value. A tolerance defines the maximum distance from the real spline to any of its characteristic points. The smaller the value a tolerance has, the closer the spline is to the characteristic points.

Command options:

? Opens the additional options to select objects.

Fit data Switches to the editing of spline data mode, including tolerance values.

The option starts the following prompt in the command line:

Enter an option [+Add/Close/Delete/Move/Purge/Tangents/ Tolerance/Exit/] :


Add – Adds characteristic points to the spline

Close/Open – Closes/Opens spline with fitting at a join point.

Delete – Deletes characteristic points from the spline and rebuilds the spline

Move – Changes the position of the previous point.

Purge – Deletes the spline data from the document database.

Tangents – Edits the start and end points of the spline.

tolerance – Specifies a new tolerance value.

eXit – Returns to the main prompt in the command line.

The Tangents option starts the following option in the command line:

Specify start tangent or [System default]:


System default – Sets tangents at the spline ends by default

Close Closes an open spline with fitting at a join point.

Open Opens a closed spline.

Move vertex Changes the position of control vertexes and deletion of characteristic points.

Refine Changes the spline’s shape.The Refine options starts the following prompt in the command line: Enter a refine option [Add control point/Elevate order/Weight/Exit] :


Add control point – Adds a control point near the point, selected on spline, between two control points.
Elevate order -Increases the degree of the spline (increases the number of control points).
Weight – Changes the weight factors at the control points of the spline (the greater the weight factor is, the closer the spline is to the control point).
eXit – Returns to the main prompt in the command line.

rEverse Changes the spline direction to the opposite (start and end points changes their places).

Exit Closes the spline editing mode.

The Move vertex and Weight of the SPLINEDIT starts the following prompts in the command line:

Specify new location or [Next/Previous/Select point/Exit/] : and Specify new weight (current = 1.0000) or [Next/Previous/Select point/Exit]:


Next Selects the next point.

Previous Selects the previous point.

Select point Selects the control point.

eXit Returns to the previous prompt in the command line.

Command prompts:

Select spline or [?]: Select a spline.

Enter an option Fit data/Close/Move vertex/ Refine/rEverse/Undo/eXit: Select the required option. To finish editing, select Exit option.

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