Convert line to polyline and spline in AutoCAD

At times you may need to convert line to polyline or polyline to a spline and sometimes Spline to a Polyline.

You can do all of these tasks using a few simple commands, let’s see the step-by-step method of converting these curves.

Convert Line to Polyline

You can convert a Line to a Polyline using the “Polyline Edit” tool of AutoCAD.

Using this tool you can also convert an arc or a spline into a polyline.

However, you can’t convert a circle, ellipse and elliptical arc into a polyline using this tool.

To start this, type PE on the command line and press Enter to start the “Polyline Edit” command.

The command line will prompt you to select objects for making changes.

Click on the object which you want to change to polyline, you can also select multiple objects by selecting Multiple from the command prompt.

Once you have made the selection a new prompt will appear on the command line stating that the “selected object is not a polyline do you want to convert it” as shown in the image below.

Type Y and press enter twice to convert the object into a polyline and exit this command.

Convert Polyline into Spline

To convert a polyline into spline type PE and press enter, then select the polyline which you want to convert and select spline from the prompt appearing on the command line.

Press enter to exit the polyline edit command.

This will convert your polyline into a “polyline spline” which looks like a spline but inherits properties of the 2D polyline.

To convert it into true spline type SPE on the command line and press Enter.

This will start the Spline Edit command, select “polyline spline” from the drawing area and press Enter.

The 2D polyline we created in the previous step will be converted into a true spline and it will also inherit all the properties of a spline.

Convert Spline into Polyline

To convert a Spline into a polyline type PE on the command line press enter then select the spline from the drawing area and press enter again.

The spline will be converted into a polyline.

Alternatively, you can also use Spline Edit (SPE) command to convert a “true spline” into a polyline by simply selecting the “Convert to Polyline” option from the command line options.

In this case when the command prompts you to specify the precision enter the default value 10 or any other value which you like.

The higher the value of precision more accurate will be the converted polyline with respect to the spline but it will also create a dense polyline.

The value of precision can be set between 0 and 99.

Thanks, R.K. McSwain for suggesting this tip, see more tips from him on  Cadpanacea. If you have questions related to this tip let me know in the comments below.