1. Click Home tabModify panelEdit Polyline. Find
2. Select a polyline, spline, line, or arc to edit. If you selected a spline, line, or arc, press Enter to convert the selected object into a polyline.
3. Enter j (Join).
4. Select one or more polylines, splines, lines, or arcs that are located end to end.
5. Press Enter to end the command.

Converting Line to Polyline. You can convert Line to Polyline using “Polyline Edit” tool of AutoCAD, using this tool you can also convert an arc or spline into a polyline. However, you can’t convert circle, ellipse and elliptical arc into a polyline using this tool.

Note:

• Spline-fit polylines return to their original shape when joined. Polylines cannot be joined into a Y shape.
• If the properties of several objects being joined into a polyline differ, the resulting polyline inherits the properties of the first object that you selected.

Convert Line To 3d Polyline Autocad

Solution:

To convert a single spline, use the SPLINEDIT command:

1. At the command line in AutoCAD, type SPLINEDIT.
2. Select the spline if it was not already selected.
3. Type P for convert to Polyline.
4. Specify the precision <0-99>.

Before SPLINEDIT:
After SPLINEDIT:
To convert multiple splines at the same time, use the PEDIT command:

1. At the command line in AutoCAD, type PEDIT.
2. Type M for Multiple.
3. Select the splines. Note: The PEDIT command does not allow splines to be selected beforehand.
4. Type Y to Convert Lines, Arcs and Splines to polylines.
5. Specify the precision <0-99>.
6. Press the Esc key to exit the command.

As an alternative, resave the drawing in 'AutoCAD R12/LT2 DXF (*.dxf)' format using the SAVEAS command. This older file format does not support splines and will automatically change them to 3D polylines. Keep in mind though that other data structures in the drawing may also be affected.

Autocad Convert 2d Polyline To Line