Can I Convert a 3D Polyline to 2D AutoCAD?

Can I Convert a 3D Polyline to 2D AutoCAD?

If you are working with AutoCAD and dealing with 3D polylines, you may come across situations where you need to convert them into 2D polylines. Fortunately, AutoCAD provides a simple and straightforward method to achieve this. In this tutorial, we will explore how to convert a 3D polyline to a 2D polyline using AutoCAD.

Understanding Polylines in AutoCAD

Before diving into the conversion process, let’s quickly recap what polylines are in the context of AutoCAD. A polyline is a single object that consists of one or more connected line segments or arcs. It is commonly used for drawing complex shapes and paths.

By default, when you create a polyline in AutoCAD, it is created as a 2D object. This means that all the vertices lie in the same plane. However, there might be instances where you end up with a 3D polyline unintentionally or purposely and later realize that it needs to be converted to 2D for various reasons.

The Conversion Process

To convert a 3D polyline to a 2D polyline in AutoCAD, follow these steps:

  1. Select the 3D polyline that you want to convert by clicking on it.
  2. Go to the Modify menu or type “PEdit” in the command line and press Enter.
  3. The “Polyline Edit” dialog box will appear. Here, select the “Convert Lines/Arcs/Polygons” option.
  4. Next, choose “Convert To Polyline” from the list of options.
  5. In the next prompt, specify whether you want to keep or delete the source object. Choose the desired option based on your requirements.
  6. Press Enter to complete the conversion process.

Once you have completed these steps, you will have successfully converted your 3D polyline into a 2D polyline.

Benefits of Converting to a 2D Polyline

Now that you know how to convert a 3D polyline to a 2D polyline, let’s explore why you might want to perform this conversion:

  • Simplification: Converting a 3D polyline to 2D can help simplify your drawing and make it easier to work with. It removes any unnecessary complexity that might not be required for your specific project.
  • Compatibility: Some software or applications may only support 2D polylines. By converting your drawing to 2D, you ensure compatibility with these tools.
  • Faster Rendering: Working with 2D polylines can improve the performance and rendering speed of your AutoCAD drawings, especially when dealing with large and complex designs.

Tips for Working with Polylines in AutoCAD

To make the most out of AutoCAD’s polyline functionality, consider the following tips:

  • Edit Vertices: You can easily modify the shape of a polyline by editing its vertices. Use commands like “Pedit,” “Move,” or “Stretch” to manipulate individual vertices or segments.
  • Closed Polylines: If you need a closed shape, ensure that the first and last vertices of your polyline are connected.

    You can use the “Close” command or adjust them manually.

  • Polyline Thickness: Adjusting the thickness of a polyline can help differentiate it from other objects in your drawing. Use the “Plinegen” command to control the display thickness.


In conclusion, converting a 3D polyline to a 2D polyline in AutoCAD is a simple yet powerful feature that can significantly enhance your drawing workflow. By following the step-by-step process outlined in this tutorial, you can easily convert your polylines and enjoy the benefits of working with 2D objects.

Remember to utilize the various tools AutoCAD offers when working with polylines, such as editing vertices and adjusting thickness, to create precise and visually appealing drawings.