How to Straighten a Curved Line in Autocad

To straighten a curved line in AutoCAD, the primary tool you will use is the PEDIT command, especially when dealing with objects that are or can become polylines.

Straightening Curves and Polylines

Straightening a curved line or converting a curved polyline into a straight one in AutoCAD often involves using the PEDIT (Polyline Edit) command. This command is versatile for modifying polylines and can also be used to convert certain other objects, like arcs or splines, into polylines for editing.

According to sources, including a reference from 25-Nov-2021, you can use the pedit command to turn curves or polylines into straight lines. While PEDIT itself doesn't have a direct "straighten" button for a complex curve, it allows you to edit the vertices of a polyline. By reducing the number of vertices to just the start and end points, or by simplifying the polyline, you can effectively turn a curved segment into a straight line connecting its endpoints.

Steps Using the PEDIT Command

Here’s a general workflow for using the PEDIT command to straighten a curved line, assuming it's a polyline or convertible to one:

1. Start the Command: Type PEDIT on the command line and press Enter.
2. Select the Object: You will be prompted to select the polyline or object you want to edit. Click on the curved line.
3. Convert to Polyline (if necessary): If the selected object is not already a polyline (e.g., it's an Arc or Spline), AutoCAD will likely ask if you want to turn it into one. Type Y for Yes and press Enter.
4. Choose an Editing Option: Once the object is a polyline, you'll see various PEDIT options. To make it straight, you generally need to simplify the polyline geometry. A common way to achieve a straight line between the original endpoints is to edit the vertices.
   • Type E for Edit Vertex and press Enter.
   • Use the Next (N) and Previous (P) options to navigate the vertices.
   • Use the Delete (D) option to remove intermediate vertices that create the curve. Carefully delete vertices until only the start and end vertices remain.
   • Press X to exit the Edit Vertex mode once done.
   • Press Enter to exit the PEDIT command.

Alternatively, for complex polylines or splines converted to polylines, simply deleting intermediate vertices might be the most straightforward way to force the line straight between two points.

The result will typically be a straight polyline segment connecting the approximate start and end points of the original curve, depending on how you simplified it.