Polyline editing (PEDIT) in AutoCAD - Step-by-Step Guide

Introduction

Polyline editing lets you change the shape and properties of connected lines and curves in your drawing. It helps fix or improve shapes without redrawing them from scratch.

When you want to join several line segments into one continuous shape.

When you need to convert a simple line into a polyline for easier editing.

When you want to smooth sharp corners by converting segments to curves.

When you need to close an open shape to make it a complete loop.

When you want to change the width of a polyline segment.

Steps

Step 1: Type PEDIT and press Enter

- Command line

AutoCAD prompts you to select a polyline or line

💡 You can also find PEDIT in the Modify panel under the Home tab

Step 2: Select the polyline or line you want to edit

- Drawing area

AutoCAD recognizes the object and shows PEDIT options

Step 3: If you selected a line, type Y and press Enter to convert it to a polyline

- Command line prompt

The line becomes a polyline ready for editing

Step 4: Choose an option like Join, Width, Close, or Edit vertex

- Command line options

The polyline updates based on your choice, for example joining segments or closing the shape

Step 5: Follow prompts to select additional objects or enter values

- Command line

The polyline changes as specified, such as joining lines or changing width

Step 6: Press Enter to finish editing

- Command line

The polyline editing session ends and changes are saved

Before vs After

Before

Several separate line segments forming a rough rectangle with gaps

After

One continuous closed polyline forming a smooth rectangle shape

Settings Reference

Join

📍 PEDIT command options

Combine multiple connected lines or polylines into one polyline

Default: No objects joined

Width

📍 PEDIT command options

Set the thickness of the polyline segments

Default: 0 (no width)

Close

📍 PEDIT command options

Close an open polyline by connecting the last point to the first

Default: No

Edit vertex

📍 PEDIT command options

Modify individual points of the polyline

Default: No vertex editing

Common Mistakes

Selecting a line and not converting it to a polyline before editing

PEDIT only works on polylines, so lines must be converted first

When prompted after selecting a line, type Y to convert it to a polyline

Trying to join lines that are not touching or overlapping

PEDIT Join only works on connected segments

Ensure lines share endpoints or overlap before joining

Forgetting to close an open polyline when a closed shape is needed

Open polylines do not form enclosed areas for some operations

Use the Close option in PEDIT to connect the last point to the first

Summary

Polyline editing lets you join, shape, and modify connected lines easily.

You must convert lines to polylines before editing with PEDIT.

Use options like Join and Close to create smooth, continuous shapes.

Practice

1. What is the primary purpose of the PEDIT command in AutoCAD?

easy

A. To edit polylines by joining, smoothing, or changing their shape

B. To create new layers for organizing drawings

C. To measure distances between points

D. To change the color of objects

Solution

1. Step 1: Understand the function of PEDIT

   The PEDIT command is designed specifically for editing polylines, allowing users to join segments, smooth curves, and modify shapes.

2. Step 2: Compare with other options

   Options A, B, and C relate to coloring, layers, and measuring, which are not the main functions of PEDIT.

3. Final Answer:

   To edit polylines by joining, smoothing, or changing their shape -> Option A

4. Quick Check:

   PEDIT edits polylines = D [OK]

Hint: PEDIT is for polylines editing only, not layers or colors [OK]

Common Mistakes:

• Confusing PEDIT with layer management commands
• Thinking PEDIT measures distances
• Assuming PEDIT changes object colors

2. Which of the following is the correct syntax to start the PEDIT command in AutoCAD?

easy

A. EDITPOLYLINE

B. POLYEDIT

C. PLINEEDIT

D. PEDIT

Solution

1. Step 1: Recall the exact command name

   The correct command to edit polylines in AutoCAD is PEDIT.

2. Step 2: Verify other options

   Options A, B, and D are incorrect as they are not recognized AutoCAD commands for polyline editing.

3. Final Answer:

   PEDIT -> Option D

4. Quick Check:

   Command to edit polylines = PEDIT [OK]

Hint: Remember the exact command: PEDIT, not variations [OK]

Common Mistakes:

• Typing similar but incorrect commands like POLYEDIT
• Using full words instead of command abbreviations
• Confusing with other editing commands

3. Given a polyline with two separate segments, what will happen if you use PEDIT and choose the Join option with a small gap between segments?

medium

A. The segments will remain separate regardless of gap size

B. The segments will join into a single polyline if the gap is within the specified tolerance

C. The segments will be deleted

D. The command will produce an error and stop

Solution

1. Step 1: Understand the Join option in PEDIT

   The Join option in PEDIT connects separate polyline segments into one if the gap between them is less than the specified joining tolerance.

2. Step 2: Analyze the effect of gap size

   If the gap is small enough, the segments join; if too large, they stay separate. No deletion or errors occur.

3. Final Answer:

   The segments will join into a single polyline if the gap is within the specified tolerance -> Option B

4. Quick Check:

   Join merges close segments = A [OK]

Hint: Join works only if gap is small enough [OK]

Common Mistakes:

• Assuming segments join regardless of gap size
• Thinking segments get deleted after join
• Expecting errors when joining segments

4. You tried to use PEDIT to join two polylines but got an error saying "Object is not a polyline." What is the most likely cause?

medium

A. One or both objects are simple lines, not polylines

B. The polylines are on different layers

C. The drawing is corrupted

D. You did not select any object

Solution

1. Step 1: Understand the error message

   The error "Object is not a polyline" means the selected object is not recognized as a polyline by AutoCAD.

2. Step 2: Identify common causes

   Simple lines are different from polylines and cannot be edited with PEDIT unless converted first.

3. Final Answer:

   One or both objects are simple lines, not polylines -> Option A

4. Quick Check:

   Non-polyline objects cause this error = B [OK]

Hint: Check if objects are polylines before using PEDIT [OK]

Common Mistakes:

• Assuming layer differences cause this error
• Blaming drawing corruption without checking object type
• Ignoring selection step

5. You have a polyline with sharp corners, and you want to smooth it by converting corners into curves. Which PEDIT option should you use, and what additional parameter must you specify?

hard

A. Use the Join option and specify the curve smoothness

B. Use the Width option and set a curve radius

C. Use the Spline option and specify the fit tolerance

D. Use the Spline option to smooth the polyline; no additional parameter needed

Solution

1. Step 1: Identify the smoothing option in PEDIT

   The Spline option converts sharp corners into smooth curves on a polyline.

2. Step 2: Understand the parameter needed

   When using Spline, you must specify the fit tolerance to control how smooth the curve becomes.

3. Final Answer:

   Use the Spline option and specify the fit tolerance -> Option C

4. Quick Check:

   Spline with fit tolerance smooths corners = A [OK]

Hint: Spline option needs fit tolerance for smooth curves [OK]

Common Mistakes:

• Using Join instead of Spline for smoothing
• Setting Width instead of fit tolerance
• Skipping the fit tolerance parameter