Is a Polyline considered a single object or a group of segments in AutoCAD?
Is a Polyline considered a single object or a group of segments in AutoCAD?
Short Answer
Yes. In AutoCAD, a polyline is generally considered a single object, even though it can contain multiple line and arc segments within it. The most common professional way to create or edit it is with PLINE. However, exploded polylines stop behaving as one object.
What You Need to Know Before
Warning: A polyline may look like separate connected segments, but AutoCAD treats it as one object for selection, properties, length, and width. A common failure happens after using EXPLODE, because the object then loses unified editing behavior and becomes separate entities.
How to Check or Work With a Polyline
Command: LIST
Shortcut: LI
Quick Steps:
- On the Ribbon, go to Home tab > Utilities panel, then run LIST.
- Select the object you want to verify and press Enter.
- Read the command line result; if AutoCAD reports Polyline, it is a single object, even if it contains multiple segments.
A useful option is checking the Properties palette with Ctrl+1 to confirm whether the object is listed as Polyline and whether Closed = Yes/No.
Variables & Settings
Key Setting: Closed property in the Properties palette
Expert Setting: This property controls whether the polyline is treated as an open path or a closed boundary. A closed polyline is still one object, but it behaves differently for hatching, area calculation, and boundary-based commands.
Why it Fails
- Cause 1 (Geometry): The object was exploded, so the original polyline became separate lines and arcs.
- Cause 2 (layers/Locks): Part of the geometry may be on a locked layer, preventing proper editing or joining into one polyline.
- Cause 3 (Command/Logic): Users often confuse visually connected lines with a true polyline; connected segments are not a single object unless they were created as one polyline or joined correctly.
Quick Fix & Best Practice
- Quick Fix: Use PEDIT and choose Join to convert connected lines/arcs into one polyline.
- Manager’s Verdict: Use polylines whenever possible for outlines, paths, and boundaries because they are easier to edit, measure, hatch, and manage than separate segments.
FAQ
Can a polyline contain arc segments in AutoCAD?
Yes, a single polyline can include both line and arc segments.
Does selecting one polyline select all its segments?
Yes, because AutoCAD treats the polyline as one object.
Can separate lines be turned into one polyline?
Yes, use PEDIT with the Join option.
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