AutoCAD OVERKILL

If you’ve ever opened a DWG file that felt sluggish, bloated or filled with mysterious overlapping lines, you’re not alone. Many AutoCAD users experience performance drops and plotting errors caused by duplicate geometry lurking beneath the surface. Fortunately, AutoCAD has a built-in solution designed specifically to tackle this issue: the OVERKILL command.

In this blog we’ll explore what OVERKILL does, why it’s essential for every AutoCAD professional and how to use it effectively to keep your drawings lean, clean and efficient.

What is OVERKILL?

• OVERKILL is a clean-up command in AutoCAD used to remove duplicate or overlapping geometry (lines, arcs, polylines) and optionally combine co-linear segments.
• It also help reduce file size, improve performance, avoid unintended behaviour (eg snapping to hidden overlapping objects), and clean up drawings for sharing or publishing.
• It originally started as an ‘Express Tool’ in older versions of AutoCAD and is now build into the core product (including AutoCAD LT) from 2012 onward.

How to use OVERKILL

• Open a new drawing in AutoCAD. Create 4 layers (lines and plines) as the below example:

• Draw some lines overlapping each other several times and some polylines overlapping each other, as per the below.

• With no command active, place a selection window around the lines. In the properties dialog box, you will see more lines recorded than what you can see on the screen (due to the overlapping created in the above step).

• Escape twice to select the geometry.
• Type OVERKILL in the command, re-select the line and enter.
• A dialog box opens as below.

The following prompts are displayed in the dialog box.

Object Comparison Settings

1. Tolerance: Controls the precision with this OVERKILL makes numeric comparisons. If this value is 0, the two objects being compared must match before OVERKILL modifies or deletes one of them.
2. Ignore Object Property: Select these objects properties to ignore them during comparison.
3. Options: Use these settings to control how OVERKILL deals with lines, arcs and polylines.
4. When optimise segments within polylines is selected: Individual line and arc segments within selected polylines are examined. Duplicate vertices and segments are removed. Also, OVERKILL compares individual polyline segments with completely separate line and arc segments. If a polyline segments duplicates a line or arc objects, one of them is deleted.
5. When optimise segments with polylines is not selected: Polylines are compared as discreet objects and two sub-options are selectable:
   • Ignore polyline Segment Width: ignores segment width whilst optimising polyline segments.
   • Do not break polylines: polyline objects are unchanged.
6. Combine co-linear objects that partially overlap: overlapping objects are combined into single objects.
7. Combine co-linear objects when aligned end to end: objects that have common endpoints are combined into single objects.
8. Maintain associative objects: associative objects are not deleted or modified.

• Review the result summary in the command line (CLI) to see how many duplicates or overlapping segments were deleted or combined.

• Now select the lines with a selecting window, in the properties dialog box it now displays only the remaining lines.

• Optionally, follow up with the PURGE (to remove unused named objects, layers, blocks, linetypes) and AUDIT (to check for drawing corruption) commands for a fuller clean-up.

When and why should you use it

• When you receive an imported file or someone else’s drawing with unknown history, and you suspect there are hidden overlapping/copy-over geometries.
• After major editing (copying, trimming, exploding blocks) which may leave overlapping or hidden duplicates).
• Before sending drawings to others or publishing/plotting, to reduce file size and avoid unintended plot/cut issues (especially if using CNC or file export).
• In high-density drawings (large number of objects) where performance is affected by redundant geometry.

Things to watch out for

• Always backup drawings before running massive clean-up commands.
• Check the tolerance settings. If the tolerance is too small, some ‘almost overlapping’ objects may not be picked up and if the tolerance is too big, you may inadvertently combine things you didn’t intend to.
• Be cautious if you are on different layers, have different linetypes or colours, unless you intend to ignore those properties in the comparison. The dialog box allows ignoring certain object properties.
• After running, check for unintended consequences or missing geometry (especially in drawings with complicated block references, xrefs).
• Make it part of a regular clean-up routine: OVERKILL + PURGE + AUDIT can keep your CAD workflow smooth and your drawings lean.

Think of the OVERKILL command as AutoCAD’s ‘declutter’ button. It’s fast reliable and often overlooked, yet it can dramatically improve performance, reduce file size and make your workflow smoother.

Whether you’re cleaning up imported geometry or preparing a file for handoff, running OVERKILL regularly is one of the easiest ways to keep your AutoCAD work professional and efficient.