Fix Common Geometry Issues with MAPCLEAN

AutoCAD Map 3D has a great unsung hero command named MAPCLEAN. Autodesk Civil 3D includes it too. Core AutoCAD still does not, which is unfortunate because this one tool fixes the kind of geometry problems everyone runs into.

MAPCLEAN cleans up the messy linework that comes from survey files, GIS imports, scanned drawings, and years of back and forth between teams. Overshoots. Undershoots. Duplicates. Bad intersections. Zero length junk. Stray nodes. These issues slow down design work and cause problems in Civil 3D such as performance or stability issues.

MAPCLEAN gives you a simple workflow.

You start the command.
You pick the objects you want to clean. You can select by layer or by object class if that is easier.
You can choose anchor objects that stay fixed during cleanup.

Image of AutoCAD Map 3D 'Select Objects' dialog box for the MAPCLEAN command, featuring options to select layers and object classes for cleanup.

You then choose the cleanup actions. Each action fixes one problem. Delete duplicates. Erase short fragments. Break crossing lines. Extend undershoots. Remove overshoots. Snap node clusters. Dissolve pseudo nodes. Simplify two dimensional linework. Remove zero length objects. Weed polylines. You can tune tolerances for each action and you can reorder them to get the outcome you want. The tool runs the first action before moving to the next one.

You can run in interactive mode and review the fixes with markers or you can run in automatic mode and clean everything at once.

AutoCAD MAPCLEAN command interface displaying available cleanup actions such as 'Delete Duplicates,' 'Erase Short Objects,' and 'Extend Undershoots.'
Screenshot of the Drawing Cleanup dialog in AutoCAD Map 3D, showing options for treating cleaned objects and converting selected objects.

You choose how it treats the original geometry. You can modify it. Keep it. Replace it.
Or convert everything like Line to Polylines.

A table illustrating the cleanup actions for drawing geometry in AutoCAD, showing examples of problems before cleanup such as duplicate objects, short objects, crossing objects, undershoots, node clusters, pseudo-nodes, dangling objects, and zero-length objects, alongside their respective cleanup actions like deleting duplicates and simplifying objects.

You can even save your settings as a Dreawing Cleanup Profile so you can repeat the same settings to cleanup drawings.

Screenshot of the Drawing Cleanup interface in AutoCAD, displaying options to select a cleanup profile and corresponding folders.

MAPCLEAN should be part of every project intake because clean geometry prevents many downstream issues. Better surfaces. Cleaner offsets. Fewer topology errors. Fewer corridor surprises. Faster files.

There are other cleanup tools in AutoCAD that help round out this workflow. Purge removes unused layers, blocks, and styles. Overkill removes overlapping or duplicate objects. Both are useful and many people run them before or after MAPCLEAN.

It is surprising that MAPCLEAN never made it into plain core AutoCAD, yet. The need for clean geometry is not limited to civil work. Anyone who opens DWG files from external sources would benefit from it.

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