AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

Active Contributor
Posts: 45
Registered: ‎01-18-2008
Message 1 of 3 (1,315 Views)

Illegal (self-intersecting or non-closed) Boundary Polyline

1315 Views, 2 Replies
05-01-2012 08:52 AM

I always get the message after I make a closed boundary polygon, and I know it's a closed boundary, but I know how to fix it.  It just bugs me sometimes when the message pops up when I add it as a boundary under the definition of a surface.

*Expert Elite*
Posts: 2,871
Registered: ‎11-13-2006
Message 2 of 3 (1,309 Views)

Re: Illegal (self-intersecting or non-closed) Boundary Polyline

05-01-2012 09:00 AM in reply to: mramseur

Somewhere in the pline there is funky geometry. This could be crossing objects, null or psuedo nodes, zero length objects, incorrect closure when creating the pline and more.


Quick fix. Isolate the border layer and use the boundary command to create a new pline. Erase the old, add the new to the srf def.


Readup on the MAPCLEAN command. This will fix many geometric errors in the linework.

John Mayo, PE
IDSP 2014
Win 7 64, Xeon ES165@3.2Ghz,
64 GB RAM, Quadro K4000 (x2)
*Expert Elite*
Posts: 1,669
Registered: ‎06-03-2011
Message 3 of 3 (1,272 Views)

Re: Illegal (self-intersecting or non-closed) Boundary Polyline

05-02-2012 12:13 AM in reply to: jmayo

@ Mramseur

When I have a self-looping boundary (apparently closed) I always _EXPLODE it up to line level, then I _FLATTEN it to the ground, then a deep _MAPCLEAN in order to join automatically the chunks, finally I _MOVE it to the original height.

It takes some minutes, but satisfaction is 100% guaranteed.

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