Bad polygon: Polygon intersects itself!

[Randall Trites]

I'm using an interface polygon to surround the areas where I am calculating volumes. I get the message: "Bad polygon: Polygon intersects itself!" Does anyone have an idea how to fix.

I'm a new user.....probably something in my workflow.

[Carl Ryan]

Randall,

Manual method is to go to the output window once that error comes up. It will show chainages (or station not sure what the reference is for Canada) of where they are intersecting. If you click on that chainage it will be highlighted on the screen. You can then split and rejoin.

You can try loop removal
STRINGS > UTILITIES > LOOP REMOVAL

You can try filtering
UTILITIES > A-G > FILTER > VERTEX FILTER

or someone else may give you a better solution

[paul hardwick]

If you don't care that you have a bad polygon you can right click on the polygon icon and select Toggle checks. This will allow you to ignor any errors, which can be dangerous.

[Tim Hawke]

Try using vertex filter to remove the duplicate points then string filter and specify a length, I just tried that and it worked for me.

[Owen Thornton]

If removing duplicate vertices does not make your polygon entirely "good", another thing to try would be removing any segment radii from the polygon, via:

Utilities=>Super strings=>Radius

I chanced upon a job last week where I found this extra step was necessary, due to a barely perceptible self-intersection. In any event, it is probably a good thing to do anyway, as tins are made of triangles, which obviously don't have arcs.