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I'm experiencing problems when exporting a polygon feature class:

  • The original feature class has no overlapping polygons (as shown below, image 1), it's been topology checked, so no potential errors here.
  • I copy the relevant field from my feature class to a text field named "Layer", in order for the attributes to be available in the DXF.
  • I export to DXF as shown below (image 2)
  • the DXF produced contains overlapping polygons for all original features that were island-like (fully within another feature) as shown below (image 3).

Is there a way to prevent this from happening?

original_FC

exportmenu

CAD_features

I'm using ArcGIS 10.3 with an advanced license.

  • 1
    Arcgis hopeless with export to cad. Perhaps try arc2cad, they have trial versions. Is split in multiple triangles an option, can you dissolve them in cad? – FelixIP Dec 6 '17 at 18:22
  • @FelixIP thanks for your input - problem is, i'm GIS-user only and need to convert the data for a client... i'll check the tool! – dru87 Dec 7 '17 at 7:02
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I do not think there is a way to stop this from happening. From my understanding of CAD and the CAD Formats. A GIS Polygon is "seen" as a hatch in AutoCAD (as an example), CAD uses closed Polylines.

I.e: If you have two non-overlapping Polygons in a shapefile and convert that to a CAD Format. The polygons are seen as having 3 hatches. The inner, the outer and the combined. The converted CAD file will therefore show 3 polygons instead of 2. The Polyline created from the Shapefile to CAD Conversion will show the correct alignment of the Polylines from the shapefile.

If there is a way, I would love to see it, but I don't think its possible.

  • Just adding to this. I played around with conversions in different software packages. It is a CAD thing, there isn't a work around. If it is for the clients consumption in their CAD software, they wont be able to see the overlapping polygons..because in CAD it will be a closed polyline. If the client isn't happy...I don't think there is anything more you can do. – Keagan Allan Dec 8 '17 at 9:38
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in that case, I have a better workflow: 1.convert the polygons to polylines. 2.export to CAD and import to GIS as polylines too. 3.in the arcGIS use the tool feature to polygon http://pro.arcgis.com/en/pro-app/tool-reference/data-management/feature-to-polygon.htm

than won't have overlapping polygons.

  • thanks for your second solution / workaround. i guess this is what i'll have to do in the future. i marked another answer as the correct one, because it answers my question a little better (since i asked about a specific workflow). your solution is a good workaround though. – dru87 Dec 11 '17 at 6:44
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yap all the so-called polygons in CAD format (which are just closed polylines) are simple-polygons meaning they cant have holes in them? there is a workaround for something called a donut polygon.

https://support.esri.com/en/technical-article/000004852

  • thanks for your answer. i do not have any overlaps in my original data. your proposed workaround isn't really an option for my problem, since i'd have to manually clip a few hundred polygons. – dru87 Dec 6 '17 at 14:52

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