Export of contours to DXF file

[Kokoi]

I have an issue with Contours exported to DXF file. When it is opened in Autocad, the units of exported file are correct in Z direction only. The polylines in the XY plane are a hundred thousand times smaller than they should be. In order to fix it, I have to create block from polylines and set up its scale in X and Y direction to 100.000. The Z axis scale remains set on 1. Than the block decompose again and that's it.

The second issue is that the polylines are exported as 3D polylines. This results in extremely large DXF file. In fact I don't understand why 3D polylines are used. All points at the polyline have the same hight and 2D polylines would be enough. In order to get the file smaller, it is necessary to use Autocad Civil and convert all 3D polylines to 2D polylines.

Am I doing something wrong or do you have any tip how to get the correct DXF file with contours in a easier way?

[Alexey Pasumansky]

Hello Kokoi,

I assume that the coordinate system that you are using for export is WGS84 which uses degrees as a units for X and Y coordinates (Longitude and Latitude), while Z is in meters. But Autocad is treating all XYZ values as same units, which lead to the observed issue.

I recommend to use a projected coordinate system for export (like some UTM projection related to the area) if Autocad doesn't support degrees units for X and Y.

[Kokoi]

Hello Alexey,

thanks a lot. It really helped. The DXF export must to be set on projected coordinate system. Now it works well.