Cause of 3D Polylines in DXF Export?

Dan Anderson

I'm importing NHD data and exporting to a DXF file. I'm then opening the DXF file in a drawing program and losing some of the objects. The objects that are lost start like the following in the DXF file:
POLYLINE
8
WM_T_MultiUse
70
8
66
1
62
3
39
3
0
VERTEX

I believe (not being familiar with the format) the " 70\r\n8" indicates a 3D polyline. If I delete this code I get the object in the drawing program.

I've done the search by attributes list and don't find anything (and no elevation value) that is only common to those objects that don't work.

Is there a way I can get GM to generate 2D polylines?

global_mapper

It sounds like for some reason your other drawing program does not like 3D POLYLINE entities. What you can do to get 2D entities out of Global Mapper is to first export your data to another format (say Shapefiles) and make sure NOT to check the box to export elevations for each feature. Then, load that Shapefile (which should no longer contain 3D features) back into Global Mapper and export it to a DXF file.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

Dan Anderson

Thanks. Export to shapefile and re-import works.