I have a group of vector files that I intend to convert to "DXF" format. But after the conversion, only contour lines(white lines in the red polygon) are not displayed in Autocad. I read some related Q&As in this site but could not get a satisfactory answer. Does the problem stem from the elevation data or intersection with polygon or something different?

Regardsenter image description here

enter image description here

  • What is your shapefiles? Are they polygons or line. Is this shot from CAD or from QGIS. I tend to use Grass for conversions of this kind.
    – Ger
    Jul 2, 2015 at 11:19
  • The problematic shapefile is "line(the contours on red polygon)". The shot is from QGIS.I haven't used grass before
    – lunata
    Jul 2, 2015 at 12:01

2 Answers 2


Okay, based on the comments above. I think your first problem is that your white lines are gaps between the polygons.

I would start by establishing what the subject is. I.E. is it lines on a polygon or a polygon with loads of other polygons.

I would try to convert polygons to lines using Vector>Geometry tools>polygons to lines.

If this works and you are no presented with a shapefile of the line, with no red shading, then all is good.

Its a simple matter of conversion to dxf. you can try right click the file then save as, and select dxf. this SHOULD work. However, as i am used to using Grass, as the other method used to not work, i would follow this Video...it is really simple.


  • I converted the polygon to line however the result isn't changed (I have added the result as image on question part).
    – lunata
    Jul 3, 2015 at 7:13

I defined the datum of contour lines by myself. However it was not defined by CAD programme. So I set the datum same with other vector files and offset the contours. Then I converted to dxf again. As a result, the problem has been solved

  • is the 2nd picture the solution??
    – Ger
    Jul 9, 2015 at 10:44
  • No, it isn't the solution. It is the display of the problem. Autocad does not support the "on the fly" like GIS. That was the neglected point
    – lunata
    Jul 10, 2015 at 11:25

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