array of rings

edited January 2022 in Layout

I have imported a dxf file into KLayout for the purpose of making it a gds file. The file has arrays of rings (i.e. an outer and an inner radius, nothing in the middle). But when I import it into KLayout the middle of each ring is filled (i.e. its shaded in). The circle that forms the outer circumference and the circle that forms the inner circumference are in the same layer. Is there some way to do a global difference operation to remove the inner portion? Highlighting the array and clicking on Diff in the tool bar didn't work.


  • Could you supply a sample DXF file please?



  • Hi Matthias,
    Happy to supply a file, but the attach file option doesn't like the .dxf extension. I tried replacing the extension with .txt, but no success. How would you like me to proceed?

  • Here is a screen grab of the .dxf file in Klayout and DraftSight. As you can see in Klayout the rings are filled. In DraftSight they are empty.

  • Ok, figured out how to post a .dxf file. Zip it first.

  • Hi Matthias, any thoughts?
  • Hi,

    Can you remove the hatching patterns in the original DXF? Then,...

    Different DXF reader options

    DXF reader options and the original DXF file with hatching patterns


  • Thanks for pointing out those options!
  • edited January 2022

    Sorry for this delayed reply - but actually @sekigawa has pointed out the solution. That was my suggestion too.

    I have a comment though: IMHO DXF is too complex, too diverse and too sloppy in definition to be suitable for manufacturing data. There are too many ways to represent solid features in DXF. In your case, the hatched area creates the impression of solidness, but actually it's the two circles which define the area to fill.

    After all, DXF is a format made for representing drawings, not manufacturing data. If you like to create photomasks from DXF you need to be super cautious and check the results of the conversion carefully. There is no safe way of turning DXF into filled polygon data. Also the "auto-close" option will fail if you introduce gaps small enough you don't see them but big enough for the algorithm to fail on detecting a closed contour.

    You'll find some suggestions out on the net how to reduce the risk. A little googling for example gave me this: (purely random, I am not associated with this company).

    Kind regards,


  • edited January 2022

    Hi Matthias, thanks for that responses. I think if there was a straight forward way to create circles and arcs and an array of these shapes, then jumping directly into KLayout to generate a .gds file would have been the way to go. But a quick glance at the tool bar doesn't reveal an immediate path forward. At that point the new user has to make a bet as to whether the learning curve for creating an array of circles will be better or worse than importing a .dxf file.

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