Loading multiple GDS files with individual layer properties files?

Hi Matthias -

is it possible to load multiple GDS files (in different panels of the same klayout session) with individual layer properties files (one layer properties file per one GDS file)?

If I do this:

klayout file1.gds -l file1.lyp file2.gds -l file2.lyp

It seems that klayout uses the last lyp file for all panels/ GDS files...

Thank you!


  • Hi,

    There basically is just one layer properties file, but it can contain layer properties for multiple layouts.

    If you load two layouts and save the layer properties, you will see layers with suffix "@1", "@2" etc. If you load such a layer properties file on a two-layout panel, you can assign different layer properties to the different layouts.

    Is this helpful?


  • Hi Matthias -

    We tried to follow your suggestion - and could not achieve what we want - the saved lyp file contains layer properties of only one layout/panel.

    However, using session history, we can save multiple lyp files into one session file, so this should work for us, for the time being...

    Thank you!

  • Ok, maybe I need to be more specific:

    1.) Load two layouts into the same panel
    2.) Then assign the layer properties as you need them (@1 layers are for the first layout, @2 layers for the second)
    3.) Save the layer properties

    This recipe is working for me on 0.25.3.


  • Hi simg: You need to be a bit careful with this. The layers are later used for mask making (in general, using Boolean operations) and so certain GDSII or OASIS layer numbers are combined to make masks. So you really can't merge GDS files which have different layer definitions easily and get a good mask. For simple cases you can check by eye that there are no conflicts, but for entire technologies this is very difficult. So I would stick with one set of layer properties for all GDS files you are merging. The way I do it is that I first define all the layer properties (by translating a layer map file, for example), and then I read in the layout files with this map, and then I check that no new layers were generated. For new technologies getting this right is extremely difficult in my experience.

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