The shape with Arc was convert to trapezoid after open the gds file ?

sunny.etic

I have some gds file which contains some rectangle with arc at its corners. When the gds file was open by Klayout, it was automatically deccompsed to many small trapezoid. Though can be merged by Tools/layer/Merge function of Klayout, is there any options to keep the original polygon structure not to be convert to trapezoid after open the file in Klayout ?

Matthias

Hi Sunny,

that is pretty strange. KLayout will never modify a Polygon on reading. So it must have been decomposed already when you created the file.

How was that file created?

Matthias

sunny.etic

Thank Matthias's reply. The data is stremaout from Virtuoso cadence. I will try to adjust the Max vertices to streamout again.
By the way, Is there any script or tools to do merge for all layers in the layout instead of do it layer by layer at tools/layer/merge function ?

Matthias

Hi Sunny,

I was guessing so. But I'm not aware that Cadence does not decomposition. Maybe the maximum number of polygons is set to a very small value.

Regarding the merging: you can do that with a DRC script. The basic scheme is

# merge layer 1, datatype 0
input(1, 0).merged.output(1, 0)
... continue for other layers ...

The script can be written such that it will iterate over all layers automatically:

layout_obj = layout.layout
layout_obj.layer_indices.each do |li|
  l = layout_obj.get_info(li).to_s
  input(l).merged.output(l)
end

Disclaimer: I have observed some instability when running that script twice. I'll have to look at that more closely.

Please also note, that merging will flatten the layout and remove all text objects since they don't contribute to polygons.

Matthias