Imported DXF from AutoCAD: Separate Shapes Merge Unintentionally in KLayout

Comments

• Matthias

  July 5

  Hi @klxdzh,

  There is different settings available to achieve different results. In order to get support, you should supply a sample file and explain what results you intend to get.

  A very basic issue of DXF is that is does not really feature "filled" objects. Instead, DXF supplies lines in various flavors and KLayout needs to convert them into "filled polygons". There are different strategies, but the first step is always to stitch segments into continuous lines. If the lines in your drawing touch, KLayout will form larger polygons and it has some preference how to do this. I assume this is the case here.

  As there is not single solution to the problem, I think you're hitting a basic limitation of the DXF format, when it comes to translation to GDS.

  In any case, it's the polarity that matters - i.e. the part that is filled vs. the part that is not. As this is the crucial property of a photomask, the result is correct, if the polarity is. Coherence of polygons is a low priority requirement for the DXF to GDS translation.

  Matthias
• dick_freebird

  July 6

  Seems to me that a literal, polygon for polygon
  translation ought to be an option. I'd guess that
  the problem is vectors that are "loose", with no
  "bundle" to decide which merge and which do
  not in subsequent steps?

  Perhaps this is a source-DB thing (too many free,
  loose segments?) and wants some "surgical
  intervention" there, like to make repeated loose-
  vector structures into hierarchy objects?

  But then maybe it's a klayout hierarchy handling
  thing, like a "flatten 'em all" step that busts any
  incoming hierarchy before it can be used to
  determine "polygon membership"?