When opening DWG/DXF files to a model, in the third step the option appears Merge points closer than. This is the size of the gap, which the program will remove when opening the file and combine the segments into a whole.
But did you know, that in the command repair sketch również jest możliwe określenie tolerancji dla przerw w szkicach – Showing gaps smaller than.
Well, by changing tolerances, the program will show micro breaks or ignore them.
It's also worth remembering, that open sketches are extracted as default thin wall. And a closed contour fills the interior with shadow (with the option enabled Shaded contours sketch).