Print has ridges that are not found on the original file

[reinerbenz]

I was wondering why the line came out after the output

I’m not sure whether this is the case here, but that sort of artifact is common when you have two shells which touch, but aren’t unioned together. Is it possible that the bottom of the low part of the building is coplanar with the flat area around it? If this is the case, then what’s probably happening is that because of numerical precision in computing the two planes, the slicer sees some scanlines as being part of the flat area and neighboring scanlines as being part of the small building. T…