Traumflug
Visolate generates cut paths over traces, and more... strange paths
When I read about this tool on the RepRap wiki, I had some high hopes for it. But I just tested it, and for me it seems to generate a totally wrong GCode path, with cut paths crossing traces and more random strangeness. I used the released 3.0.1 version.
I've uploaded my test gerber file to: http://daid2.mine.nu/~daid/V-USB.GTL
It's indeed a mess which is produced here. Thanks for bringing this to attention.
Which application did you make this Gerber with? I'd need a much simpler testcase (one or two pads) for debugging.
I've just tested with release 2.1.6, your file works reasonable there. This may help until this one is debugged.
After bisecting a bit, part of the problem is at least how square and octagonal pads work out.
In Visolate 2, a cone was drawn around the center of the pad, approximated by a 16-segment pyramid. Visolate 3 draws a pyramid with a flat top and with 16 segments for a circle, 8 segments for an octagon and 4 segments for a square. If you have a number of such overlapping low-segment-count pads in an exactly aligned row, some of the pyramid sides neccessarily overlap exactly, making the surface flicker.
In other words: using round and oval/obround pads should work a lot better.
I created the design with eagle. It was just something I had laying around to and decided to see how Visolate would work with it. I had no intention of actually milling this exact design :) but I was surprised at the results.