Hi Steve, and then you get that kind of odd "broken edge" look in that case because the generated pieces were close enough within tolerance to get joined together.

The sweeper attempts to join together the different generated surface pieces that are created from segmented rails.

If you measure the distance of the broken looking spots, you should find that they are less than 0.005 units apart, so that allows them to be joined despite having that much of a gap.

That might be another good thing to handle specially if the rail was only made up of lines - the joining step could be disabled for that case since it is really meant to join together the results from G1 segments which do then connect up nicely.

- Michael