>> we have a condition where those curves are getting progressively closer together, but it's really hard to tell if they exactly touch, and exactly where. OMG

>> we have a condition where those curves are getting progressively closer together, but it's really hard to tell if they exactly touch, and exactly where. OMG different curves and surfaces becoming tangent at a point is a huge pain. It's tempting to say that it tends to happen at the ends and can be checked for as a special case, or an algorithm tweaked based on that assumption, but then someone will find a perfectly reasonable construction that results in tangency at some arbitrary place and the problem returns.