Hi rhodesy, I was able to track down the chamfer problem to a bug in the geometry library, it was overly sensitive to some slight accuracy drift (like in the area of 0.000000000000001 units) that can occur when doing operations on curves that are a bit of a distance away from the origin.

I've fixed this up for the next v2 beta, so that chamfer will be able to work on your original curves there. But it is still a good idea to work in that new scale anyway to avoid that "dense intersection curve" problem currently.


I've also tuned up the unit system scaling to also apply to background images for the next v2 beta as well.

Thanks for reporting the problems and for posting the file so I could debug it over here!

- Michael