I just realized that if a polycurve is composed of curves which are tangent, the result of “FitCrv” is a single curve, but multiple curves otherwise.
Why do I discover this ater 20 years of using Rhino ?
Here’s the online help for this command : no word on curve merging.
And why isn’t there an option to either output a single curve or not ?
I’m sobbing over the useless hair pulling from all these years…