How to force trim to always pull curves to its surface?

[eobet]

@eobet

A projected curve loses one level of continuity, so if you trim with G2 curves, you get G1 edges. If you trim with G1 curves, you get G0 edges.

@Pascal is this not true for the underlying mathematics in Rhino? @John_Brock you like to quote the NURBS definitions to me, do you know? @bobmcneel ?

I might embarrass myself here, but what the heck:

G3 surface/curve/edge used to project normal (pull) trim a surface, always yields a G2 edge. This is predictable. This is set in stone.

Is there a setting I’ve missed in Rhino, or why does this happen? What am I not understanding about Rhino here?

test.stp (17.3 KB)