Well, plain Offset as it exists is a 2d operation - it requires a plane - if you want something other than that, you’ll need to be pretty specific - a ‘true’ 3d offset is not really an option - that’s a pipe. There needs to be some reference. So, for now, there is OffsetCurveOfSrf - not a 2d operation, OffsetNormal, which could, I think get a Direction=Normal/Tangent option like
Fin has - To get the curve I think you want use
Fin, Direction=Tangent and dup edge. If that gives the desired result, then I think
OffsetNormal can no doubt be tweaked to work tangent as well - my guess is it is using exactly the same code as
@eobet - in case it helps, here is an updated ‘FinTools’ that optionally returns curve, surface, or both - maybe it does something useful in this context.
FinTools.py (21.4 KB)
To use the Python script use
RunPythonScript, or a macro:
_-RunPythonScript "Full path to py file inside double-quotes"
FinTools.rhp (35 KB)