Different results when calculating curve offsets

Scripting
1

Hey there,

so i stumbled again upon this strange behaviour in RhinoCommon using Python and i`m wondering where it is originating from.

When offsetting the same curve with Curve.Offset or Curve.OffsetNormalToSurface the results are different on a suprisingly big scale. The underlyling surface is not really complex. Can somebody explain to me what is happening and if there is a fix ?

Attached i’m sending you the script and the geometry.
CurveOffset_Sample.3dm (95.9 KB) Curveoffsets_3ax.py (3.0 KB)

Thanks

Patrick

2

Hi @patrick.jaksic,

The results of the two offsets should differ.

Can you post a 3dm file with a surface, a curve on the surface, and the results you expect (e.g. run OffsetCrvOnSrf)?

Thanks,

– Dale

3

Hi Dale,

somehow i don`t understand how the offsets in this case have different results. Attached i am sending you a Rhino file and the corresponding script.
In the .3dm file you can find the face for the Offset on the “Face” Layer and the curve to offset on the “Base Curve” Layer. The other curves on the “Offsets” layer are the offsets with the different methods. The black curve on the Offsets Layer is the one made with the NormaltoSurface method.

Patrick

CurveOffset_Sample_v2.3dm (43.5 KB) Curveoffsets_3ax_v2.py (1.3 KB)

4

Hi @dale,

did you Take a look at the Example ?

5

Hi @patrick.jaksic,

I did - sorry for not replying earlier. I’ve logged an issue so I can look into this further.

https://mcneel.myjetbrains.com/youtrack/issue/RH-62837

– Dale

6

Okay no problem.

Thanks