Offset curve

Grasshopper
1

Hi,

I wondering if this is a bug or am I not seeing something obvious…
The offset component in GH seems to ignore the input plane. offset.gh (4.1 KB)
Black lines are what are expected, tested in Rhino, and red lines are the results from the component.
I haven’t encountered this issue before.

offset
offset1436×696 72.7 KB

2

The curve is planar, so it will offset in plane of the curve. If the curve was not planar, it would use the plane input.

It seems like maybe you just want to move the curve, not offset.

3

Thanks, I understand that the curve is planar and the default may be offsetting in plane. But I would think that the input plane will override that default, which is what happens in Rhino (where you’re able to switch in plane on/off). I could, of course, move the curves in this case, but this is a part of a larger script where the curves are not necessarily always planar.

4

I guess I have never expected it to work in this way.

You could possibly make an exception, and filter for curves of this type and use move instead.

Alternatively, I had a look through the RhinoCommon methods, and rhinoscriptsyntax for Python, the closest I could find to achieve what you want was OffsetNormalToSurface (https://developer.rhino3d.com/api/RhinoCommon/html/M_Rhino_Geometry_Curve_OffsetNormalToSurface.htm).

Maybe this could work for you.
offset_V2.gh (7.8 KB)

5

flagging this as second person to hit this as a bug. I have a not straight bridge with a sloping parapet top - so I wanted to offset the line of the parapet along that sloping plane, not the plane of the bridge curve.

image
image992×502 22.3 KB