We need to talk about Offset

Dear Rhino/Grasshopper developers thanks for Rhino 6, many useful improvements, render, Rhinocommon functions … but there is an old subject Polyline Offset see this thread :

Are there some news about Polyline offset ?
I know Clipper is a good solution for Grasshopper and Rhino.
Update : @pascal it is not a Grasshopper question more a Rhino core function. There is a reliability problem with offset Polyline. It doesn’t work on some the cells which are simple polygon (see the picture).
The same as in Grasshopper, I used Rhino 6 and offset multiple

And Clipper solution


offset fail.gh (6.9 KB)



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Thanks for bringing this up again here. It’s been bugging me quite regularly as well.


Any response from the mcneel team? Can Clipper be incorporated into Rhino?


Still a bug. Apparently, in closed curves, it randomly chooses the inside.
I have ran into this in two separate projects.

Clipper shout definitly incorporated to GH and rhino…


Read this old but good thingy (the general case is PolyCurve offset):

anoffsetalgorithm.pdf (723.4 KB)

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Dear @laurent_delrieu,

I am bringing this old thread.

Is there a good way to offset curves that contains line and arc segments?
The issue is that clipper offsets only polylines and arcs are represented as many points.
The CNC I am using does not like many points, and I would like to have arcs and lines as a tool-path.

Is there any way to offset this polycurve with a good line-arc curve?

The paper you reference, is there a code too? :slight_smile: