Offset Curve Failure

I’ve been having a lot of trouble with the offset command in Rhino & Grasshopper lately.
I know that many people have mentioned problems with the offset command here:

And I know it’s not an easy problem to solve, but I wish GH would at least let me know when an offset fails. In the attached definition, two closed polylines go in, nothing comes out. No error messages or warning.

The workaround is to explode the lines, offset, trim the results, and rejoin, but that doesn’t work in every case.

The attached rhino file also fails with _OffsetMultiple even though its only two rectangles.

I ran into this problem using Rhino.Inside.Revit, as you can see in this video:

It’s more of a rhino/grasshopper issue, but the fact that no warnings were produced made it tricky to track down. (8.8 KB) OffsetCurveFailure.3dm (33.4 KB)

Thanks to everyone at McNeel!


I should have mentioned, this is using the WIP, latest release. This all works fine in Rhino 6.