Why does Offset generate only one curve?

Hi, I asked this in the GH forum but I realized is it equally relevant to Rhino. I still haven’t found a solution to this besides using Clipper plug-in.

Here in the preview of the offset one can see that two islands are generated. But when I confirm the offset only one is…

I can use the no trim option within the offset command, but that just generates the whole previewed curve, which is not what I want. It basically adds an extra step of manually trimming curves…

This is the result I am looking for in one click:

you can no trim, then use curve boolean to clean it up.

That is not what you are asking, but it may be the simplest path. The self intersection is the issue, rhino appears to not be able to tell what to do with the curve past the self intersection.

you could script this, and offset, then curve boolean on one button.

This has been the case ‘forever’ - the item is still open on the bug tracker. For now you can get the two inner curves by repeating the command and clicking on a location on one bluge then on the other - not ideal but better than trimming.