Offsetting several curves at the same time

I want to offset/thicken the grey curve into the red curve (the red curve should be a series of closed curves)

The issue is rhino cannot offset more than one curve at a time, and offsetting a self intersecting curve produces weird results. (offsetmultiple cannot cap or do bothsides)

Using pipe and then section/contour can work, but i prefer not to use this workflow.

Is there any way to do this in rhino/grasshopper?

Thanks, Kayne

I dont mind the capping style, it can be curved or flat

Offsetting Complex Curve.3dm (93.7 KB)

how many of those curves do you have ?
what are you use them for ?
ist this a one-time approach or a tool that needs robustness and performance ?

quick and dirty:
do it in illustrator - your offset is half the line thickness - create the outlines, combine the curve.

manually:
for less work join curves
offset both sides cap style round, important set trim to no / turn it of.
(a pity this is not possible with offset multiple)
Curve Boolean - all Region - unselect inner areas manually.

after joining and offsetting:

curveBoolean AllRegions - with one additional mouse click to get this inner section:

grasshopper
… i would recommend to code / script it.

hope this helps - kind regards - tom

have a look at Clipper2GH | Food4Rhino

Thank you, this plugin works for me