Get interior regions and exterior polycurve of a curve network


I am working on constructing a street network from centrelines. Following this topic, I managed to process the offset for the street network in parallel (meaning my script now computes multiple offsets and retrims at once).

Here’s the result of the script:

I was wondering though, does anyone have an idea on speeding up the region union part? It is by far the heaviest calculation and it needs to be done for several sets of curves. This means I lose the real-time preview I had up until then.
Would it for instance be possible to splitting the curves at the intersections and getting rid of the interior curves?
Interior regions of curve (76.3 KB)

Polyline Offset from clipper seems to do the job !

Unfortunately, Clipper only supports polylines.

It’s easy to convert though with the Curve to Polyline component:

But I am working with lots of splines on this one that I prefer to keep.

Yes, but Mc Neel is working on a new Offset for Rhino WIP, hope it will as good as Clipper. I can’t find the other discussion on subject but there is this one.

For a better performance you can play with tolerances inside Rhino. Grasshopper dosn’t show this option but it must choose Rhino tolerances