Unroll surface + Joining adjacent edges together

Hello everyone! My first question in this new forum.

So, I’m working on a project on map projections that deals with unrolling geometry and joining it together in 2d without any overlaping, and I ended up with this problem:

After unrolling a surface (whether in rhino or grasshopper) is there a way to identify the edges that used to be adjacent in the original surface and join them together? It’s like some kind of nesting but I need to be able to decide which edges to join and wich not, having in mind that there can’t be any overlapings.

I will attach my surface and my desired output and hopefully someone would give me a hint.

The answer could also be a python script.

grasshopper_forum.3dm (2.2 MB)

Hello - in Rhino’s UnrollSrf command, use Labels=Yes for this.


yes, I know that is the manual way… I was trying to find a more automated one…

Hello - you can use UnjoinEdge ahead of time to force the splitting on unroll to follow certain edges- is that what you mean?


yes, I know.
I was wondering if maybe I could combine the unroll command with some kind of nesting algorithm to avoid undesired overlapping…