I am trying to extrude the generated objects to get a gable roof.
The objects are allready split in half to extrude the polyline.
Especially when it come to corners with multiple polylines I am not sure what to do.
There are aspects of the puzzle you presented that made it look easier than past efforts. Unfortunately, there are hidden aspects that made it much more complicated than it should have been, requiring the yellow group (below) to clean up extraneous lines that caused trouble for new code (white groups).
Joseph_Oster is the master for sure. His solution is very elegant. Every time I look at his solutions I learn something. I took a run at this in a different way. Looking at just one of your “houses”. So here is a really basic way to get there on just one. Gable v1.gh (11.4 KB)
Here is a clumsy effort to handle one building/roof at a time. It depends on knowing the gable ends are always on the edges that are 6 units long, which of course is not a general solution at all. And TweenCrv fails to find the correct midline on two of the four corner buildings, which is bad!