Region Union not working in all (very similar) cases

I have a definition where I have two very similar cases, but the region union only works in one of them. I guess it has something to do with the input geometry but I cannot figure out why one works and the other does not. Can somebody help?regionUnionCase.gh (14.1 KB)

Why would you want to union those anyway if you basically just want to keep 1 of the input curves?

My guess is that it has something to do with the fact that you have 2 shape which are very similar but have a different degree of curve.

This works:
2020-09-07 12_38_26-Window

I don’t know why… maybe because my rhino is set with 0.0000001 precision ?

Ahh, I was hoping for something better which would not simple ‘do-something’ --> ‘do-something’^-1 thereby just slowing down my def. Still hope that somebody can figure out what is going on. But thanks :slight_smile:

There are cases in my definition where it’s not the case that the two curves are almost the same…

I suspect it really depends on how your initial geometries were created…

Anyway, as solid boolean operations is difficult when there are overlapping and tangent surfaces, the same thing is when you try to do region intersection functions on overlapping and tangent curves.

Best would be to just try to avoid that from happening.