Split with Brep not working as intended with set of closed curves


I’ve run into an issue while trying to split a set of closed curves with a plane. The output consists of only partially split curves.

Interestingly enough, if you move the reference curves the output will vary. You can even get all of them to split, but moving the curves is not something I plan to do in my usecase.

Only just starting get a grasp of Grasshopper so I’d appreciate some help or advice to remidy this, thanks!!

01.3dm (116.3 KB)
01.gh (8.5 KB)

It seems to be a bug. If you explode and rejoin the curves it works.

I remember reading a post the other day about a closed curve that wasn’t quite acting normally, and this was also the solution.


Hi @j.goerke96,

I’ve tested this in Rhino 6 and it works as expected.

In Rhino 5, try moving the seam of the closed curves off of the plane.

– Dale

This worked, thanks!

The issue happens regardless of seam position it seems. Curiously the amount of correctly split curves changes with increased spacing between the curves. It seems very arbitrary.

Sadly your solution only happened to work with my current configuration. If you increase the number of cross sections the function goes awry again.

02.gh (15.7 KB)

Changing any of the sliders in this scenario makes it resemble a random culling pattern again.