How to do -> surf trim

Hey guys,
how i can trimm a surface with a line or an intersection. i cant find a tool for that or is there any script??

thx a lot

You can use [Surface Split]

I should add that the reason it is not the same as Rhino is that during the Trimming process it removes the unwanted part because of where you click.
As there is no user interaction in GH you have to come up with another criteria for selecting which resulting surface to keep. It could be based on size or location i.e. inside a bounding box

thx , but yes i need to disapear every second surface i have trimmt. i have a lot of vertical projected curves on a surface and now i want to trim every second of this splitted surfaces. i tried it with a cull (pattern)
but doesnt worked

That is the correct approach, can you post the results for me to look at?

trim surf.3dm (64.2 KB) trim (17.6 KB)

You need to flatten the input © Surface Split

thx a lot

…,but why there are so many surfaces in the same place or how can i get only one surface per cutout?

I don’t understand. The output of the [Cull Pattern] component is 22 surfaces one for each strip. There are no duplicates at this stage. You then go on to do something very strange with the [Split List] component which is probably where you introduce the multiple instances of the surfaces.
You should probably use a [Dispatch] component if you want to keep every surface but split them up.