Intersecting List structure issue

Hi there, i can’t imagine to do that.
How can i intersect only the first item of line with the first item of surface? just to avoid the case in the 3D background.

You may need to filter by distance as well, before checking for intersects. Hard to tell without seeing the rest of your graph, can you post an image of more of the canvas?

Sure my goal is to when an architect move the wall try to set new location read the boundarie of the room, i had problems with element boundaries node from Archilab and Spring and have to transform geometry.
Then my goal is to read the current family vector reverse them and “try a raybounce” by a line but this line the distance is aleatory so in some case (up case) the line intersect with a wall in other room.

If you think there is a best way to achieve that please let me know.