Just a tiny little addition: to download the component @greevedogg mentioned , one needs to do these two simple steps:
- Register to the Grasshopper forum.
- Join the Milkbox group.
If these two steps are not fulfilled, then you won’t even be able to open the upper download link:
http://www.grasshopper3d.com/group/milkbox/forum/topics/boolean-split-surface .