Invalid brep with surface morph

Hello, Can you tell me how to apply the following pattern on a curved surface, I used surface morph, it actually gives the wanted result but as an invalid B rep, any explanation would be helpful. Thank you.
invalid brep.gh (50.9 KB)

You can avoid the invalid brep condition by using slightly less than the full ‘U’ domain.


invalid brep_2020Oct27a.gh (50.1 KB)

That solved it indeed. thanks

The slider can be set very low, less than 0.001 to get a closed brep. Negligible visually as long as you remember you have created a “hole in the boat” so to speak. In some cases, that can matter.