Apply a pattern to one of the surfaces of an import object

[Cristina_Machin]

Hi, I want to apply the red pattern to the upper surfaces of the imported stl file, I have tried several methods but any of those work.

helmet for pattern.gh (17.7 KB)
helmet for pattern.3dm (626.2 KB)

[Quan_Li]

helmet for pattern Edited V0.gh (414.2 KB)

[Cristina_Machin]

Thank you very much! Could you explain me how you came up with the solution?