Material in meshes

Hello !
I am new in Revit Dynamo, and i have a problem about material in meshes.
I already try to put color or material in a mesh but i can’t and i don’t know why !
I can upload my mesh without material in my revit construction but it’s not “pretty” without a color or “material” beacuse we can see the line of the mesh.
i think is because it’s not possible if my mesh is not a solid/mass/volume, no ?

Thanks a lot for your help !

i was thinking maybe it’s because my mesh need to be in a family to be a mass, a volume or something but it’s didn’t work, any idea ?
The yellow message say “Avertissement:FamilyType.ByGeometry attend le ou les types d’argument (Solid, string, Category, string, Material, string), mais a été appelé avec (double, string, Revit.Elements.Category, string, Revit.Elements.Material, string).”