Whats the best way to apply different materials so the same mesh?

Rhino Rhino for Windows
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#1

Do I need to run ExtractMeshFaces to then apply a material or…

#2

I usually use splitmesh to break it up and then assign normally.

#3

Thanks Kyle, I was needing something along the lines of selecting faces (topography with different ground materials). Thought maybe it was possible without extracting faces.