Question about "Link Material to Object" button

Hi, I have a question for an experienced blenderer.

In the material buttons panel, in the “Links and Pipeline” window, there are two buttons, one that says “OB,” and one that says “ME.” Apparently, these two buttons allow you to link a particular material to either an object or its mesh. Through some experimenting with the OOPS outliner, I have discovered that it is actually possible to assign two completely different materials to an object, one to the object, and one to the object’s mesh.

What is the purpose for this? What is the difference between assigning a material to an object or its mesh? I always link a material to the mesh, and its not necessary that I know what the other option does, but I was curious.

Thanks in advance for any help.

it is actually possible to assign two completely different materials to an object, one to the object, and one to the object’s mesh.

Actually no and even your sentence contradicts that: “two material to an object… one to the object…” A material datablock can be linked to what I call a structure datablock, (mesh, surface, meta and the likes: I forgot the proper name but someone will remember), or to an object datablock. When a material is linked to the object datablock it is the one which always shows. When there is no material linked to the object datablock then the other one linke to the structure datablock shows.

I use the OB button in two cases:

  • when I want one or more of a set of instances (copies made using Alt+D) to have its(their) own material.
  • when I intend to change the structure datablock linked to the object datablock while making sure that I won’t change the material of my object. This happens because I always study my compositions using rough approximations of my objects that I replace by more refined ones later (simply by picking them up in the ME drop list of the “Link and Materials” panel of the Edit buttons (F9)).

I look forward to learn other uses.

Jean

Hey, thanks, IamInnocent, that makes a lot more sense now.