Multiple materials on a single object?

Question

I have many objects all with the exact same base metallic "surface". Some of the objects require small simple variations in bump and displacement.

Is it possible to have color, metallic, roughness, etc. (most of the principled BSDF) in a single easy to change material and then have different materials for various changes to bump and displacement?

Could this be done using an addon or "data transfer" of some kind? A modifier? Or maybe something I haven't learned yet within Blender that would accomplish this? Basically some way to "layer" or "add" materials. The same metal material for 10 objects and then each object has another material adding bump or displace texture.

Another comparison would be something similar to "Duplicate Linked" with objects. They are the same at the "base" but you can make all kinds of changes to each "copy" but still edit the original for global changes.

I am trying to avoid having to change a common base property of a bazillion objects. I know there are other similar questions on here asking how to globally change the properties, but since I am "at the beginning" I don't need to change anything yet, and would like to start from scratch with a better solution IF it is available. I am fully prepared to simply use multiple duplicate materials.

Answer 1

Yes. The secret, as moonboots indicated is to use a node group.

Setting inside a node group are shared by all users of that group, so if you change the group on any material using it it changes on every material using it. Here's an example.

Suppose you want to share base color, metallic value, and roughness between two or more materials.

• Create a material that uses Input Nodes for those three items:

• Select the three input nodes and type CTRL–G to create a node group. The node editor will automatically set up the group so that you're editing it. In the side panel give the individual outputs meaningful names

• Type CTRL–G again to exit the node group. Your material will now look something like this:

In the side panel Give the new Node Group a meaningful name:

Now when you create a new material you have the option of including your new node group. When you select SHIFT–A to add a new group you can select the submenu Group and the group will appear there.

If you edit, for example, the roughness value in any material using that Node Group, it will change in every material using that group.

Answer 2

This always happens. I spend hours fiddling and researching something like this I reach the end of my rope and ask for help... then... within minutes I find the answer. YES YES YES! NODE GROUPS WORKS! i can save a node group for color and use it all over the place! I can link a node group directly into a principled BSDF for all the stuff I need, color, metallic etc etc and then in that material add something new for bump or displace. I can use the CRUD out of this. Awesome. I could even gang up settings for "generic displace" and link in different image maps etc etc. skies the limit.

I did a bunch of googling and searching forums but never saw anything other than a python script to update a whole pile of similar materials color attributes. I finally found it in an off topic sort of thing. Where they mention it and you the light bulb goes off over your head. works a treat.

Basically I group the base nodes in one material and then use that group node in any other material and select it by name.

I knew there had to be a way I just knew it. I should have realized how this works from all the addons that use custom node trees.