Master Materials are extremely powerful because they follow a parent–child (inheritance-based) structure.

You build one main “parent” material with all your features, and every material instance you create inherits those settings, as well as the ability to manipulate custom parameters for each instance without modifying the parent.

For the lobby, I wanted an efficient method, to transition all window materials from the “day” to the “night” setting, without assigning any materials at runtime.

To achieve this, I used a master material along with a Material Parameter Collection (MPC), which is essentially a global list of scalar and vector parameters that can update at runtime, allowing materials to transition or change dynamically.

Insert gif of mpc here…

Here are some valuable tips when creating master materials in Unreal Engine:

• Keep modularity in mind. Don’t hardcode image textures, or material attributes as this defeats the purpose of a “parent” material. The parent material should not be used on it’s own, instead it should be replaced with material instances.
• It’s okay for it to be complex. Master Materials are the foundation of complex material setups. Take the time to handle edge cases and design them to be as flexible and customizable as possible, so your materials can adapt to a wide range of assets and scenarios.

Insert video here…

Again, I am still learning, this is just what has helped me. If anybody has any feedback, reply below.