How to add new channels to materials?

Hey guys,

I’m currently creating a (fantasy) character using the photorealistic character workflow. I’m using Skin, hair and eye shaders provided by a Paragon character I got from the marketplace and just replaced the maps to suit mine. However, I noticed that the Skin shader doesn’t support metallicness (I need it because part of the bust’s texture is scale armor). Also I’d like to make his pupils glow (I’d just use the Iris map for the colors). My question is how do I add those channels? It’s probably not even hard, I’m just still new to Unreal. I added a screenshot of the shader node network for the Skin shader. The one for the eye is much more complex, though…

I’d be grateful for any help! Thanks in advance! :slight_smile: