Currently I have it set up as one mesh with 2 materials. I’m using a mask for the concrete base to prevent that from being classed as metallic.
I’d be interested to know how others might have set it up, in particular the lightmap obviously needs to be huge as it’s a very large mesh. Would you split the mesh into multiple parts and have multiple materials?
Layered materials are costly, and therefore should only be used when you need such detailed control.
I would break it into different parts and and set materials based on polygons. As it looks now, many of the surfaces could be broken up into different pieces with unique uv sets for lightmapping. The extra draw calls of having more meshes, but render the same few materials will be faster then a layered material.
Basically those 3D model elements are rather standard shapes, thus you could make this without any artistic skills. You would require to export the model than with the material nodes attached (called UV maps). Then you can assign the textures in UE to the designated materials. I doing something similar atm and i work with Blender since 1-2 weeks.
its included in the test content I believe.