Hi OSIAS,
This is still the case. When using a Multi-sub-object and using separate materials like that it is using a draw call for each material.
I don’t think you would be too hard pressed with optimization by using this single model as a multi-sub-object, especially if it’s a main focal point or a weapon that is used.
I’ve not brought a lot of my models and textures over to UE4 yet but this is something I’d like to look into as well. One of my projects had a lot of hospital equipment. The gurney I made would be a good test for me to see what’s the best solution for this as it had a cloth/rubber padding and metal frame.
I’ll have to test this out when I get home and can look at those assets.
Great question though, especially for new users!
Tim