Is it possible to join several static meshes in the UE4 scene into a single static mesh with 1 material to reduce number of draw calls?
You can do it using Instance Static Meshes in a Blueprint, but otherwise you would have to export it to UE4 that way.
Well, that’s what I do now. However, there is Quake/Doom3/Hammer map import plugin that imports .maps made for Quake/HL2/Doom 3 into UE4 and when importing into UE4, it creates geometry that isn’t suitable for mobile VR (too many meshes / materials, thus too many drawcalls for mobile VR). I recall UDK had a tool that would combine meshes and bake textures to make 1 single mesh with 1 texture and 1 material. I am guessing for whatever reason that tool didn’t make it into UE4
In the 4.10 you can go to: Edit -> Editor Properties -> Experimental -> Check the Actor Merging -> Close the Window -> Go to Window -> Merge Actors -> Select the actors in scene set the settings you want and create the mesh -> Done.
*The static instances aren’t here by default to set in map editor atm.
Something like this would be cool having in UE4: http://www.texturebaking.com/features-benefits/
Merge actors is the best bet.