Epic's Open World demo collection is up and available right now on the Unreal Engine site, offering Unreal Engine 4 users a selection of realistic assets for use in their projects, as created by the uber-pro's at Epic.
The assets in the demo were created using photos of objects in the real world, with bigger objects made with a process called 'photogrammetry', which Word doesn't seem to think is a real word. Specular, rough and normal maps, LODs and collission meshes are added, so all of the assets are good to use in any Unreal 4 project you might be working on.
It's another step in Epic's plan for total world domination by giving all of its Unreal 4 engine/assets-related items away for free.
You can see more details of Epic's photo-reconstruction in its presentation from GDC, which, handily, I've embedded right here: