With the new Open World demo pack users of Unreal Engine 4 will get a selection of realistic assets, created by the professionals from Epic. All the mountains, rivers and plains from the demo were created using the photos of objects in the real world (Wyeth Johnson, Art Director at Epic talked a lot about it). There was a lot of photogrammetry involved. There are specular, rough and normal maps, LODs and collision meshes. All these assets are a real treasure for the developers, who wants to study Unreal Engine 4.