The open world demo that Epic games showed off at GDC to showcase their Unreal Engine 4 technology has had all of its assets released completely for free (as long as you have an Epic account), meaning they are now fair game for you to mess around with, should you want to.
“For larger assets such as rocks, ground tiles, cliffs faces and tree trunks, reconstruction was performed directly from photographs using a process called photogrammetry,” Epic said. “These assets were then put through a proprietary ‘de-lighting’ process to make them suitable for use in any lighting scenario. Specular and roughness maps where then created to take full advantage of Unreal Engine 4’s Physically Based Rendering architecture. Finally game-optimized assets were generated with normal maps, LODs and collision meshes.”
“For vegetation such as flowers, bushes and grass we used color calibrated reference photography shot in the field to more accurately model and texture these assets.”
Weighing in at 6.3GB, the asset pack should help aspiring game developers get something off the ground. You can download it from here.