Incorrect. Content from previous Unreal games can be imported into other Unreal games.
You cannot port UT content into Bioshock or vice versa, and you cannot use UT content in UDK or UE4. You also can't use Gears content in anything other than Gears, but that never stopped anyone... :/
You cannot port UT content into Bioshock or vice versa, and you cannot use UT content in UDK or UE4. You also can't use Gears content in anything other than Gears, but that never stopped anyone... :/