Normal maps.

The only thing that could make Unreal Engine 4 better is if this features was concluded:

A feature that makes the player able to import a difuse texture and press “Create normal map” Forexample you could create the normal map right out of the difuse and adjust the bump etc right in the material editor. Would spare so much time out of modelers.

It sounds like DeriveNormalZ may be what you are looking for.

Is this a plugin for the udk “unreal 3”? And if so, is it for unreal engine 4?

It’s a node in the material editor.