The Material Editor
In Unreal Engine 4, material manipulation can be achieved using the Material Editor. What this editor offers is the ability to create material expressions. Material expressions work together to create an overall surface property for the material. You can think of them as mathematical formulas that add/multiply together to affect the properties of a material. The Material Editor makes it easy to edit/formulate material expressions to create customized material and provides the capability to quickly preview the changes in the game. Through Unreal's Blueprint capabilities and programming, we can also achieve dynamic manipulation of materials as needed by the game.
The rendering system
The rendering system in Unreal Engine 4 uses the DirectX 11 pipeline, which includes deferred shading, global illumination, lit translucency, and post processing. Unreal Engine 4 has also started branching to work with the newest DirectX 12 pipeline for Windows 10, and DirectX 12 capabilities...