Normal mapping

Normal mapping is a way to make 3D models look more detailed. It uses a picture of a bumpy surface (like a rock or a piece of wood) and makes the 3D model look like it is bumpy too, even though the model itself is just one flat piece. Normal mapping can be used to make the 3D model look like it has different depths, ridges, and bumps, without actually adding those details in 3D.