Bump Map

A bump map is an image that stores a direction at each pixel. These directions are called normals. Bump maps are also called normal maps. The red, green, and blue channels of the image are used to control the direction of each pixel's normal.

Bump maps should be generated from high-poly geometry for the best consistency and surface detail. However, it is often necessary to create normal maps from source photography and textures. This can be done using https://github.com/kmkolasinski/AwesomeBump or Blender.