01 When to use A bump MAP

At its simplest bump mapping only modifies the surface of a piece of geometry, whereas displacement mapping is actually altering the geometry. Bump maps are great at adding a lot of low-relief detail on low-polygon objects, so a one-polygon wall could show hundreds of bricks thanks to bump mapping.

It can be an issue when edge detail needs to be shown, as bump mapping does not work with side detail – it only shows the true underlying geometry.