Bump mapping

Have you ever run your hand over something that had bumps on it, like a Lego block or the sole of a shoe? Bump mapping is a way to make things in video games and computer graphics look like they have bumps too.

It works by adding a special type of texture to the surface of the object. This texture is a map of all the bumps and dents that are supposed to be on the surface. When the object is rendered, the computer uses this map to change the way light reflects off the surface.

If a bump is supposed to be there, the computer makes that part of the surface look like it's sticking out a little bit. If there's supposed to be a dent or a scratch, the computer makes that area look like it's been pushed in.

Bump mapping is a clever way to make objects look more realistic without actually adding more geometry to the model. It's like putting a sticker on the object that says "bumpy" or "scratchy" so the computer knows how to make it look.