Normal Maps

Here's something cool that game artists do to make stuff look good. Pictured above is a normal - a line that shows the angle at which light rays bounce off a surface.

Bumpy surfaces have normals that kinda look like this.

In game art, we use normal maps to assign varied normals to otherwise flat surfaces.

Here's two models of the rocket launcher from Doom. Each pink dot is a vertex, a point of information that the game processes to define the model. As you can see, one is far more detailed than the other.

Through a process called baking, I can transfer normal data from the detailed model to the low-res model, in the form of the normal map pictured here.

This is how games can have really cool-looking models that don't fry your computer. Cool, right?