Texture maps

Colour Maps

You can also use colour maps as a starting point for many other texture types, like bump or specular, because the colour often changes in the same areas as other aspects of the material change.

Bump Maps

 A bump map is a grayscale image that acts as a pseudo-height map. It doesn’t actually create any extra geometry, all a bump map does is create the illusion of raised or lowered details on the surface of your model.

Normal Maps

Instead of a grayscale image like a bump map, a normal map is basically a map of what direction your geometry’s normals are facing. With this information, the illusion of anything from height to how your model is affected by lighting can be faked.

Specular Maps

a wet piece of plastic will reflect light completely differently than a dry piece of plastic. The color may be the same and it may have the same amount of bumpiness, but you can control how shiny it is with a specular map. For a basic specular map, you can use dark tones to reduce the specularity and lighter tones to create a stronger highlight.