Bumps are applied by matching up a series of grayscale pixels with colored pixels on the rendered, colored object. Lighter grayscale pixels create a sense of maximum relief or maximum indentation; darker pixels have less effect.

A computer must contain a supporting 3D graphics card when it runs an application that has been coded to include bump maps. If the graphics card does not support bump mapping, then the bumps won't be seen. In the case of computer games, the programmer usually will code an alternate version that doesn't use bump maps. This version will look flatter and less real.

Bumpy 
This slick applet uses a "bump map" to create the effect of a spotlight passing over an image. Put your own unique logo in the spotlight!

Bump Mapping
Gives a description of bump mapping and pays close attention to the different types of bump-mapping calculations.

HardwareCentral: Video Cards
Read all about different video cards and find ones that support bump mapping.