Bump mapping is a technique used in graphics programs to produce the appearance of textured surfaces. It works by altering the brightnesses of the pixel s in specific patterns. The result is similar to that produced when light shines at an angle on a surface.
By means of bump mapping, a sphere can be made to look like an orange. An apparently horizontal plane can be given the appearance of a pond with ripples, an asphalt parking lot, or a grassy lawn. Bump mapping is used in gaming programs to produce the illusion of relief. It is also used in such diverse applications as biology, chemistry, astrophysics, and architecture.
The most sophisticated form of bump mapping is called per-pixel lighting or Phong shading . Programs that perform this version of bump mapping are expensive, and they require considerable memory and processing power in order to run. Emboss bump mapping, a less sophisticated form, is easier to emulate on the chips commonly used with personal computers. Such effects also lend themselves to transmission over Internet connections for online gaming.