Bump mapping requires heavy processing resources and is usually hardware driven. Bump mapping calculation support is specified by 3-D graphics card chips. Bump mapping adds surface detail by responding to light direction.
Two popular bump mapping types are:
Emboss bump mapping: A multipass algorithm technique that extends texture embossing and duplicates texture images. The images are then shifted to the desired bump amount, underlying texture is darkened and excess texture is trimmed. Finally, the duplicate texture images are combined as one. Emboss bump mapping is also known as two-pass emboss bump mapping.
Environment mapped bump mapping (EMBM): A surface detailing method that incorporates texture/bump/environment maps. Bump and environment maps combine after the shifted environment map is applied to the texture map.