|Microsoft DirectX 9.0|
A bump map is an IDirect3DTexture9 object that uses a specialized pixel format. Rather than storing red, green, and blue color components, each pixel in a bump map stores the delta values for u and v (DU and DV) and sometimes a luminance component, L. These values are applied by the system as described in the Bump Mapping Formulas topic.
You can specify a bump map pixel format by setting the format to one of the following: D3DFMT_CxV8U8, D3DFMT_V8U8, D3DFMT_L6V5U5, D3DFMT_X8L8V8U8, D3DFMT_Q8W8V8U8, or D3DFMT_V16U16. For descriptions, see D3DFORMAT.
The DU and DV components of a pixel are signed values that range from ?.0 to +1.0. The luminance component, when used, is an unsigned integer value that ranges from 0 to 255.