mapping (aka normal mapping) is technique for simulating bumps and wrinkles on
the surface of an object.It
is achieved by perturbing the surface normal for each fragment being
rendered. The new normal is used in
per-fragment lighting calculations.
result is a surface that appears bumpy, even though the underlying position of
points on the surface is unchanged.Source:Paul's Projects
mapping can be implemented using multi-texturing. A texture representing the normal
displacement can be loaded.
are represented as RGB in the texture, in the tangent space of the surface.
rendering, the surface normals are displaced based on the texture. The displaced normal is used for calculating
the Cookbook for a recipe.