Abstract: Aiming at the problem of achieving height from a normal map,this paper proposed an algorithm recovering height information from a normal map of surface normals which are defined as three-dimensional vectors．The algorithm starts from a plane storing surface normals to construct a plane storing height difference,then accumulate neighbor pixel height from a certain location in pixel lattice．After all pixel do the same calculation,it again proceeds to a certain location using already calculated heights．This iteration ends according to the accuracy needed, and the total accumulated height is averaged．The experiment result shows that this algorithm can generate a relative high resolution height map,and it can be used well in relief map which has a better bump effect.

Key words: Surface reconstruction,Height estimation,Surface normal,Polar coordinates summation