Efficient bump mapping hardware

We present a bumpmappingmethod that requires minimal hardware beyond that necessary for Phong shading. We eliminate the costly per-pixel steps of reconstructing a tangent space and perturbing the interpolated normal vector by a) interpolating vectors that havebeen transformed into tangent space at polygon vertices and b) storing a precomputed, perturbed normal map as a texture. This represents a considerable savings in hardware or rendering speed compared to a straightforward implementation of bump mapping. CR categories and subject descriptors: I.3.3 [Computer Graphics]: Picture/Image generation