Normal mapping has a long history. Jim Blinn did the original work in 1978, with "Simulation of Wrinkled Surfaces" [0] which precomputes the normal pertubation

Normal mapping has a long history. Jim Blinn did the original work in 1978, with "Simulation of Wrinkled Surfaces" [0] which precomputes the normal pertubation into a height texture ("bumpmap") and does some sleight of hand arithmetic to integrate it back, and there was a ton of noise about putting it in hardware around 1998 or so. The modern normal map was introduced by Kilgard as a rotation on top of the unperturbed surface normal [1] in surface tangent space, allowing it to be encoded with three channels, and compressed to two. [0] https://www.microsoft.com/en-us/research/wp-content/uploads/1978/01/p286-blinn.pdf https://www.microsoft.com/en-us/research/wp-content/uploads/... [1] http://developer.download.nvidia.com/assets/gamedev/docs/GDC2K_gpu_bump.pdf http://developer.download.nvidia.com/assets/gamedev/docs/GDC...