Traditionally, photos' lighting can only be manipulated by a photographer in a controlled studio, but a new AI algorithm can change shadows in an image AFTER it has already been taken. Although it's still running into issues with complex shadows and keeping images realistic, the foundation is very strong.
"Portrait Shadow Manipulation" by Xuaner (Cecilia) Zhang, Ren Ng:
https://people.eecs.berkeley.edu/~cecilia77/project-pages/portrait
subsurface scattering by J. Jimenez, K. Zsolnai, A. Jarabo, C. Freude, T. Auzinger, X-C. Wu, J. von der Pahlen, M. Wimmer and D. Gutierrez
https://users.cg.tuwien.ac.at/zsolnai/gfx/separable-subsurface-scattering-with-activision-blizzard/
