At least there's a simple equation [0] for the deflection of light rays caused by a black hole. If your background is a UV map (for example), then it should be

At least there's a simple equation [0] for the deflection of light rays caused by a black hole. If your background is a UV map (for example), then it should be easy to compute the distortion effect. rantonels (whose raytracer was the source of inspiration for mine) has done a realtime version [1] -- I believe this should be close to what you're talking about. [0] https://en.wikipedia.org/wiki/Gravitational_lens#Explanation_in_terms_of_space.E2.80.93time_curvature https://en.wikipedia.org/wiki/Gravitational_lens#Explanation... [1] http://spiro.fisica.unipd.it/~antonell/schwarzschild/ http://spiro.fisica.unipd.it/~antonell/schwarzschild/