It sounds like "Dual Photography". https://dl.acm.org/doi/10.1145/1186822.1073257 https://dl.acm.org/doi/10.1145/1186822.1073257 "We present a novel photograp

It sounds like "Dual Photography". https://dl.acm.org/doi/10.1145/1186822.1073257 https://dl.acm.org/doi/10.1145/1186822.1073257 "We present a novel photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. With a video projector providing structured illumination, reciprocity permits us to generate pictures from the viewpoint of the projector, even though no camera was present at that location." I recommend watchign the video from the paper for good explains and demonstrates the technique. It's very impressive work. https://www.youtube.com/watch?v=p5_tpq5ejFQ https://www.youtube.com/watch?v=p5_tpq5ejFQ