Going through the patents from the author[1] is probably the best technical resource about their secret sauce. In particular US9684946B2[2] seems to be the foun

Going through the patents from the author[1] is probably the best technical resource about their secret sauce. In particular US9684946B2[2] seems to be the foundational patent about the tech. As others mentioned already, Vedutismo/Pannini projections seem closely related here, but they might be doing some extra on top of that. [1] https://patents.google.com/?inventor=Robert+Christian+PEPPERELL https://patents.google.com/?inventor=Robert+Christian+PEPPER... [2] https://patents.google.com/patent/US9684946B2/en https://patents.google.com/patent/US9684946B2/en