A company called Caustic Graphics built an FPGA ray tracing hardware accelerator once, called the CausticOne and CausticTwo: http://www.pcper.com/reviews/Graphi

A company called Caustic Graphics built an FPGA ray tracing hardware accelerator once, called the CausticOne and CausticTwo: http://www.pcper.com/reviews/Graphics-Cards/Caustic-Graphics-Ray-Tracing-Acceleration-Technology-Review/CausticOne-and-Ca http://www.pcper.com/reviews/Graphics-Cards/Caustic-Graphics... As I understood it back then (2010), it was a big step forward in performance. But the company was purchased by Imagination Technologies, and I haven't really heard about it since.