R. Keith Morley Solomon Boulos Jared Johnson David Edwards Peter Shirley Michael Ashikhmin Simon Premoze Image synthesis using adjoint photons. 179-186 2006 conf/graphicsinterface/2006 Graphics Interface http://doi.acm.org/10.1145/1143079.1143109 db/conf/graphicsinterface/graphicsinterface2006.html#MorleyBJESAP06