Try doing a stochastic spread of the rays sent through each pixel, with attenuation based upon differences in the surfaces reached by the rays. I was able to cr

Try doing a stochastic spread of the rays sent through each pixel, with attenuation based upon differences in the surfaces reached by the rays. I was able to create an adaptive raytracer with 4 test rays per pixel and up to 56 when adaptively needed. The speed gain is quite significant, with visual clarity equal to simpler renders requiring much more time.