RT @Peter_shirley: I've decided to make pdf's of my ray tracing books available at "pay what you want". This can include zero, which I encourage for students and any other cash-strapped people. 50% of gross proceeds will go to programming education non-for-profits. https://t.co/RHZKjvseIT

I've decided to make pdf's of my ray tracing books available at "pay what you want". This can include zero, which I encourage for students and any other cash-strapped people. 50% of gross proceeds will go to programming education non-for-profits. https://t.co/RHZKjvseIT

— Peter Shirley (@Peter_shirley) April 14, 2018