J Turner Whitted explains how he stumbled into global illumination

NVIDIA has published an article by J Turner Whitted, one of the pioneers of raytracing, explaining the background to his 1979 paper  An Improved Illumination Model for Shaded Display that was an important contribution to today’s ray-traced computer graphics techniques. One entertaining titbit in the article was the fact that the technique of adaptive super-sampling (adding samples only where they are needed) came about to reduce render times in an effort to meet a SIGGRAPH submission deadline, proving once again that old proverb that necessity is the mother of invention. According to Whitted, the technique “was implemented within a couple of hours and the paper was edited to include this new idea while the illustrations were being rendered”. Read the article in full on the NVIDIA’s blog.