This is great stuff, easy to follow along even for a dabbling novice like myself. I&#x27;ve always been interested in simulating light, and wrote a paper (and shader) in high school about simulating sub-surface light scattering effects. I remember when I had saved up enough money to buy H. W. Jensen&#x27;s book on photon mapping, and spending countless nights trying to decipher what it said. It&#x27;s actually a very good book, but the maths was way above my head in high school – still is, actually.<p>Any way, great work, and beautiful demo! I&#x27;ve spent more time playing with it now than I should have, and work is suffering for it. I regret nothing! :o)