Billions and Billions of Path Traces

October 17, 2013 4:11 AM

The Physics of Light and Rendering is a talk given at QuakeCon 2013 by John Carmack, co-creator of Doom, Quake, and many other games at id Software and beyond. It provides a detailed but surprisingly understandable history of 3D rendering techniques, their advantages and tradeoffs, and how they have been used in games and movies. (SLYT, 1:32:01, via)
posted by cthuljew (9 comments total)

I've always found Carmack's quakecon presentations enjoyable. He doesn't have the showmanship of many keynote speakers, but he talks in such flowing and informed way that they're utterly compelling. Mesmerizing even.

Now if you'll excuse me ... I feel compelled to go and write a Monte Carlo method path tracer ...
posted by samworm at 4:47 AM on October 17, 2013 [1 favorite]

For a relatively technical presentation it's interesting that he uses the phrase "bounces off" to describe reflection without (as far as I could tell) explaining that that's just an informal short-hand. In reality, photons are absorbed and emitted. They don't actually bounce off of things like little ping-pong balls.
posted by jedicus at 8:15 AM on October 17, 2013

Utterly fascinating, thanks for sharing this!

Also: cargo shorts.
posted by ericbop at 10:07 AM on October 17, 2013

wow. this was quite interesting. I got about 10% of it, but I enjoyed it all.
posted by rebent at 10:12 AM on October 17, 2013

Well, they are trying to get Newton down before they get to Planck, so I'm not surprised that he's eliding over quantum mechanics.
posted by empath at 10:12 AM on October 17, 2013

I am super excited to sit down and watch this when I have some time next week.
posted by Theta States at 10:20 AM on October 17, 2013

empath: Well, they are trying to get Newton down before they get to Planck, so I'm not surprised that he's eliding over quantum mechanics.

There's going to come a day when, instead of polygon count, our video cards will advertise how many photons they can simulate at once; the upside is our video games will get realistic windows and mirrors!

Then, a few years later, how many p-branes they can simulate, and then the singularity will be upon us.
posted by AzraelBrown at 2:16 PM on October 17, 2013

jedicus, the treatment of light propagation in computer graphics is almost entirely geometric, although there are exceptions. If you're rendering everyday scenes, it turns out it's mostly fine to treat light as a collection of rays that bounce around (with various degrees of complexity in the bouncing).
posted by Serf at 2:19 PM on October 17, 2013 [1 favorite]

I love his talks, but do I ever wish there were a transcript.
posted by kandinski at 2:39 PM on October 17, 2013 [1 favorite]