Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Pixar in a Box – Khan Academy

pixarinabox.org

Post reply on HN
Print view View original

21–30 of 69 posts

Re: Pixar in a Box – Khan Academy

#21

Post by Keyframe »

britcruise wrote: post #2

Hey HN! My name is Brit Cruise and I'm the lead content developer on the Khan Academy side of this equation (working alongside Tony DeRose from Pixar...plus a village of others), if you have any specific questions about this project I'll be happy to answer as best I can.

There is an undergrad (I think it's an undergrad) course on Ray Tracing for Global Illumination here https://www.youtube.com/playlist?list=PLslgisHe5tBPckSYyKoU3...

I've written an RSL tutorial that has been online for past 15 years (it's currently offline, I'll put it up again) and I've had people from all over the world from different studios (big and small) thank me.. it seems RSL doesn't have much resources online and considering this is tied to Pixar - do you have plans for RSL?

Re: Pixar in a Box – Khan Academy

#24

Post by tomvbussel »

Keyframe wrote: post #21
britcruise wrote: post #2

Hey HN! My name is Brit Cruise and I'm the lead content developer on the Khan Academy side of this equation (working alongside Tony DeRose from Pixar...plus a village of others), if you have any specific questions about this project I'll be happy to answer as best I can.

There is an undergrad (I think it's an undergrad) course on Ray Tracing for Global Illumination here https://www.youtube.com/playlist?list=PLslgisHe5tBPckSYyKoU3... I've written an RSL tutorial that has been online for past 15 years (it's currently offline, I'll put it up again) and I've had people from all over the world from different studios (big and small) thank me.. it seems RSL doesn't have much resources onlin…

The CG by UC Berkeley on EdX is a great starting point. One of the exercises involves building a simple ray tracer. A slightly more advanced source on ray tracing is http://www.scratchapixel.com/. Of course the best way to learn about ray tracing is by reading Physically Based Rendering: From Theory to Implementation by Pharr and Humphreys.

Pixar has ditched RSL in favor of BSDFs written in C++, so there is no real reason for learning RSL anymore. Open Shading Language (OSL) is a new shading language which is getting more and more use in the industry, but it's completely different by design.

Re: Pixar in a Box – Khan Academy

#25

Post by andymatuschak »

thespace123 wrote: post #17
britcruise wrote: post #2

Hey HN! My name is Brit Cruise and I'm the lead content developer on the Khan Academy side of this equation (working alongside Tony DeRose from Pixar...plus a village of others), if you have any specific questions about this project I'll be happy to answer as best I can.

Are you going to add this content to your iOS app? Also my friend is looking forward to that Android app!!

The non-interactive content should mostly work in the iPad app. iPhone is trickier.

This is a tough area for us in general, unfortunately.

Re: Pixar in a Box – Khan Academy

#26

Post by sitkack »

ska wrote: post #10
ginko wrote: post #8

It's interesting that the Rendering chapter only covers ray tracing, while most classic Pixar movies were actually mainly rendered using the Reyes algorithm, which is a form of rasterization.

Isn't Reyes essentially a speed hack [1]? As so, is it particularly relevant to learn about today in introductory material? [1] by which i mean, inferior estimation of BSDF on/in model, but much much faster.

I think it is important to know what the trade offs are in terms of speed, cost, quality. Lots of children's TV programs look like they are rendered with Unity or worse. Most likely on a single machine in real time.

Re: Pixar in a Box – Khan Academy

#27

Post by ska »

tomvbussel wrote: post #19
ska wrote: post #10

Earlier quoted context omitted.

Isn't Reyes essentially a speed hack [1]? As so, is it particularly relevant to learn about today in introductory material? [1] by which i mean, inferior estimation of BSDF on/in model, but much much faster.

The REYES algorithm is an algorithm that can very quickly produce batches of shading points (with the required information to shade them such as the viewing direction). It's not really a hack and you can still use path tracing (with BSDFs) to correctly shade these points. In fact this is what Pixar did for Monster's University; they used the REYES algorithm to determine shading points visible from the camera and then…

Isn't that complimentary to what I said though? You could presumably get the same result by just path tracing the whole thing, so all you've gained is speed at the cost memory. I didn't mean speed hack in a pejorative way.

I understand why you might want to do this in practice, but it still doesn't seem to be that important to teach as an introduction.

Re: Pixar in a Box – Khan Academy

#28

Post by tomvbussel »

ska wrote: post #27
tomvbussel wrote: post #19

Earlier quoted context omitted.

The REYES algorithm is an algorithm that can very quickly produce batches of shading points (with the required information to shade them such as the viewing direction). It's not really a hack and you can still use path tracing (with BSDFs) to correctly shade these points. In fact this is what Pixar did for Monster's University; they used the REYES algorithm to determine shading points visible from the camera and then…

Isn't that complimentary to what I said though? You could presumably get the same result by just path tracing the whole thing, so all you've gained is speed at the cost memory. I didn't mean speed hack in a pejorative way. I understand why you might want to do this in practice, but it still doesn't seem to be that important to teach as an introduction.

I guess I didn't fully understand your post then, I thought you meant that the Reyes algorithm is an "inferior estimation" and that it might be beneficial to add it to a renderer, but neither is the case. But it isn't an inferior estimation (just a different way of computing things) and you don't want to use the Reyes algorithm in practice as scenes either barely fit in memory or they don't fit in memory at all (and in that case you want your memory usage to be as efficient as possible to avoid reading from the disk as much as possible).

Re: Pixar in a Box – Khan Academy

#29

Post by Keyframe »

tomvbussel wrote: post #24
Keyframe wrote: post #21

Earlier quoted context omitted.

There is an undergrad (I think it's an undergrad) course on Ray Tracing for Global Illumination here https://www.youtube.com/playlist?list=PLslgisHe5tBPckSYyKoU3... I've written an RSL tutorial that has been online for past 15 years (it's currently offline, I'll put it up again) and I've had people from all over the world from different studios (big and small) thank me.. it seems RSL doesn't have much resources onlin…

The CG by UC Berkeley on EdX is a great starting point. One of the exercises involves building a simple ray tracer. A slightly more advanced source on ray tracing is http://www.scratchapixel.com/ . Of course the best way to learn about ray tracing is by reading Physically Based Rendering: From Theory to Implementation by Pharr and Humphreys. Pixar has ditched RSL in favor of BSDFs written in C++, so there is no real…

Yes, you're right about RSL. What I've meant is that it is (was) a good learning tool. Maybe something like shadertoy today with an appropriate course would be apt?

PBRT is a great resource too. I don't know if they opted out of literate programming? I can't stand that for some reason. I've leafed through PBRT though. I've learned (back in the day, hah) from Shirley's Ray Tracing book and bibles that Andrew Glassner wrote (Principles of Digital Image Synthesis) which I still consider awesome resource.

Re: Pixar in a Box – Khan Academy

#30

Post by pamelafox »

ChicagoBoy11 wrote: post #14

Wonderful initiative -- wish this was around when I was in school. Any projects in the works to tie this into Khan Academy's CS offerings? I work at a school which is about to pilot a programming class with 3d animation, but I found the content which you guys have put up to be far more engaging. If there were an accompanying suite where students could code and render an entire scene (especially if some Pixar assets w…

I'm Pamela, the programming teacher for KA. We're thinking about adding highly guided coding challenges to the PIAB content in the future, to entice students to go deeper into programming. Alternately, we could add advanced coding challenges that have a higher prereq. We haven't quite figured out the approach yet (and that applies generally to introducing programming to other areas of KA). Feel free to email compsci-feedback@khanacademy.org with your thoughts. :)
Post reply on HN