Ratatouille's Lighting and Shaders

[jeremybirn]

By the way, on bahalf of all the Pixar employees who read this forum, I apoligize for the fact that we don't post trade secrets or release information on our own about what happens at work. Maybe when the movie opens on June 29, you can go see it a few times, and all of the secrets will become apparent on the 10th or 11th viewing of the film. ;)

-jeremy

[CaptainObvious]

I don't really see what's so special about it. Don't get me wrong, Ratatouille looks absolutely stunning, and I can't wait to go see it, but I really don't see anything in that screen capture that looks like it requires some special secret technique. It's basically just skilled people working very hard, I'm guessing. It takes time to properly light a scene. You can't just slap on a pre-made light rig and have it look stunning. It takes time.

If you want to recreate an effect like that, I suggest that you break it down into the different components. First, look at the different light sources in the scene. Try to identify where the ratio between key lights and other lights, the usage of fill lights, bounce lights, rim lights, etc. Then look at how different materials react. In that image, you have plenty of good examples: the diffuse shirt and table cloth react in a completely different way frmo the fairly specular grapes and the shiny plates and knives and whatnot. I'm just guessing here, but the specular highlights on the glossy surfaces (like the grapes and the metal railing on the cart) is probably actual specular highlights from several lights, rather than ray traced reflections. Or a combination.

Also, for something that like, I'm willing to bet that they used either ambient occlusion, or global illumination, or both.

Another thing to keep in mind, is that Pixar doesn't seem to aim for photo-realism, as such. Rather, it seems to me that they're aiming for a more impressionistic look. So don't limit yourself to physical accuracy; if it looks good, do it!

As for getting things saturated, that's easy: just make things more saturated! ;)

[WolfMcfly]

They don't try to do things as the real world looks like, they do like we see the world.. it's hard to do, if you want something to be well done..

Pixar's movies are good not becouse they do things that looks pretty.. they have great historys, and their worlds are perfect for that historys..

Ratatouille for example.. tells a history of a rat who dreams about be a chef.. and all the food in that world looks so beautifful, and magic.. it's just not technical.. it's not just lighting a scene.. it's make a world where every thing, even the light, tells us something about the history.. everything is part of that history..

That is wath makes it special for me.. again, personal opinion.. ^^

[Matt]

Just looks like a lot of 'glow' post processing to me.

[CaptainObvious]

Just looks like a lot of 'glow' post processing to me.
That is one part of the equation, yes.

[eem]

Pixar uses that custom post-lighting system they developed in house. The lighting in that is probably the product of many directional lights added in post and then tuned on a per object basis to mimic all the various lighting effects. Like the grapes alone probably has it's own set of multiple lights all done in post, the cheese it's own set, the guys shirt another etc. On each one they probably place different rim lights in intensities, colors and whatnot to get a specific effect per shader. I bet the actual shaders they use aren't very complex, maybe even just lambert because I believe they can get specular highlights in their post lighting system. it's just that they can set up extremely complex and highly tuned lighting rigs so easily in post so they can get pecuilar looks like that. They do use ambient occlusion in the system though.

[jeremybirn]

Pixar uses that custom post-lighting system they developed in house. The lighting in that is probably the product of many directional lights added in post and then tuned on a per object basis to mimic all the various lighting effects. Like the grapes alone probably has it's own set of multiple lights all done in post, the cheese it's own set, the guys shirt another etc. On each one they probably place different rim lights in intensities, colors and whatnot to get a specific effect per shader. I bet the actual shaders they use aren't very complex, maybe even just lambert because I believe they can get specular highlights in their post lighting system. it's just that they can set up extremely complex and highly tuned lighting rigs so easily in post so they can get pecuilar looks like that. They do use ambient occlusion in the system though.

That was the best post EVER! :thumbsup:

I have even forwarded it to some of those lambert-writin' shader TDs! ;)

If anyone else wants to post some brilliantly creative fan-fiction, feel free to join in!

-jeremy

[WolfMcfly]

I knew that are some ways to do glossy with post-processing..

But i didn't knew that lambert had such power.. hehe..

[CaptainObvious]

It's a well-kept secret, but Pixar's films aren't actually lit in 3D. They just render out a basic texture pass, along with a normal pass. Then they use the normal pass as a reference for, by hand, painting light into the scene. It's really cool. :thumbsup: I think they use Photoshop, but I'm not sure. It could be Paint.NET as well.

[soulburn3d]

Wow, this is quite a thread.

- Neil
Pixar Animation Studios
Lambert Application Engineer

[TheNeverman]

lol, and we haven't even started talking about Mr. Jobs yet...
:)

really though, can we expect so see an iPod or iPhone make an appearance on the Pixar big-screen anytime soon?
:)


Wow, this is quite a thread.

- Neil
Pixar Animation Studios
Lambert Application Engineer

[tilomit]

That was the best post EVER! :thumbsup:

I have even forwarded it to some of those lambert-writin' shader TDs! ;)

If anyone else wants to post some brilliantly creative fan-fiction, feel free to join in!

-jeremy

I'm laughing my ass off LOL

[lgslgs]

I heard that all of the lighting was done by that chef rat's artsy cousin. and that they're already working on the sequel movie featuring Cousin Lamberto.


Lynda

[WolfMcfly]

so... let's do a "Lambert Challenge"?? :)

[eem]

That was the best post EVER! :thumbsup:

I have even forwarded it to some of those lambert-writin' shader TDs! ;)

If anyone else wants to post some brilliantly creative fan-fiction, feel free to join in!

-jeremy

:D I guess I'll take this as a compliment to my ability to make stuff up that sounds like it's correct.

But hey guys... it's plausible, fiddle around with the deep shader node in fusion 5.1, you can replicate all sorts of shader effects in post with just a lambert shadowed render and a normal pass, get a bent normal pass in there and theres even more possibilities. I was imagining thats sort of how lpics worked and what it was used for.

[psv]

:D I guess I'll take this as a compliment to my ability to make stuff up that sounds like it's correct.

But hey guys... it's plausible, fiddle around with the deep shader node in fusion 5.1, you can replicate all sorts of shader effects in post with just a lambert shadowed render and a normal pass, get a bent normal pass in there and theres even more possibilities. I was imagining thats sort of how lpics worked and what it was used for.

dont be sad ...........i believe you!

[playmesumch00ns]

I dont'!

......

[psv]

I dont'!

......
then maybe you should relese some ``real`` trade secrets:thumbsup:...1st of April it`s such a handy feature....:)

[jeremybirn]

then maybe you should relese some ``real`` trade secrets:thumbsup:...1st of April it`s such a handy feature....:)

That's the funny thing: Pixar has released lots and lots of real trade secrets. It's through a controlled process, not each employee winging it on Internet forums, but Pixar is one of the companies that's a leading source of the SIGGRAPH papers and courses. For example, if you cared about what LPICS really was, instead of listening to someone pull stuff out of his air, you could read the paper as a PDF and even watch a short video here:

http://www.vidimce.org/publications/lpics/

-jeremy

[psv]

That's the funny thing: Pixar has released lots and lots of real trade secrets. It's through a controlled process, not each employee winging it on Internet forums, but Pixar is one of the companies that's a leading source of the SIGGRAPH papers and courses. For example, if you cared about what LPICS really was, instead of listening to someone pull stuff out of his air, you could read the paper as a PDF and even watch a short video here:

http://www.vidimce.org/publications/lpics/

-jeremy

sure ..., you are right Jeremy , it was a joke :).....

[playmesumch00ns]

That's the funny thing: Pixar has released lots and lots of real trade secrets. It's through a controlled process, not each employee winging it on Internet forums, but Pixar is one of the companies that's a leading source of the SIGGRAPH papers and courses. For example, if you cared about what LPICS really was, instead of listening to someone pull stuff out of his air, you could read the paper as a PDF and even watch a short video here:

http://www.vidimce.org/publications/lpics/

-jeremy

Absolutely. The graphics.pixar.com research page is packed full of interesting stuff to read.

Incidentally Jeremy, how extensively was LPICS actually used and is it still being used? In Fabio Pellacini's Siggraph presentation last year he basically said that GPU relighting was a dead-end because you'd have to rewrite the software for every new show you did.

I don't know if I agree with that assessment, but it'd be interesting to know what brought him to that opinion.

Back on the 2.5D relighting stuff: basically you can't light in 2D, because it's 2D. Which means no shadows. And no shadows means bad lighting.

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