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Pixar's Chris Horne Sheds New Light on Monsters University
- newgre 13y agoAn article about a new dimension in rendering quality, and they're demonstrating that quality with two images the size of a stamp...WAT?
- uptown 13y agoLarger versions: http://bluraymedia.ign.com/bluray/image/article/104/1044870/monsters-inc-20091112044224899-000.jpg http://bluraymedia.ign.com/bluray/image/article/104/1044870/... http://pixartimes.com/wp-content/uploads/2012/08/Monsters-University-Research-1.png http://pixartimes.com/wp-content/uploads/2012/08/Monsters-Un...
- sp332 13y agoSince the movie isn't actually out, this is more of a promotional piece. Also the first image is a bit bigger http://pixartimes.com/wp-content/uploads/2012/08/Monsters-University-Research-1.png http://pixartimes.com/wp-content/uploads/2012/08/Monsters-Un... but is fairly low-quality and for some reason is scaled down to stamp-size on the page.
- aidenn0 13y agoComparing raster graphics from 12 years ago to ray-traced graphics from today isn't a fair anyway. Part of why raster has persisted against ray-tracing for so long (despite numerous predictions to the contrary) is that raster graphics techniques are constantly improving.
- gfodor 13y agoWow, I had always assumed Pixar was doing GI/ray tracing by now. Looking forward to seeing MU to check out the graphics porn.
- KaiserPro 13y agoIronically Renderman has had global illumination and ray tracing for over ten years. Having said that, what renderman is and what pixar animation do/use are rather orthogonal. For example pixar made heavy use of Subsurface scattering in the incredibles. Something that was at the time rather time intensive. The title is a bit misleading as they've been using raytracing for years 1 [1]http://graphics.pixar.com/library/RayTracingCars/paper.pdf http://graphics.pixar.com/library/RayTracingCars/paper.pdf
- bendavis381 13y agoThey were doing GI before, but using an approximate point-based solution. The point-based stuff isn't as accurate but it's very fast and still looks pretty good.
- mtgx 13y agoFrom what I gathered from John Carmack, ray tracing is done much more efficiently with voxels than with triangles, so hopefully this will push game engine companies to incorporate voxels sooner into their engines, too.
- dmauro 13y agoThey're already on it. The Unreal 4 engine will use voxel cone tracing: http://www.unrealengine.com/files/misc/The_Technology_Behind_the_Elemental_Demo_16x9_(2).pdf http://www.unrealengine.com/files/misc/The_Technology_Behind...
- dualogy 13y agoAn invisible voxelized-representation of polygonal scene geometry is used there for approximating global illumination of visibly rendered polygonal geometry. Hence, it's not a realtime "voxel engine" as far as visual rendering goes.
- Guvante 13y agoUnfortunately pre-rendering and real-time rendering are worlds apart. Pixar probably didn't need to do a voxel -> triangle transformation to their data set if they were using voxels, but any real-time renderer does.
- angersock 13y ago"Let's add voxels!!!111one" is one of the most irritating refrains of gamers. There are a lot of very nice mathematical properties of triangles, and the trend towards graphical fidelity has really only served to balloon budgets in the gaming space. We don't need voxels, and honestly neither do we need ray tracing. It's not even new tech--games going back to Outcast, some Build engine games, Novalogic stuff, and so on have used voxels. Ray tracing has been used in a handful of nifty tech demos, but otherwise nobody cares. Ray tracing and voxel tech is of marginal utility for games, and things have moved on--it'd be like switching the US construction industry over to metric; too late to make a difference and too minor to matter. EDIT: In spite of all this, voxel cone tracing looks sexy as hell though.
- aaronbrethorst 13y agoI was surprised that ray tracing in Pixar was historically a clunky, haphazard process. I always thought of it as this smooth, polished machine like something you would see at an Apple store. Life inside the sausage factory never quite looks like what outsiders would expect.
- angersock 13y agoEven if it renders everything you ever saw.
- danielweber 13y agoI think it's awesome how they thought something was too hard, and so they faked it to be "good enough." I'm going to have to look more critically at Pixar movies now, knowing that the old ones didn't have actual calculated light sources.
- joshuak 13y agoActually light sources have always been the only thing 'traced'. We used to use them to trick ray tracing in the early days of RenderMan (put an image in the lightsource so you can 'reflect' it). It's surface to surface and other GI effects that where late to the party. Nevertheless we often faked that with massive light counts. For the opening shot of Armageddon with the astroid hitting earth I used 20,000 point lights to represent secondary debris reentering the atmosphere. In 1998 or when ever that was it still only took RenderMan a few minutes to render each frame.
- zrail 13y agoOT: (fanboi alert) I think it's really cool that you're posting here. Pixar is one of those places that I think would be really really cool to work for but that I don't have the skillset for. For the record, I have an original print of the RenderMan book that I read cover-to-cover when I was a kid.
- deleted 13y ago[deleted]
- 38leinad 13y agoAnybody knows how other companies like universal's animation department (ice age, despicable me, ...) stand technology-wise? From the visuals, i always assumed pixar is setting the standards but now knowing that they just start to use unified raytracing, the gap might not be that big...
- ohazi 13y agoIce Age / Rio / Epic are Blue Sky, not Universal.
- dietrichepp 13y agoAt least historically, Pixar wasn't just a studio but also sold their renderer to others as software. http://en.wikipedia.org/wiki/RenderMan http://en.wikipedia.org/wiki/RenderMan
- joezydeco 13y agoAt least super-historically, Pixar wasn't just a software company but a hardware company as well: http://en.wikipedia.org/wiki/Pixar_Image_Computer http://en.wikipedia.org/wiki/Pixar_Image_Computer
- Ricapar 13y agoWhy does it matter that much what technology is in the backend? You lead the industry with results, not with the means to get to those results. If I can make my webapp better (however you define "better") than my competitors' using PHP and MySQL, while they're making theirs using Ruby on Rails, MongoDB, etc,etc. Does the tech stack in the background matter, aside from making a nice article?
- outworlder 13y agoSorry, but the comparison is incredibly flawed. Your PHP or Rails code will still generate HTML in the end.
- jacquesm 13y ago
- glut 13y agoWhat sort of raytracing are they using? Are they going all the way to an unbiased global light transport algorithm (like LuxRender) or just using basic raytracing (like PovRay)? Are they using an existing renderer? If not, are they releasing their own like they did with RenderMan? Are they rendering with CPUs or with GPUs? How much time per frame does it take them with how many cores of what sort?
- joshuak 13y agoInteresting questions. I don't have the answers, but I can say that I can't imagine that Pixar would ever 'go all the way' to an 'unbiased' GI renderer. Our entire function in the filmmaking business is to tell a story visually, and for that you need complete control and directability of the image. This is the opposite goal of unbiased renderers. Nevertheless more tools in the tool box is always good.
- berkut 13y agoUnbiased actually isn't slow - Arnold has proved this - what's slow is using hundreds of bounces per path and bi-directional path tracing (like Maxwell, Indigo, LuxRender) which takes a lot longer. Biased generally means it's interpolated with a point or irradiance cache.
- KaiserPro 13y ago1) http://renderman.pixar.com/view/raytracing-fundamentals http://renderman.pixar.com/view/raytracing-fundamentals 2) Unbiased renderers like Maxwell and arnold very different beasts. Unbiased renderes have only become practical with moore's law. Renderman is so prevalent because its both fast and flexible. Maxwell specifically has a very distinct look. 3) its renderman. They eat their own dog food. 4) CPU, with GPU bits for specialist stuff 5) AAAAAAGGGEESS 24hours a frame in some cases. even more if there is lots of fur/water
- berkut 13y agoThey're using uni-directional path tracing - if they're using PRMan 17 (Which I think they were), it'll probably be unbiased like with Arnold. So it's unbiased, but unidirectional, unlike LuxRender's MLT (two-way path tracing). PRMan 17's a fairly good raytracer now (Arnold was giving PRMan a bit of a kicking in this department over the last two years). All on the CPU - there's no way GPUs can cope with the size of textures and geometry feature films need to cope with (up to 200 GB of textures and Geometry in some of the complicated scenes) - there's no way that's fitting on a GPU. I don't know what Pixar have, but SPI (who use their own version of Arnold) used to have quad socket i7s, so 64-thread machines with 96 GB of RAM two years ago - some of the more complex frames were taking +30 hours at 2k.
- joshuak 13y agoActually there's some incorrect information here, Pixar started using ray tracing in films as far back as A Bug's Life. I can't find a picture on line but you can see it in the scene with the glass bottle. That was done by integration with a separate render but since then RenderMan as added support for GI and other ray tracing features. I'm sure this update is significant, and sounds like a ground up reworking of the engine, perhaps replacing REYES? But it's not at all accurate to say the Pixar is moving to raytracing. Pixar has been in that neighborhood for more then a decade.
- gdubs 13y agoYep. A "Ray Server" technique where PRMan farmed out calls trace() calls to BMRT was used in "A Bug's Life" for the glass bottles at the grasshopper's hideout. All other reflection and refraction were done using 'standard-issue' environment maps. Source: Apodaca,Gritz, Advanced Renderman -- MK 2000.
- jarrett 13y agoFor a bit of background: The article talks a lot about global illumination. Here's what that means. First, you have to understand the cheaper alternative, which is called local illumination. With local illumination, for each pixel, you figure out what object you're looking at, and where on that object. You take into account the normal (direction of the surface at that point) and the optical properties of the object at that point. You also take into account the position, intensity, color, etc. of any light sources in the scene. Optionally, you may also take into account any shadow casting. That's it. What's missing from that list? It's a big one: You're not taking into account the way other objects in the scene affect that little point. In the real world, light bounces all around. Each little point is affected by pretty much each other little point. All the points are interdependent. But with local illumination, you ignore the way other surfaces contribute to the point's illumination. You're just looking at that one point and the light sources. That's why it's called local. Global illumination, by contrast, does take into account the interplay between different points in the scene. Its main purpose is to simulate light bouncing between polygons. As you can imagine, managing the complexity of all those interactions is a tall order. We have quite a few algorithms for this; all are approximations. It's worth noting that some of these approximations can converge towards a provably physically correct result if you let them run long enough. In any case, running global illumination often causes a major increase in rendering time. So it's understandable that Pixar, which has to render a huge number of frames at huge resolutions, did not traditionally use it much.
- swdunlop 13y agoThat is the most clear description I've ever seen of local vs global illumination. Thank you.
- grecy 13y ago> So it's understandable that Pixar, which has to render a huge number of frames at huge resolutions, did not traditionally use it much. Do we have any ball-park estimate of how long it takes Pixar to render a single frame of a movie like Monsters U? EDIT: Many people are mentioning it's done massively parallel, which I meant to include in my question. So, what I mean is, how long does it take to render a whole Pixar movie?
- masklinn 13y ago> ray tracing is a relatively advanced CG lighting technique Not really correct. Ray tracing is more like the most simple GC lightning technique you could imagine, but so incredibly computationally expensive people have been mostly waiting for the hardware to be good enough for the last 50 years. And in the meantime, they've been using an incredible pile of hack and tricks to try and approach levels of visual quality and complexity trivial on a raytracer, except said pile of hack could actually be computed before the heat death of the universe.
- berkut 13y agoThis is wrong actually - they've been using ray tracing for ages (all ambient occlusion in PRMan is done with raytracing, by sending out occlusion rays in a hemisphere around the shading point). What's new with MU is they're using both physically-plausible shading (where the shading is based off physically-based BRDF lighting algorithms, which gives much more realistic results), and global illumination path-tracing for the entire light transfer equation.
- ubercow13 13y agoThey explain the extent to which they used to use raytracing in the article - is it misrepresented? It's in a direct quote so I doubt it.
- berkut 13y agoYes, because the article (and the person in it) doesn't seem to understand the difference between path tracing (ray tracing with global illumination - multiple bounces even with diffuse surfaces), and ray tracing = sending rays around a scene and bouncing them off specular reflective/refractive surfaces - which Pixar have been doing for years. It's been possible to write raytraced shaders in PRMan for over 12 years now.
- splt 13y agoCars was in production about 10-12 years ago. Maybe you're thinking Cars 2?
- Tloewald 13y agoThe reflections on Buzz's helmet in Toy Story (the original) looked raytraced to me, although it might have been very well faked. I usec renderman in the mid 90s and it allowed selective raytracing per shader. Certaingly the guts at cgsociety think there was raytracing in both Toy Story and A Bug's Life. http://forums.cgsociety.org/archive/index.php/t-60329.html http://forums.cgsociety.org/archive/index.php/t-60329.html
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- ChuckMcM 13y agoI would love them to re-generate Brave with ray tracing, I'm guessing though that would take too many resources even for a blue-ray edition.
- cscheid 13y agoI think the worst part is the amount of man-hours it would take, not compute hours (but maybe that's what you meant?). If the change is as deep as it sounds like, the entire tooling support changed, so all scenes would have to be re-lit by artists, not-entirely-from-scratch but worse than you think. REYES-rendered scenes that fake global illumination are pretty arcanely hacked together. Just making a legacy scene ray-traced would make it look worse, not better.
- ChuckMcM 13y agoAbsolutely, which is why it won't happen. You'd have to actually place lights, remove the fakes, and render check every scene. Basically the only part of the movie you wouldn't have to do is come up with dialog, sound, and geometry. (not to mention I have never met a movie person who, given a chance to reshoot a scene says "Yeah, it was perfect when I shot it, the only changes here are mechanical." :-)
- asperous 13y agoNow that Pixar is only ray tracing, can real time move to scanline? I'd really like to see a lot more smooth shapes and complicated geometry in games if possible.
- wtracy 13y agoThat's pretty much what games already use. The only difference is polygon count--doubling the polygons tends to halve the framerate. That said, of the magic comes from a toolchain that lets artists work with curved surfaces (NURBS or similar) and that converts those surfaces to polygons at the last minute. We finally started getting hardware support for that sort of thing with DirectX 11 and OpenGL 4.
- RivieraKid 13y agoBtw, there's a pretty impressive real-time ray tracer in development: http://raytracey.blogspot.cz/ http://raytracey.blogspot.cz/
- mratzloff 13y agoI was wondering what Toy Story would look like if they re-rendered it with today's technology. Well, it turns out they already did! It was part of the theatrical re-releases of Toy Story and Toy Story 2 in 3D. http://www.bigscreenanimation.com/2008/09/toy-story-re-releases-being-re-rendered.html http://www.bigscreenanimation.com/2008/09/toy-story-re-relea... Were these re-rendered versions released in 2D on Blu-ray?
- baby 13y agoI wonder if you really see a difference.
- mackwic 13y agoYou won't see it but for sure you will perceive it ! ;)
- devindotcom 13y agoWell put!
- Cthulhu_ 13y agoWell, unless they changed the sources (models, lighting etc), probably not, however, re-rending would allow for higher resolution (1080P or cinema resolutions) and higher frame rates (not sure what blu-ray does in terms of frames), as well as tiny adjustments for display on modern cinema screens and TV's.
- kstenerud 13y agosigh WHY has he locked the font size down on his blog such that CMD + and - only change the text area width and image sizes?
- cheald 13y agoIt works just fine in Chrome and Firefox here. Are you perhaps using an old and/or awful browser? He's using a px unit on his font size, but Firefox and Chrome have done full-page scaling for ages now.
- kstenerud 13y agoI'm using the latest chrome for mac. I tested on a different blogspot blog and it works perfectly there.
- jtchang 13y agoI suppose the holy grail is when ray tracing can be done in real time. At that point things would look so real we might as well call it quits from real life.
- planckscnst 13y agoI'm guessing the disco ball scene is Pixar flexing their muscles with the new tech. It's pretty impressive.
- pygoscelis 13y agoHere's a paper from last summer on how Pixar is doing the computations for global illumination more efficiently with a "multiresolution radiosity caching method." http://graphics.pixar.com/library/RadiosityCaching/paper.pdf http://graphics.pixar.com/library/RadiosityCaching/paper.pdf I don't know much about graphics but maybe some of you will find it illuminating (no pun intended....)