2012 uses Bullet
This article on digitalcontentproducer.com gives an interesting insight into the special effects in ‘2012’. A *huge* surprise: they built part of their simulation software around Bullet – the open source physics simulation engine that’s also part of Blender.
It’s a great news for the Open Source community:
This challenge led DD [Digital Domain] to develop a new simulation system called Drop. “Our software team built it around a fast, open-source engine called Bullet,” Leo says. “Bullet was the core solver, but we established a system for generating and breaking constraints and for assigning material properties to objects. That allowed us to do things that are very difficult for rigid body solvers, such as concave objects and organic shapes where collisions become very complicated. Drop is tremendously fast, and it allowed artists to iterate on a fairly long simulation in an hour or two. We were able to simulate tens of thousands of colliding objects.
Links
That’s another sign that Bullet must stop being constrained to the BGE only and leap into “general physics simulation” for Blender.
Bullet can be so useful for Armature ragdolls, realistic object movement, cameras motion, destruction…
Something like rayfire is within grasp of Blender’s animators if Bullet can finally act outside of the BGE.
With options for changing timesteps for kick ass “slomotion” effects…
Wonder if project Durian will bring anything new on this side… I hope so :)
> That’s another sign that Bullet must stop being constrained to the BGE only and leap into “general physics simulation” for Blender.
Wot aws357 said!
That movie was visually beautiful. It’s awesome that some part of blender was involved.
There’s a branch added not to long ago (2 weeks?) for getting bullet into blender.
*edit* check: http://lists.blender.org/pipermail/bf-blender-cvs/2009-November/023608.html
Here for the integration design doc: http://wiki.blender.org/index.php/User:Kazanbas/Bullet_Proposal#Integration.
According to his latest svn post things are moving (literary) http://lists.blender.org/pipermail/bf-blender-cvs/2009-November/023698.html
IIRC there was a branch added not to long ago (2 weeks?) for getting bullet into blender.
*edit* here it is: http://lists.blender.org/pipermail/bf-blender-cvs/2009-November/023608.html
and here for the integration design doc: http://wiki.blender.org/index.php/User:Kazanbas/Bullet_Proposal#Integration.
and according to his latest svn post things are moving (literary) http://lists.blender.org/pipermail/bf-blender-cvs/2009-November/023698.html
but bullet is designed for realtime physics. it cheats the laws of physics with many tricks for achieving better performance (with a linear solver).
one limitation is that it only allows for very limited mass ratios between bodies. 1:10 or so.
and i think friction isn’t very realistic either. on huge stacks you can pull out lower boxes as easily as upper boxes for example.
so i wonder why they didn’t choose something more appropriate?
Bullet is no more Blender only physic engine, it’s also a part of Maya Dynamica and C4D MoDynamics
http://bulletphysics.org/wordpress/
And sure dd used bullet, as bullet is now a DOP for sidefx houdini & dd loves it !
http://odforce.net/wiki/index.php/BulletPhysicsRBDSolverDOP
http://forums.odforce.net/index.php?showforum=58
Are Digital Domain feeding anything back into the Bullet project, patches, additions?
Brilliant advertisement and prestige for Bullet.
@horace: “Appropriate” is subjective. They chose to incorporate Bullet. It worked: it produced the visual results they wanted and it did so quickly. Therefore, the choice of Bullet was appropriate.
Good news. Too bad that the only good thing about the movie were the FX :/
@aws357, yep, my sentiments exactly!! Great article and another reminder that Blender is using the right stuff!!
This is amazing!… glad to see open source options beign used for important projects… however… was Blender really used? im under the impression that they could have used the bullet plugin with another software… am i mistaken?
@Horace, everything in CG is a cheat :)
i understand your point, but as with everything in CG things have to LOOK realistic. so when a simulation with bullet doesnt look realistic the artist can tweak it.
an ‘unbiased’ simulator would give more realistic results but at the costs of simulation time. and with effects being tweaked all the time this would waste to much time.
@Yellow, i certainly hope they support Bullet and supply some patches, but the Zlib license of Bullet doesnt force them to do so (AFAIK)
They always saw, oh yea custom + x, or y or z.
Chances are it was straight out of the box. Normally it always is.
WOW! Cungratz to Erwin !!! :-)
@horace
Bullet is designed for realtime physics in games and movie FX, and there are approximations indeed. But most approximations in Bullet can easily be tweaked and improved. For example, you can increase mass ratios by decreasing the time step and increasing the solver iterations. And you got confused about the friction model: Bullet’s friction is based on the normal force, so lower boxes won’t be easily pulled out as upper boxes.
@Joel:
Most game/movie Companies who use Bullet contribute back in one way or the other, even though the ZLib license doesn’t require it indeed. In fact, if Bullet would have used the (L)GPL license, many companies would have ignored it. Their main developer (Jafees Bin Zafaar) helped with the open source Houdini plugin (BulletPhysicsRBDSolverDOP).
And advertisement is a great contribution too, so thanks 2012 and BlenderNation for reporting this :)
JotaSolano: blender was not used; the same physics simulation engine (bullet) was used to create “drop”
@RH2… thanks for clearing it up 4 me :)
Saw this for my birthday; did not want to wait for the DVD but instead get the big screen effect. +1 Guy said. The Visual FX were simply astounding. In HD, seeing the fracturing of glass buildings and tracking individual shards of glass (and other objects) was amazing. The lighting, compositing, fire, fluid, … great job all the companies that contributed.
That’s fantastic news and I must say, I’m more than a little surprised at this. Blender’s getting more use everyday it seems like.
“””And you got confused about the friction model: Bullet’s friction is based on the normal force, so lower boxes won’t be easily pulled out as upper boxes.”””
did this change in newer bullet versions? since if i remember correctly this wasn’t the case when i tried this a while ago.
No amount of rendering time or a number of layers or frame size can make up for totally crappy actor play and totally idiotic script. This is another doze of american bullshit crap. It is always the same and hollywood asshole idiots do not seem to get it, that the rest of the world does not buy any of that american bullshit anymore. American bullshit empire is going down fast and there will be a lot more shit like that 2012 coming to theaters near you. The priests of America even invented swine flue to take some of the attention from the total collapse of american bullshit economy and bullshit society. Maya priests at least had basic common sense that everything comes to an end, but american priests of pseudo democracy and bullshit economy seem to be in denial of basic common sense.
name: thanks for the laugh :-) American preist made the swine flue haha
@Nokadota
It was not Blender that was used, but the Bullet simulation engine, which the blender game engine uses. This is nonetheless great news!
That movie was visually breathtaking, in the truest sense of the word, and as soon as it’s available on BD I’ll grab the most limited edition available. It makes me proud to be a Blender user and it produced an endless flood of “how to” questions. The cresting waves most of all. I never thought I’d see anything that close to reality, and the use of Bullet shows that great things can be achieved through people’s good will (thanks to the Bullet-Boys!!!) and – indirect – love for each other.
@name: maybe not such bullshit after all. Research “Chabad”, “Pentecostals”, “Sufism” and “Armageddon”. The only essential part of the story that was BS was the World Elite gathering on those arks WITHOUT labour slaves…. that was most unrealistic. And the President staying with the dying crowd… *LOL* And the Elite not having soldiers on board of the arks shooting everyone jeopardizing their mission of recolonizing “their” new planet with their noble, chosen blood ;) Very naive. But awesome visuals!!!
“In fact, if Bullet would have used the (L)GPL license, many companies would have ignored it.”
Funny how companies will contribute fixes back to open source when the license doesn’t require it, maybe the hype over copy left is just that? Hype, just like the premise behind the film…
@No “Name”
I’ll say this firmly but fairly. You are posting on a blog for Blender, which is GPL’d. This article is about a Hollywood movie, which is almost guaranteed to have Linux (and GNU, etc.) in its render farm and pipeline, which is GPL’d. You seem to want to portray copyleft licenses as a failure because for-profit companies might want to use the codebase and make a proprietary derivative. The ENTIRE POINT of copyleft is to license the software and any derivatives as non-proprietary. Like any other software, if you don’t want to abide by the license, then don’t. Use other software. In the case of Bullet, if it were GPL’d and Digital Domain were prevented from making a proprietary derivative that it would REDISTRIBUTE, then the license is 100% achieving its goal. It is 100% success, not a failure. On the other hand, if they don’t want to redistribute, then the GPL allows this anyway. If Digital Domain were generous and willing to contribute their modifications back to the community, then Zlib or any non-copyleft license is irrelevant as the GPL would not have deterred them from making contributions because they were going to anyway. You have a right to your “opinions”, but please stop harmfully slandering the hard work of others and educate yourself on a subject before you communicate your opinions.
it is like me with the starwars trilogy i watch it almost everyday…and learnt it by heart…and yet it is full of clichés and stereotypes…racisme…ethnically viling and so on…politically full of propaganda…with laughable dialogues…and yet because of maya still visually enjoyable…strictly because of maye…btw jarjar binks is my favourite charactere
Often times, studios that use these core technologies (bullet, ODE, etc…) would have a hard time releasing them to the community. They are often so interconnected with proprietary systems, code trees, network setups, etc… to make it all but impossible for it to even work outside of the studio.
Still, here’s to hoping they actually do it someday.
@cdah
It already happened twice:
The 2012 developers helped with the Houdini plugin BulletPhysicsRBDSolverDOP
Disney Studios open sourced their Maya Dynamica plugin to the Bullet project
(just google for both or visit the Bullet website)
what are the benefits of the maya dynamica plugin? i always was under the impression that its native physics solution is one of maya’s strengths? just curious…
@RobW
I don’t agree. The Zlib license helped Bullet getting a foot in commercial game and movie companies, because it is not copyleft. In practice, many companies avoid embedding (L)GPL middleware libraries into their own projects, because they want to keep the option open to collaborate with other companies. They don’t like the viral copyleft strings. 2012 was not made by a single FX company. They might want to distribute their Drop Houdini plugin with partner companies, without being forced to disclose the full source code to those partners.
For game engines (Bullet primary target, movies are secondary), the (L)GPL license is even less attractive: many publishers even don’t allow usage of (L)GPL. There is a reason why Ogre recently switched from (L)GPL to MIT.
Obviously (L)GPL works fine for modelers such as Blender or operating systems such as Linux any many other purposes, but when you target movie and game middleware, BSD/MIT/Zlib is a better choice in my opinion.
@horace
>>did this change in newer bullet versions?
The various friction models and settings have been there for a while.
>>what are the benefits of the maya dynamica plugin?
Dynamica seems faster and more scalable and the movie company can customize/tweak/extend its features easier than Maya’s built-in closed-source solution.
If you want to continue this discussion, please do so on the Bullet physics forums :)
By the way, I want to mention that some credits have to go to Blender, because it provides an excellent environment for our experiments with Bullet.
2012 is a pretty boring movie. About 1.5 hrs of carnage, that it feels like I’m watching a physics destruction simulation.
This is probably the greatest physics demo for any physics engine out there. Both in terms of cost production and length. =D
@Erwin Coumans
I agree that there are reasons for choosing copyleft versus Open Source versus proprietary. There are times at my own company I work at where I’d choose BSD over GPL (but not necessarily LGPL). That is a FAR cry from “No Name’s” post that copyleft is all “hype”, don’t you think?
In regards to your post, I’ll reiterate what I wrote earlier. If DIgital Domain intends to *redistribute* while keeping the code proprietary, and the GPL or LGPL prevents that, then it *did its job*. In such a case, use software licensed under Zlib like Bullet or another open-source but non-libre project. If they don’t intend to make a proprietary derivative, or in fact wish to place some of the development burden to the community at large, then they can do that with a copyleft license. I don’t know why people have this idea that if a for-profit company doesn’t choose a copyleft licensed software in absolutely *every* case, that somehow that is “proof” that such licenses have “failed” in some way when the entire point of the license is different than other licenses.
Before this degenerates into a long series of posts and semi-flamewars or such, let’s please just settle on this:
1. The specific case of Digital Domain’s use of Bullet has as much to do with its technical merit (e.g. fast performance) as it has to do with the choice of licensing. With enormous budgets, they could have chosen alternatives, either proprietary or other licenses that allow proprietary derivatives such as the BSD license. For example, why not ODE instead of Bullet? ODE is under the BSD license, not GPL.
2. If you don’t like copyleft or have no use for it, fine. But it exists because there are licenses for proprietary and for Open Source that allows proprietary derivatives, but some people want to have a license that ensures that their projects and its derivatives *remain* non-proprietary. Without the existence of a copyleft license, they lack that choice.
3. Just because I contend that copyleft is “not hype”, is not implying that other licenses “are hype”. Choose whatever license fits your needs. My posts are in context of “No Name’s” claim that copyleft is hype.
I apologize for the additional post, but the blog editor didn’t let me edit my previous comment for some reason.
I’m sorry for the people who are getting fed up with this licensing discussion, but I think it is very relevant in a topic about open source being used in a commercial project :-)
@RobW
We mostly agree, here are some answers to your first question:
Re 1: Zlib, MIT, BSD are similar licenses, so they could have chosen ODE but there are 2 issues:
1A: Unfortunately ODE’s convex collision detection is broken (very important for breaking/convex decomposition), and Bullet has a better iterative constraint solver with features such as warm starting.
1B: The Zlib doesn’t require the user to attribute/acknowledge/give credits that you used the software.
With MIT and some BSD versions you are forced to mention used in the documentation or give credit, and some companies avoid software because of this requirement.
Hopefully this shows how the Zlib license helps acceptance for middleware libraries in the games/movie industry, where (L)GPL frequently does its job of preventing so. Especially for projects that prefer to stay proprietary.