The water technology behind Avatar: The Way of Water
blog.unity.com
blog.unity.com
One of my favorite TV shows as a kid was Movie Magic. Back in the 90s, most effects were practical, rather than CG, and it was interesting to learn about the various techniques used to achieve the results. From matte paintings, foley sounds and miniature sets, to animatronics and pyrotechnics. There were entire industries dedicated to this, which were replaced—practically overnight—by computers.
While there was a rough patch of awful CGI in the 90s and 00s, and the tech has certainly come a long way since then, even today, a discerning viewer can still tell CGI apart from live action.
I feel like we lost some of that "magic" in the process.
Consider the animatronics used in Jurassic Park[1] and Free Willy 2[2]. They might be crude, stiff and surely very laborious and expensive to build, but the result on screen was much more impressive than today's state of the art CGI. Maybe we've been saturated and take VFX for granted today, but it's a shame that some of these practical effects didn't continue to improve, and are rarely used in modern films.
I appreciate all the work and dedication of those folks, but it feels like such a waste. Especially when the final film wasn't very good.
The craft is admirable, but it was never scalable or equitable. Very few projects could benefit from this kind of budget and vision.
The coming AI revolution will make this vastly cheaper than even CG, and it'll give more people a hand at storytelling. Without requiring fifty engineers a full year of their talents.
And I actually didn't mind, the CGI was gorgeous.
It's a story about spirituality and nature and community and family that explicitly advocates for eco-terrorism against the American government.
But none of that matters because they are blue, lol. People aren't blue. How silly.
It’s a _clichéd_ story about all those aspects. “We are a family” or a variation thereof is the most repeated sentence in the movie. The evil guys are evil, 100%, no nuance.
My humble opinion is that the movie is visually stunning but too predictable, but I’m not a fan of most movie where “things go boom” or “fighting to death” is a substantial component of the plot… so there’s that.
I explained why to me it was a boring three hours in a very comfortable movie theatre armchair, so that you see why some people didn’t actually enjoy it as much as you did. On the masterpiece part, I’ll agree to disagree :)
You seem like a very shallow person if you think these films are any good.
After a quick read of critic and user reviews through metacritic, the complaints seem pretty consistent regardless of how I personally feel about them. A ton of them say the plot was barebones and predictable. Even the glowing reviews from critics seem to mention that the plot only gets the job done.
Once I understood that in both cases the story is there just so Cameron can do his worldbuilding, I enjoyed both films very much.
A2 is a different beast. The conflicts in A2 can be described as:
- Quaritch captures kids.
- Quaritch: Sully, come alone and surrender, or I kill your kids.
- Sully doesn't come alone and doesn't surrender. Quaritch leaves kids alone. Quaritch's men die, kids rescued.
- Quaritch captures kids, again.
- Quaritch: Sully, come alone and surrender, or I kill your kids.
- Sully doesn't come alone and doesn't surrender. Quaritch leaves kids alone. Quaritch's men die, kids rescued, again. One dies from battle wound.
- Quaritch captures kids, again.
- Quaritch: Sully, same deal despite everything, come alone and surrender, or I kill your kids.
- Sully doesn't come alone and doesn't surrender. Quaritch leaves kids alone. Quaritch's men die, kids rescued, again.
If you can stomach Quarich being okay with being reborn into the thing he hates the most, or everyone important that died in A1 being reborn, or the fact humans don't simply nuke the Navi from the orbit, or the fact that unobtanium is not as important as miracle whale oil, .... then Quarich bluffing and being called on it and then trying to repeat the bluff is not SO far fetched.
Edit: I can’t find this talking point on the internet in the usual places anywhere.
At this point, I think that while Cameron has great visual taste, he simply just doesn't have any literary taste at all. I believe he actually thinks these horribly banal, cliched stories are genuinely good.
It's gotten so bad that it makes me retroactively wonder whether he actually wrote "Aliens" and who the real author is.
I also contest your assertion that the results are more impressive than todays CGI. That’s some rose tinted nostalgia, but there’s no way to replicate some of the advanced motion and realism like the latest Planet of the Apes or Avatar with animatronics. The range of motion required is just not safe to do or cost effective.
Safety is a big one. Having an animatronic T-Rex chase a car at speed in the rain is not physically safe to execute in the same space as your main actors. The requirements are at odds. To work in rain requires materials that are hard to move, to move fast requires lighter materials and heavier motors. All of that is a giant weight hurtling at your talent. Use of lighter materials also makes them less durable or more expensive.
Furthermore, most animatronics and practical effects in film today are replaced. As much as people sell the allure of “this film is done practically”, the majority of it gets replaced with CG in post. The new star wars films tried that angle with BB-8 and Top Gun Maverick claimed the same, but they practical elements people laud were CG in the final film.
It can require a different toolset when it's just you and a blue screen, but in many ways it's the same craft that every actor develops anyway.
The point is that actors are used to imagining things. Ian McKellen didn't need an animatronic Balrog; he had no trouble delivering his lines to a tennis ball (which told him where his eyeline should point). It's all in a day's work for an actor.
It does put requirements on the director to visualize the scene for the actor. You can see that fail in Phantom Menace, where very talented actors deliver terrible performances not because of the blue screen but because they were given no direction. The director's job is always to convey what the actor needs to give the performance they want, and that can be nothing more than words.
Sorry, despite your nice exposition I still don't believe it. If you really think a blue screen doesn't negatively impact acting performance then it would require some kind of scientific experiment to convince me.
One person is clearly talking from experience of working with actors here (if you’re unaware of the person you’re replying to)
Yes, it is clear that the person I'm replying to has more experience in this field; I'm just a "simple consumer" of movies. However, having experience can sometimes blind you from inconvenient facts. I think the burden is on the industry to prove that new technologies have no negative effect on the end product.
Audiences definitely like practicals, even when they aren't as realistic. People adore Baby Yoda even though it's obviously a puppet ... in fact because it's obviously a puppet.
They also react very positively to the Volume, which is so much better than blue screen even though it's just as fake to the actor. (They're usually not even looking that direction.)
It's an art so the techniques that work are the ones the artist chooses. I'm sure there are some who are happier with an animatronic and others who would just as soon scream at a production assistant on a ladder.
James Cameron & Denis Villeneuve on 'Avatar', 'Dune', and Pioneering CGI | Directors on Directors https://youtube.com/watch?v=RgZQK7cfx_0?t=14m30s
(It also leads to directors abusing that privilege, getting "real" emotions in highly negative situations. Like the way Shelley Duval was reportedly terrorized by Stanley Kubrik while shooting The Shining.)
The director has to assemble the team that they want, who will respond to the toolkit that they're using. In the end it doesn't matter what it takes, as long as you get the shot you want in the can. (And complying with ethics, a thing that has too often been ignored.) I'll sometimes even use the worst tool a director has, feeding actors line readings, though only when they ask and nothing else has worked.
Often, that’s better than animatronics because they can move faster and react to the actors better.
What is shot on stage doesn’t have to be what’s used in the film, and it’s a common mistake that people who are critical of CGI make.
I know it used CGI in some shots, but I disagree that these were the most memorable. Close-ups of the T-Rex, the creeping raptors in the kitchen, the sick Triceratops, the expanding neck frill of the Dilophosaurus, etc. These were the most tense and impressive shots IMO, and all were practical (even though they were historically innacurate). CGI was used mostly for wide shots that needed to show movement, which wasn't practical or sometimes even possible with animatronics.
> I also contest your assertion that the results are more impressive than todays CGI. That’s some rose tinted nostalgia, but there’s no way to replicate some of the advanced motion and realism like the latest Planet of the Apes or Avatar with animatronics.
I don't disagree that nostalgia is a big part of it, and the fact that back then these were truly ground-breaking shots we hadn't seen before. Each film did things slightly differently, and VFX weren't as accessible as today. Still, there's something raw and, well, real about an actual physical entity that actors interact with. The lighting and physical properties are always correct, and assuming the makeup and robotics are state of the art, it really can trick our brains into believing these are real objects much more than CGI could.
For example, take the sick Triceratops scene[1], and compare it to 2015's Jurassic World[2]. Sure, the CGI versions are more life-like, but they look completely fake. The lighting and shading is off, the interactions with the real world is limited and unrealistic, etc. In contrast, the scene from 1993 still looks impressive today, even though the movement is limited, and it arguably looks a bit stiff. State of the art CGI today is much better, though[3], but still slightly off in a few places.
This can possibly be blamed on "bad" CGI, but I'd argue most usage in movies falls into this category. Even the creatures in this new Avatar, while incredibly detailed and life-like, look artificial, and like they don't belong in the world around them (which is, ironically, also CG). It looks like an animated, instead of a traditionally shot, film. Which doesn't mean it can't be enjoyable, it's just a different experience. For me, it crucially lacks the awe-inspiring moments that films with practical effects often have. I realize that most of these shots couldn't be possible with practical effects anyway, but I appreciate when directors make an effort in using mostly practical effects, instead of defaulting to doing everything with CGI.
As another example, consider All Quiet on The Western Front[4]. According to the VFX lead:
> The overall VFX mantra was to allow the footage from principal photography to serve as the primary material for compositing, as opposed to creating CG elements in VFX to augment the scenes. “I believe that adds to the visceral, immersive quality of the film,” Frank Petzold explains. “So in other words when, say, there was an explosion scene, we did not entirely rely on CG models.” Rather, the team used photographic elements as the primary foundation, implementing CG simulations to augment principal photography. The effect was naturalistic, and the integration aimed to be seamless.
I think this is the right approach to take, and the film is much more immersive and enjoyable because of it.
[1]: https://www.youtube.com/watch?v=tYm7xeg27Rw
[2]: https://www.youtube.com/watch?v=2CJL7rKJI18
[3]: https://www.youtube.com/watch?v=le0iiWwdeeE
[4]: https://www.youtube.com/watch?v=hf8EYbVxtCY
[5]: https://www.fxguide.com/quicktakes/all-quiet-on-the-western-...
you’re also comparing things without considering how the process created them.
Avatar wouldn’t look any more real with practical work. It’s just not possible to make robotics today that can have that level of articulation and micro expression. the reason it doesn’t look “real” is because the film makers didn’t want it to look real. It’s meant to be fantastical.
You claim most CG is bad in films but I’d argue that you, like many others, glomp onto the bad CG and ignore all the fantastic CG that you don’t notice.
How many people do you think noticed that the entire environment they’re in isn’t real in these shots? https://youtu.be/V5mS7BHmZJI
Often what people consider “bad CG” is overly apparent CG. This can be down to three things:
1. Budget. Both money and time.
2. Deliberate Aesthetic choices
3. Directors often put CG more in your face than practicals
Practicals wouldn’t make a difference there because they’d fall prey to the exact same issues which is why they’re often replaced in post anyway.
Aesthetics are a big one. The visual style between the original Jurassic Park trilogy and the Jurassic World trilogy is different. The new trilogy is significantly more fantastical in style and lighting. This is why you can’t just randomly compare shots between different films. They’re created by different teams with different goals. You need to compare against the raptors etc in the same film or where similar choices were made.
When people say “I wish this was done with practicals”, what I think they mean is “I wish this was better” but ignore the why.
“Making of "The Hunt for Red October" - Behind the Scenes” https://www.youtube.com/watch?v=2_epfA20dOY&t=21m55s
“HUNT FOR RED OCTOBER miniature effects part 1” https://www.youtube.com/watch?v=V5Npc6GsUeQ
“HUNT FOR RED OCTOBER miniature effects (part 2)” https://www.youtube.com/watch?v=MGu8qcI7r-I
You can tell BAD CGI apart from live action.
Eventually, we'll reach a point when CGI truly becomes indistinguishable from reality, but even then I'd argue that using it for all aspects in a scene would undermine what makes the art of cinema "magic". After all, would it really be filmmaking, or animation, at that point?
1. The practical effects on Jurassic Park weren’t simply augmented by CGI. The hero sequences had the main set pieces as CGI. Please tell me how you’d do the T-Rex chasing the jeep with practicals? Or something like gollum fighting with Frodo ? Or Davie Jones in Pirates?
In fact, when Jurassic Park came out: the CG elements were the hero’s in the news. This retconning of saying the practicals were the stars is rewriting history to fit a personal subjective narrative.
It almost put Phil Tippet out of a job, if Dennis Muren wasn’t a great friend. The news cycles and hype at the time were around all the CG sequences and how it wowed audiences.
2. It’s ridiculous to say animation isn’t a form of film making. It’s possibly the most pure form of film making. You craft every single detail, and make every single choice along the way. this kind of puritanical thinking of saying animation isn’t film making isn’t constructive. Are you seriously going to say that Toy Story isn’t film making? Or The Lion King? The little Mermaid?
I'm really not. Of course sequences like dinosaurs running, or films like Avatar and LOTR couldn't be done without CGI. There's a reason these films weren't possible before CGI; the technology simply didn't exist to bring the author's vision to life.
> In fact, when Jurassic Park came out: the CG elements were the hero’s in the news.
Of course. Animatronics were nothing new, while CG of that level and scale was practically unheard of. I would still argue that those films elevated practical effects to another level, which should be equally lauded as the CG work.
> It’s ridiculous to say animation isn’t a form of film making.
That's not what I'm saying. I don't look down on it, and enjoy many animated feature films. What it is, though, is different to traditional film making, which puts it in a different category of entertainment. The production doesn't involve a physical set, live actors, cameras, makeup artists, and dozens of humans dedicated to capturing live performances. Instead it involves voice actors who mostly work in isolation, an animation director who mostly works with artists, and large teams of designers, animators, editors and technicians who bring the characters to life.
> It’s possibly the most pure form of film making. You craft every single detail, and make every single choice along the way.
Are you implying that traditional filmmakers don't? How is that constructive?
> Are you seriously going to say that Toy Story isn’t film making? Or The Lion King? The little Mermaid?
Like I said, not in the traditional sense.
My point is that once CGI becomes indistinguishable from reality, and most/all scenes are entirely created by computers, is it a live action movie, or an animation at that point? The line is already blurry today with movies like Avatar, but I still enjoy watching movies that make practical effects a priority, over those that liberally use it in every scene.
They don’t at anywhere near the same level of choices involved in animation.
That’s just the simple reality of making something that is a simulation. You choose the way light bounces even if it breaks physics. You can’t do that in real world content. You choose silhouettes and shapes that can’t exist in reality.
I’m not saying they don’t make changes. But your statement implied that Animation wasn’t filmmaking. It is. One isn’t better or worse than the other.
And CGI is already indistinguishable, when we give it both the budget and art direction that is required. It’s been indistinguishable for most non-biological things for a decade now. We can already make completely realistic creatures and in some regards, also humans. Humans are hardest to still do but creatures have had that milestone crossed ages ago.
The hurdle is having the time and desire to do so.
I think you are going out of your way to segment things, and place them on a ladder. These are all tools to make content.
Saying that CG is best when augmenting practicals is just reductive. Especially when you keep bringing up Jurassic Park where the CG elements were largely the stars, and practicals filled in the rest. Practical effects, CG in VFX, full on animated features…they’re all tools for a creative. They can all suck or be amazing.
This whole “practical vs CGI” battle is literally just a construct of marketing that people are fed as a form of virtuoso. The people who actually do the work aren’t concerned with this kind of putting one technique on a pedestal over another. They’re all just tools.
> This whole “practical vs CGI” battle is literally just a construct of marketing that people are fed as a form of virtuoso.
It's really not. I can have preferences as to which movies I enjoy more, can't I? _For me_, practical effects are just more enjoyable and immersive to watch. When CGI reaches that level of realism—and you're right that in many ways it already has—I would still appreciate the result more if I knew that the effects were done physically, with all the challenges that poses. With the advent of machine learning, CGI is being commoditized to a level where anyone can create high quality visuals. This is great in many ways, but at the same time, it requires a completely different set of skills, with arguably much less effort, and so I'll never appreciate it as much as the product done in traditional ways.
You're free to think otherwise, and that's fine as well. :)
Your latest comment also belies that you don’t particularly understand or appreciate how much work goes into making CGI. It’s not any less of an art form than practical effects.
The difference is that it gives a much higher degree of flexibility, but the artistry and technical ability required isn’t diminished in any form.
I think we will lose it at all eventually. Today's audience is not making a big difference between movies and computer games, so the current disgrace of Marvel comic movies is just okay for them (old_man_yells_at_cloud.gif)
The old concept of animating physical objects to make them look like they're inhabited by a spirit and behave/bleed like real animals has been absorbed into motion capture and animation rigs.
We also used to love seeing people grow into new behaviours like luke in star wars. He was awkward and unsure of how he should act, and he grew into his new role as a jedi. Another example was Alan in Jurassic Park guiding people through the park by behaving in a manner that wouldn't get everyone eaten. But it's common for people to understand how to behave in action films and real life. The demand to see people learn a new set of behaviours, isn't such a strong pull to watch movies lately.
I struggle to imagine what a new-and-improved look for animated bones and lifelike animatronics would be? An engineer could make them stronger, better, faster and move more smoothly, but the higher experience people could want.. I don't know what it could be.
Two people could get CS degrees and one ends up building UIs/forms in React the other is implementing “Lagrangian water wave simulation”
Just totally different worlds
I’m not sure if I would call movies and video games “niche”.
I'm looking at you Monster Hunter and also Blitzball >.>
I remember the Quake I water simulation, which I found amazing at the time. I knew water is hard to simulate, but understanding fluid dynamics and the above jargon seems hard to grok too.
Technology is built upon a stack of useful abstractions, and the ability to understand in deep technical detail the entire stack is a super power. There's no reason why computational physics shouldn't work the same way.
Blender has a FLIP plug-in I believe. The water in UE isn't great, but the "fluid flux" plug-in is surprisingly impressive for real-time water https://www.unrealengine.com/marketplace/en-US/product/fluid...
Computational Fluid Dynamics is a tricky area. The science (Fluid Dynamics) was worked out over 100 years ago, with the Navier-Stokes equations (3D partial differential equations). The engineering (the Computational part) is a whole bunch of complex and clever tricks, to overcome surprising problems like instability and dissipation, and often for some particular engineering trade-off (rather than being universally true).
Avatar 2 seems to use an underlying FLIP simulation for the water (which uses a (eularian) grid for pressure, and particles for movement), with cinematic tricks on top: foam, bubbles, and smaller (lagrangian) waves superimposed.
The Fluid Flux plug-in uses a simplified version of the Navier-Stokes equations, which represents the upward direction as an average - so it's 2D internally but looks 3D. It also just calculates once, instead of iterating. Both make it much faster. It uses this paper, which has several other tricks: https://matthias-research.github.io/pages/publications/hfFlu...
Over each video I get “This content is hosted by a third party provider that does not allow video views without acceptance of Targeting Cookies. Please set your cookie preferences for Targeting Cookies to yes if you wish to view videos from these providers.”
Here are the videos:
- “Loki: A unified multiphysics simulation framework for production,” presented at SIGGRAPH 2022 https://www.youtube.com/watch?v=_2TBvSnsLD8
- “Wave Curves: Simulating Lagrangian water waves on dynamically deforming surfaces,” presented at SIGGRAPH 2020 https://www.youtube.com/watch?v=FqCK5Gu-Op4
- Overview of “Guided bubbles and wet foam for realistic whitewater simulation” as presented at SIGGRAPH 2022. Video courtesy of Wētā FX. https://www.youtube.com/watch?v=60Dk5h_659s
Code:
for (const deck of __NEXT_DATA__.props.pageProps.entity.decks) if (deck.url) console.log(deck.caption, deck.url)