Exclusive Interview: 2012‘s VFX Geniuses Reveal How They Flooded the Himalayas (and Sent That Poor Monk Scurrying for His Snorkel) (Part 2)

Share on Facebook posted 11-10-09 by John Freeman Gill

You may have seen the sequence in the 2012 trailer: High atop a Himalayan mountain, a red-robed monk, enjoying the crisp morning air and the serenity of his chosen profession, rings a solitary bell in a Buddhist temple. The next moment, before the poor holy man can even begin to ponder where he might find a snorkel shop at 23,000 feet, the entire mountain range is deluged by a tidal wave so epically gargantuan that the only plausible explanation is that God fell asleep in the tub with the water running. A preposterous sequence, right? Sure, but those who have seen 2012 tell us that this apocalyptic flood is rendered so convincingly that you completely buy its authenticity.

In Part 2 of our exclusive interview, Marc Weigert and Volker Engel, 2012‘s co-producers and visual effects supervisors, tell us how they pulled it off.

How to Make a Visual Effects Supervisor Sweat

30 NINJAS: I’ve done some screenwriting, so I know how easy it is for a writer to imagine something, and write it down, and say, “Boom. There it is.” But you are the poor guys who have to actually implement a writer’s and director’s vision. So I was wondering, what was the line in the script, or the visually dazzling scene you read where, more than any other, the moment you read it for the first time you said to yourself, “That would look amazing if we could pull it off, but man, how the hell are we gonna do that?”

VOLKER ENGEL: (laughs) Yeah, there was definitely something in the third act of the movie, where the Himalayas are being flooded by this gigantic wave. And it’s just something about this size that when you read this for the first time on the page then, as a visual effects supervisor, you might start to sweat a little bit. (laughs) Because it’s not just, you know, water rushes through the street; we’re flooding the highest mountain ranges of the whole planet.

30 NINJAS: You worked on that sequence with a visual effects house called Scanline, which has some proprietary effects software called Flowline. What did that software allow you to achieve?

MW: The technology they have is, I think, unique, and they’re the only house that could have pulled of what we needed here. The Flowline software has been in development for, I think, about 20 years now, and one of the most difficult things today to simulate still is water, for the main reason that water consists of so many different things: You first have the actual body of water, so to say, the water mass. Then, when water hits anything, it literally splits up into different arms and tendrils, and from that it forms the foamy whitewater, that also is all over the surface of the water and reacting to each other. And then from the whitewater comes the soft mist that is hardly visible. So you’re literally dealing with three different types of elements and simulations that are extremely difficult to do on the computer. And the larger scale you go, the worse it gets — that’s where your limitations are, and that’s where ours were.

Water, Water, Everywhere

30 NINJAS: And these big disaster scenes in 2012, many of them, are all about water, and lots of it. Oceans of it.

MW: Yes, exactly, because today, you know, you can do computer-animated water or someone pouring a glass of wine, that’s not a huge deal anymore, you can do it in a few days. But, if you get to a wave that’s one mile high, that’s a totally different issue suddenly, to get that scale. So what they’ve developed is a software that can … you know, there’s always two steps involved in that: You first have to do a physics-based simulation of particles, so you basically throw out a bunch of dots, and make those react to the environment, and that’s called a physics-based fluid simulation, that simulates how a fluid with a certain viscosity reacts to an environment when you throw it out, of a bucket, or in this case a bucket that’s a mile wide. That’s the first part. So first you have to simulate that. You also have to simulate all the other parts separately: the whitewater, the water foam, the mist. So the physics-based simulation is number one. Then you have to mesh it out, so you don’t have a bunch of dots on the screen, but you actually have the water as one big body that’s moving fluidly. Then it has to be textured, or in this case shaded, so it actually looks like water. And you know, water’s half see-through, in certain areas. Not always. If you look at a major body of water, you don’t see anything through it, but as soon as the water comes becomes very thin and goes along the mountains or something like that, it’ll become see-through. So it’s a lot of different things: the way it reacts to the sunlight and so on. Then, once all that is done, you have to render it frame by frame, to actually output it as an element that can be used to composite into live-action, or whatever you need. And the software they wrote handles these things and makes it possible to even do because it uses all the processing power. Here’s the thing: Most software today works fine on a single machine, but you cannot split it up across multiple machines. So what happens is, a simulation like that can take five or six days on a single machine, so after five or six days you suddenly see, Oh my gosh, it’s no good at all. So then you do it again, another six days, and you can have weeks and weeks go by until you have something that’s kind of usable, and now you have no time to change it again. So what they developed is, they can split it up among as many processors as they want, so now you can put a thousand computers in there, and suddenly it’s not 15 days anymore, it’s 15 minutes.

30 NINJAS: You’re literally using a thousand computers?

MW: They used over a thousand processors. But close, actually; I think they had 600 computers.

30 NINJAS: So 600 computers, each doing a different part of this simulation?

MW: Yes, correct. And we’re doing the same thing with rendering, actually. We alone, also our in-house unit, had close to 500 computers for the Las Vegas sequence and the Los Angeles limousine. And today, you know, they all have eight cores, so you’re really looking at 600 computers times eight cores in terms of processing power. And so now we have a fairly fast turnaround, and you can see a new version within a day or two, rather than waiting a month. And that gives you a lot more options to art-direct it then, and creatively work on that to get the scale 100 percent right.

Read Part 1 of our exclusive interview with 2012‘s VFX wizards to learn how they trashed the planet in 1,315 simple steps — and how far visual effects have come since 1996′s Independence Day Read It Now!