Prevising 2012's 'Yellowstone'
A key sequence in director Roland Emmerich's 2012 features the eruption of Yellowstone National Park as the stars of the film flee via a Winnebago and, eventually, by plane. Previs for this 'Yellowstone' sequence was undertaken by Image Engine in collaboration with the film's overall visual effects supervisors Volker Engel and Marc Weigert. With 2012 now out on DVD, Image Engine's previs technical supervisor Cameron Widen and VFX executive producer Shawn Walsh talk to vfxblog about their work for the sequence and about their previs philosophy.
Download Image Engine's 'Yellowstone' previs (122MB)
Download the Sony Pictures 'Yellowstone' featurette featuring final shots (42MB)
What kind of setup for previs do you have at Image Engine?
Widen: Well, currently I'm the sole previs artist on staff at Image Engine. We have a couple of contract guys who are our go-to people because they are familiar with previs and can really embrace the crazy situations that previs brings to us sometimes. Then we'll get other freelancers and people from the studio to fill in other roles as needed.
What technology do you rely on?
Widen: We're Linux based. We work in Maya and then depending on the needs of the job, sometimes we'll be doing some compositing with Nuke, sometimes some match moving using pfTrack. We edit on a Mac laptop or workstation. We use a bunch of proprietary tools from our VFX pipeline for the previs - things like tools to turn our image sequences output from Maya into QuickTimes that the editor can work with.
Are you doing both standalone previs work or previs for shots that Image Engine will eventually do the visual effects for?
Widen: Ideally, the company will send us out on location, we'll previs certain sequences for the movie with the idea that we'll get some name recognition and face recognition and that will parlay into some post work - this happened on the upcoming Twilight: Eclipse. Quite often we do previs independently of the effects work.
What do you see as the benefits of previs?
Widen: I think previs sits at the whole centre of the entire spider-web of the pre-production pipeline. So when we were working on Twilight, we were co-ordinating daily with the stunts people who also gave us video so we'd know what action they were planning. We're also closely tied in with the art department so that we can make our previs setups in 3D look like the concept drawings they create. And we work closely with the director, but the person we're most answerable to is the VFX supervisor and the VFX producer. The benefits to the supervisor, of course, are that they can plan out how these things will be achieved in post once the shooting is complete. The benefits for the producer are that they can look at a whole sequence and fine tune their budget on a per-shot basis. For Twilight we were dealing with wolves and vampires and they needed to know how many wolves were in each shot and how many shots contain wolves, so they could budget the post work.
How did you get involved in 2012?
Walsh: At Image Engine, we wanted previs to be a more dedicated service. What we tried to do was wrap previs up as an overall department in a visual effects business. We wanted to treat it as an entity to a certain degree, but culpable to the main business. What we hoped would happen was that a client would engage us in an R&D task such as building a fur pipeline or doing the werewolves in Twilight, they would also engage us in previs for visual effects shots that we would ultimately work on. For the most part, that overview has happened in bits and pieces. And now people are starting to look at us after District 9 as a studio that can handle a broad range of work and tasks, one of which could be previs.The majority of the work that we've done has been pure contract previs work, like for 2012. There were a huge number of shots. Roland Emmerich's view was that he wanted to use previs to a technical degree to a certain extent, but it wasn't really the main goal. The main goal was understanding the scope and breadth of the sequence, and understanding how far he had to go in certain shots, creatively, to achieve the story point - how many of these huge shots did he need to get across the absolute scale and magnitude of this cataclysmic event?
We really took that sequence much beyond what a normal previs sequence would do, almost to partial look development so that when Volker and Marc were talking to others about the sequence they could really explain visually what the sequence was, literally down to the number of meteorites that were landing in the backgrounds of shots.
Did you look to any particular concept art or storyboards for the previs?
Walsh: There were a handful of what I would describe as loose 2D concept paintings that showed the general gist of things. Then there was some specific talk about Yellowstone itself and the structure of the park and the topology. We did receive some location information about the town they were going to shoot live-action for this in British Columbia, where there's a very similar geographical look. Some of that layout ended up making it into our previs.
Widen: We were given a concept painting of the Winnebago driving down the road with a lot of meteors around it. We were given some photos of the area so we knew what the terrain was supposed to look like. We had some rough 2D storyboards and we were given a collection of videos of nuclear blasts, landslides and things like that for reference of the feel if not the exact scope for the sequence. The previs was done at a pretty early stage of pre-production, so we were helping them figure out what they would need to shoot and what would be CG.
How did you get started on the work for 2012?
Widen: The brief we were given was that it was all going to be screen-grab visuals. We were mostly going there to rough out the story based on the script and the storyboards. Over the course of working on it, showing it to Roland and Marc, it became clear that we were actually also doing look development for them as well. Things slowly morphed from just doing rough animation and figuring out camera angles to making it look as good as we could, which was not part of our original plan. So the result of that was that we went from a crew of five previs generalists working on animation and editing to getting in two dedicated effects animators and a dedicated compositor. We had to get the IT guys here to set up a fully fledged renderfarm for us. We got into doing depth of field for a lot of the shots. None of this stuff is beyond our capabilities, especially for a VFX company, but when we went out there initially we were setting up for a previs job.
Can you talk about the to and fro process with the VFX supervisors?
Widen: The way we always think is to treat previs as a process, not a product. Previs is something that's continually ongoing, continually morphing. It has to be agile. We have to be able to change things quickly on the fly. When we're working with someone like Roland, it's constant back and forth.
Walsh: It really depends on who the client is and the goal. Previs roughly breaks down into three categories. There's technical previs which is really taking some existing creative work and analysing it for technical data so that multiple plates can be shot correctly or things that need to be shot on different lenses can be shot directly. The second one is exploratory or creative previs where a director wants to try some things and is uncertain about the best way to capture a moment. It's just a first pass at something without wasting money on a shoot day. The third one is more of a marketing tool, where you might take the creative previs and show it to an executive so he or she can get on board with what the film is trying to accomplish creatively. Usually the previs jobs are some percentage weightings of all those things.
Even though the previs department at Image Engine is a relatively small part of the company, one thing the whole studio has acknowledged is that previs is about engaging long-form storytelling content and enabling that process. Really, visual effects is part of the same game, just at a different part of the process. When a project is at its most fragile is often when previs comes in to put images to words. The sensitivity that that requires has to come from a company that does long-form, narrative and storytelling skills. By bundling those skills into a visual effects company, we can draw skills from elsewhere. So there's been a lot of times we have Cameron as the supervisor and people are swapped in from the other visual effects talents in the company.
It seems to me that the previs really helped with the storytelling process early on. How did you deal with the editing of the sequence?
Walsh: One of the things we did on 2012 was to employ a second supervisor who was kind of an animation director/editor. It was Zeke Norton who directed the sequence and edited it to make sure that creatively the beats were being hit, while Cameron took care of running the crew and the technical kinds of things.
Widen: For a job as huge as 2012, it was really important to have the division of labour that way and having someone else dealing with the editing, story points and integrating with what the director wanted.
Walsh:The biggest thing creatively for the crew was that the sequence was all about destruction and the entire environment in Yellowstone being destroyed by a single event. We did a lot more dynamic simulation, particles and working with elements than you would normally do. We tried to use cheap but effective element library compositing that got a lot of visual detail into the previs without it being too cumbersome.
Widen: It came down to what previs normally comes down to which was cheating the hell out of everything we can and getting the most visual impact from the lowest computer requirements. There's a big pseudo-nuclear explosion that goes off, and to get that we could have spent days simulating fluid effects to get it to look right. But instead we got some clips of 1950s nuclear tests, did a big roto on the mushroom cloud and comped that in on top of our scene.
Walsh: It's really effective. If you're in a visual effects company, you have the perspective of 'doesn't really matter how you get to the end goal, you just have to end up with someone the director wants'. So the solution for the mushroom cloud might not have been so obvious for a company that doesn't, say, employ as many compositors.
Was there ever a call for you to add technical details such as lenses to your previs?
Widen: We weren't asked to come up with any of that technical data. This one was pure creative/visual previs.
Walsh: For this sequence, the data that they could have pulled from it would have been useless because there were helicopter shots and so on. So really it was more explanatory in nature. They knew they would go out and show the crew so that when they shot the scene they would know how it would look. Our sequence ended up being quite a bit longer than what ended up on screen. They tightened things up a bit.
Widen: But there is a very clear translation from our previs to what ended up in the film.
Walsh:You would normally expect it for a more 'technical' previs, but I think they crew did an amazing job of matching what was in the previs, given they were doing so much helicopter work. A large degree of the credit goes to Marc and Volker who were shooting a lot of second unit.
Do you know how the previs ended up being used either for the shoot or by Double Negative, who worked on the final shots?
Walsh: I think it ended up on a laptop. Some of our colleagues at Dneg said it was viewed extensively over there.
Widen: That's why we spent a lot of time making it look good. Obviously it's previs so it's not photorealistic, but it was useful for figuring out the scope of things - how many lava bombs are happening, how big the explosion is, what it generally looks like. The reason they got us to go as far as we did was because they wanted to plop it on the effects artist's desk and say: 'Make it look like this, only more real'.
Walsh: We're very passionate about having a very thriving previs department. It gives us a nice perspective on the filmmaking process and the visual effects work. The learning by osmosis part of that is fantastic and you get to meet a lot of the folks who are pushing visual effects very hard. I always say to the junior people who want to get a start in visual effects is that in previs you get to work on all the cool shots.
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Previs video courtesy of Columbia TriStar Marketing Group.
