Children of Men VFX

Children Of Men : VFX Seminar, Norway

Transcript of a Talk I gave at the Digital Fiction Seminar in Norway 2007 :

Hello Welcome;

I’m here today to talk about the VFX work in the film Children of Men.

Any conversation about the Effects work in this film has to begin with a conversation about the directors intentions and the style of the film.

Essentially the film is a dystopian tale of a future without hope, it’s a social commentary which takes issues from todays world and projects them 30 years into the future. It’s a science fiction film with all of the design issues that the genre demands.

Alfonso wanted to design a future that hadn’t really been seen on film before, it’s not the future of blade runner or the fifth element. It’s a dirty future. It’s 10 years of technological development and twenty years of decay and neglect. So that the future of England looks a bit like the Gaza strip or falujah. I guess in a way it’s a future similar to Terry Gilliams Brazil, yet more gritty & realistic and not as stylised.

Alfonso and Emmanuel Lubezki had a very particular stylistic reference when shooting Children of men. They would always refer to the classic 1966 film the Battle of Algiers. This became our bible, it’s documentary style and gritty realism were a template for the look of Children of men.

Alfonso and Chivo created a shooting style that is centred on ‘realism’, everything is lit with natural looking soft light. Every shot is hand held. In addition to this Alfonso is as interested in the environment as he is in the protagonists, he paints on a big canvas which means that he wanted to shoot the entire movie on wide lenses. Every shot in the film is shot on either an 18mm or 21mm lens. On top of this, his quest for what he calls “moments of truthfulness” led him to shoot the film in very long takes, I think in the final cut there are only 460 shots in the film.

180 of which are VFX shots…

Needless to say these stylistic quirks (handheld camera, long takes, wide lenses) had a very big impact on VFX production, and conspired to make it a very challenging experience.

Com is in essence a big budget neo-realist, art house Hollywood movie. Which I think has to be a new genre!

The philosophy behind the fx design is that of ultimate realism in support of the story, the brief was that the fx must never become a spectacle in themselves, never draw attention to themselves but they had to act like a digital glue and hold the film together. I think at one stage of production we had an hours worth of the movie on our server making this a very digital movie.

And it’s this point that’s interesting. Digital artistry is a very young artform compared to the great grandfather of film, and it is not always well understood by non-practitioners but Digitisation has given the director so much more power over his film than he’s ever had in previous years that when you have a director that does understand both artforms, new story telling possibilities are created, the kinds of shots that we did could not have been attempted even five years ago, and would not have been conceived by a director that didn’t understand both worlds.

Alfonso understood what he could do with digital and knew what he wanted to do and so was able to achieve some incredible results.

VIDEO 1 : Play front of reel : fx only, no breakdown.

The FX in the movie fall broadly into 2 categories. Digital environments/ set design and digital transitions employed to create impossibly long shots.

Invisible transitions

I’ll start by talking about the digital transitions or invisible cuts or whatever people like to call them. There are a two of shots in the film in which the camera is immersed in an extremely complex piece of action for 5 minutes or more. Now there’s been a lot of talk about one shot deals, there were no one shot deals in this film. These shots were far too complex to achieve in one shot or even in one days shooting. They were months in the planning and took over a week of shooting, not to mention 15 effects artists working for a year to make them “seamless”.

The most complex of these shots is the fiat multipla shot, in which the main characters are ambushed in a car.

VIDEO 2 : Run Multipla shot.

Reason why we didn’t shoot the shot greenscreen….

It’s vitally important to the realist nature of the film that nothing feels even slightly phoney, with the best lighting in the world, a complex and lengthy shot like this would have been an impossible challenge as a green screen. The subtle light changes and interaction, the burning car ambush, the motorbike stunt, the police cars arriving and the final moment when theo leaves the car, which seals the deal and sells the ‘gag’ completely would all have been in danger of compromising the shot if we shot on stage. Shooting on location using transitions provided us with ultimate believability. Based on story boards and a static read through we provided Alfonso with pre-viz, with colour coding to indicate a change of location.

VIDEO 3 : Run Previz

1. The rig

Now in dissecting the shot it’s important to start with the rig that was used.

This apparently continuous shot is made up of 6 separate pieces of photography.

The rig used to create this shot consists of the following:


A fiat multipla car with the roof removed.
A re-enforced body structure to support a cabin above the car
for 4 crew to direct and operate the camera.

Two engines. Two seats for 2 rig drivers one front and one rear.

The car cabin itself for the actors

The camera rig.

A retractable windscreen to allow the camera to move all the way out to shoot wide shots of car interior, and move back into place when the camera was shooting the other direction.


The car rig was then employed in 3 different locations to create the shot.


(talk though lineup)

Locations were chosen for their suitability for staging each particular piece of action. I.e. Ambush, long dialogue piece etc. Using just one location would not work for the entire shot.

The transitions in the shot enabled the various pieces of photography to be split over numerous days.

The camera rig was fixed at the same height to create a consistency throughout the six different pieces of photography.

Transitions were designed around the action using the window uprights as ‘joins’. Panning forward to the ambush, whip panning back with a bullet, the windscreen breaking, panning forward to see the approaching police and stepping out of the car were all events used to create transitions.

Each new piece of photography was cut with the last piece ‘live’ on the set to ensure the transitions were working. Ajdustments were made after each take to get the transitions spot-on.

A tracking vehicle with multiple cameras was used to shoot the same travel as the car rig; acquiring plates that helped with the compositing of the transitions.

A CG roof, CG windscreen, CG breaking windscreen, CG Motorbike and digital Stunt double, CG ping pong ball. Heads-Up display. Digital blood. Were all added to the shot.

VIDEO 5: Run Multipla shot breakdown.

Production reasons for transitions :

The shots all involve complex choreography involving actors/dialogue/stunts and background action.

So designing the shots in this way we were able to

Break up the shot into manageable chunks that fit into a shooting day. Enabling us to ‘bank’ a piece of shooting and move forward, the longer the piece you shoot the more prone to errors.


Give the director and the ADs more opportunities to get each piece right and build the shot in blocks and minimise the amount of resetting that had to be done if one of the elements missed it’s cue/mark.

It was also a way of saving money on set build. For the interior section of the refugee camp shot, the designer built 2 floors of the apartment block which with the use of digital transitions became 6 floors.

It also gave us the opportunity to use multiple locations for the shots as there was no one place that contained all of the necessary geographical features required.

For the multipla, there was no suitable section of road long enough and with the right attributes to contain all the dialogue and action. So it was split over three locations

The other shot that utilises multiple transitions is the battle of Bexhill sequence :


The trick here was designing transitions that wouldn’t be jarring or obvious, Alfonso didn’t want us to use the standard tricks of wiping frame with a large object that obscures or as he called it, the “waiter with a tray of drinks”, so we had to think of a device that would facilitate a natural transition.

The transition has a long history, dating back to Alfred hitchcocks “ROPE” in 1965 which was shot as a supposedly continuous “unedited” piece. In some ways this is the great grandfather of children of men. Unfortunately the technology didn’t exist to make seamless or sophisticated transitions, so they had to resort to unmotivated camera moves which kind of gave the game away :


Transitions have moved on since then but still tend to suffer from the waiter with the tray of drinks problem, so we had to design a device that wouldn’t give the gag away.

The inspiration for the spirit of these transitions for me was this beautiful shot in the film contact.


The idea we came up with was that Clive would stop at various points to see if his way ahead was clear, at this point the camera pans off of him and becomes his pov…and we see what he sees, he then ducks back into frame and the action continues. So every time the camera leaves clive we are doing a transition into a new days photography. The device was successful because of the wide framing, we the audience don’t really miss clive, and because there’s motivation for the camera panning off of him, it doesn’t feel like a cheat.



The exteriors for this shot are set builds at two different locations bushey hall and upper heyford and the interior is a green screen set at pinewoods ‘R’ stage. There are five transitions in all.

There’s also a hidden transition in the opening shot. Again it was necessary to divide the shooting into two days. We shot the interior piece on Saturday and the complex exterior piece on Sunday. Because we’d decicided on a practical explosion.

Shooting Fleet Street.

The shot starts inside a café and follows the lead protagonist out of the café door and down a very busy city street. It culminates in a huge explosion destroying the café he’d just walked out of…all in one handheld shot.


The way to acheive all of this in one shot was to shoot it in two pieces over two days.

Day 1 would be inside the café. Day 2 would be the exterior piece of the shot and the two pieces would joined by a digital transition.

It is an incredibly complex shot in terms of logistics and choreography. Utilising 300 extras, 20 stunts, a huge special effects explosion and 100 or so vehicles. Splitting the shot and using a transition enabled the AD’s and the Director to break the shot into two to give a greater chance of getting all the choreography correct and enabling the SFX team to rig the enormous practical explosion in the café. It also meant that the make up/prosthetics team could redress the actors in the café so they look wounded after the explosion.

The line-up was tested on set by linking the video assist output to final cut pro to create a live edit of each take. Adjustments in camera position and background action could be made after each take based on the live cut.

Stunt people on wire “jerk” rigs were shot separately and composited into the plate

HDRI reference photographs and surveying techniques were used to acquire environmental data from the location that would ultimately help create the futuristic moving billboards.

The final transition utilises passing traffic, the café door and the reflections in the café glass door to provide a ‘join’ without ‘wiping,’ and keeps the character in shot throughout through use of reflections.

Secrecy & magic

Nothing worse than listening to VFX people banging on about how they did things.

So I’m going to stop now.

Thank you.