To help portray the appropriate freezing conditions of an Antarctic research base in Matthijs van Heijningen’s The Thing, With A Twist Studio contributed over 120 breath additions. We talk to visual effects supervisor David Burton and compositing supervisor John Bowers about the work.
fxg: Can you give me an overview of With A Twist’s work for The Thing?
John Bowers: We added cold-air breath to over 120 shots that were filmed on stage, and re-timed a handful of shots to achieve variable slow-motion effects. Some of our breath work involved compositing elements over the plate as shot, while in other cases we would pick up a finished composite and incorporate our breath into that.
David Burton: We had done a few shots back on Twilight and had known VFX producer Petra Holtorf from that show. We had also just finished up some shots on Fast Five, which was also through Universal so the stars kinda lined up, and we were fortunate enough to get on the show towards the end. What started as two shots went to 66 and then to 122. That’s pretty typical for us and reflects the reputation our artists have earned show after show.
– Above: Watch With A Twist’s breath reel from The Thing.
fxg: For the breath shots, were real breath elements filmed? How was this carried out?
Bowers: As part of the effort to match the look and feel of the 1982 film as much as possible, no digital breath was used on this show. Instead, practical breath elements were filmed on the same stock used to film the rest of the movie: an actor stood against a black screen, wearing a black face mask that left his mouth and nostrils exposed, breathing at various speeds and speaking syllables of varying shape and duration. A great deal of care went into selecting the best elements to use in each shot. Each take had its own considerations of ambient wind, mouth shape, length of breath, and orientation of the cloud with respect to the source and the camera.
Burton: Although our time was tight – three weeks – it was well worth the effort in the first couple of days to create a library breath elements broken down by direction, intensity, phonic, etc. We had artists from both the Los Angeles and Michigan offices working on this show. Shotgun was not only used to track and schedule the artists, but also the library of elements. Breath work is tough. It greatly contributes to the performance. Most of the time it’s subtle. You can’t judge it as a still image, you have to see it flow and listen the spoken words to insure you are adding to the performance rather than taking the audience out of the picture. Nerking breath work frame by frame always results in something that looks too heavy handed. Most of our crew has roots from the midwest and the north so we know how cold-air breath looks, and how it dissipates.
fxg: What approach did you take to compositing the breath and matching to the live action plate?
Bowers: The breath elements being shot over black enabled our compositors to color them in a somewhat predictable way: divide by a luminance key, play with the tint and brightness of the element, then premultiply by the same luminance key before layering the breath faintly over the plate. For one long scene in which our heroes are standing around a flickering fire at night, we decided to add a subtle touch to match that flicker. One of our compositors built a Nuke gizmo that – when we fed in a one-point track – would measure the color value at each frame in a small area on the face of one of the actors. After normalizing the result, we could then use that data to incorporate any amount of matching flicker that was desired: we could exaggerate it or dampen it down as the needs of the shot dictated.
Burton: Matthjis wanted to be very faithful to the 1982 version. That included details down to the breath. We went back and studied the 1982 version and used that as a guide especially for the outdoor shots. We picked out four or five shots to use as our hero versions to match to. For many shots we relied on 3D matchmoving vs 2D to make sure the breath would move with the performer without looking like a ‘card stuck on a face’. We have some neat tricks to get the feeling of depth from our work on stereo shows that came in handy.
fxg: What were some of the considerations between matching exactly the words spoken versus what looked most convincing?
Bowers: When you speak or breathe in a cold environment, there’s always a little delay before the condensation cloud forms – and it forms a few inches away from your face. We would always begin by matching the timing, position, orientation and scale of the element to the mouth of the actor in the shot, then would customize those things to achieve the desired impact. In a slow, dramatic scene where the intent is to build tension, for instance, we might actually slow down the element and allow it to linger in the air a bit longer than it really would. To add forceful impact to a character’s words, we might enlarge a few breath puffs and keep them closer to the person’s face.
Burton: Performance is reality. Breath can either come from the mouth or the nose. There are different movements and timing between the two. Often we used the nostril flaring as a guide to how heavy nose breath is. Mouth breathing is usually cued off the shoulders, or sometimes the ligaments in ones neck. Working with those subtle cues drives the reality of the performance. We often also played with the density the breath to help sell or heighten an emotion. In the end it’s about Matthjis’s vision so we start with reality and end with a powerful performance.
fxg: Can you discuss the slow motion shots – the fire time-ramps? What are some of the challenges of those shots in terms of maintaining the right look for the fire?
Bowers: One of the most challenging things with any re-timing is maintaining those areas at the edges of objects where interpolation breaks down. This is especially true of fire, which moves quite erratically and effects the illumination of objects in ways that any software would have a hard time compensating for. Executing a time-ramp for a shot that involves fire, then, starts off with the compositor experimenting with all the different parameters available (varying sample size, interpolation algorithms, vector smoothing, etc.) then blending together the best results from various methods. Once these tools have been exhausted, though, it boils down to good old-fashioned elbow grease: tracking in patches and hand-painting out single-frame artifacts until the effect is seamless.
Burton: Re-timing fire is a bitch. It takes math skills and tenacity. Keeping versions within double digits is the goal!
Images and clips copyright © 2011 Universal Pictures. Courtesy of With A Twist Studio.