Top blockbuster VFX you're not meant to see

Plenty of summer blockbusters and event television shows are of the effects-driven variety, filled with incredible computer-generated characters that still retain a sense of photorealism.

But in recent times, more and more films and television series are featuring effects of a different kind – invisible ones. They are the effects you might not always notice, although sometimes they involve just as much effort to ensure they remain unseen. Invisible effects can be used to place characters on a fast-moving train, to seamlessly replace the facades of old famous buildings, or even to make a Hollywood star skate on ice. 

In fact, these were just some of the tasks given to studios Cinesite, Eight VFX, Union VFX, Rodeo FX and Framestore as they delivered invisible effects work for The Commuter; I, Tonya; Three Billboards Outside Ebbing, Missouri; The Greatest Showman and Darkest Hour. Here we explore how a whole wave of impressive seamless effects made it into those films.

01. Liam Neeson on a train in The Commuter

Liam Neeson jumps between train carriages

Liam Neeson’s character in The commuter leaps between carriages. The action was filmed on a bluescreen partial carriage set at Pinewood studios on a raised 15-metre platform. Cinesite then added in a digital train and moving background environment

While director Jaume Collet-Serra’s train-ride thriller The Commuter starring Liam Neeson includes its fair share of carriage crashes and explosions, the film also contains a surprisingly high number of invisible effects shots involving digital trains, set extensions, plate stitches and exterior environments.

That work was overseen by production visual effects supervisor Steve Begg, with Cinesite delivering 860 shots as lead vendor. A large portion of these shots were exterior composites of the environment the train is travelling in, often seen through the windows of the carriage.

Neeson and fellow actors were filmed on a bluescreen train set on a hydraulic rig to provide movement, while a massive effort was required to acquire environment reference and then to rebuild that digitally.

“To create these environments and help us plan the visual route, Steve Begg and his team went in and around New York and filmed 360-degree elements from the back of a truck, as well as from trains and a helicopter,” outlines Cinesite visual effects supervisor Stephane Paris.

“Whenever we see the exterior of the moving train in this section of the movie it is CG, as well as the environment it’s travelling in, apart from a few shots filmed from a helicopter. The daylight environment shots of the train formed the main body of our work – approximately 400 shots!”

Shot of Liam Neeson in a train

Even a seemingly standard shot in The Commuter, looking from outside the train to the interior, involved a digital version of the carriages and environment

At one point, Neeson’s character becomes embroiled in a fight against his adversaries. It is played out in a single long shot that was actually 14 different takes stitched together. “An effort was made by the crew to line up subsequent shots to match the positions of the actors and camera in previous shots,” explains Paris. 

“However, the perspective of the carriage, camera zooms and background deformation were often not smooth and it was necessary to re-project the carriage interior onto geometry to give more camera control for the multiple required transitions.”

Some of the weapons seen in the fight, including a guitar and an axe, were CG, as were smashed glass and window elements. This was in addition to the digital exterior environment and even portions of the train.

“Also,” notes Paris, “digital versions of the characters fighting were created to aid the transitions between the plates, as well as the environments and train infrastructure in many instances, so that the camera could move freely through the action and the divisions between the carriages. The stunt actors’ faces were replaced with the actors in several, more physically demanding shots.”

02. Face replacement in I, Tonya

Margot Robbie in a facial capture scan

For I, Tonya, Margot Robbie underwent a facial capture scan so that Eight VFX could perform face replacement for parts of the ice skating scenes

I, Tonya, directed by Craig Gillespie, also employed face replacement, which was crucial to telling the true story of the notorious Olympic figure skater Tonya Harding (Margot Robbie) implicated in the ‘hit’ against rival Nancy Kerrigan. First, there would need to be some extensive skating scenes with Robbie, who is not a professional ice skater, portraying Harding on the ice and pulling off her classic triple axel move. 

That’s where Eight VFX came in. Their methodology was to employ a seamless face replacement approach for Robbie, and then also fill out arenas with crowd extensions.

“Margot actually did five months of skating training and was able to do a huge amount of the skating herself,” says Eight VFX visual effects producer Juliet Tierney, who worked with visual effects supervisor Jean-Marc Demmer on the film.

“For the more complex parts of the routines and jumps, there were skating doubles who were filmed with tracking markers on their face and head. For some shots, after the double had skated, a bluescreen area was set up near the rink so that we could film Margot’s facial expressions for those tricks. For other shots, where no bluescreen takes were available or the skating was too fast, full CG face replacement was used.”

Scans of Margot Robbie's face

The resulting facial capture scans and digital models

This involved facial capture using a photogrammetry rig supplied by EISKO. Robbie was captured with four different make-up looks. Once the data was processed, it provided Eight VFX with both facial geometry and textures. This was then brought into Maya for animators to rig and hand animate Margot’s facial expressions.

Careful editing also meant that shots transitioned from Robbie starting and ending a routine while stunt performers and the face replacement was used for different parts of the scenes. Still, face replacement was only half the challenge. Harding’s routines take place in different locations, including at the 1994 Winter Olympics in Lillehammer, Norway.

Eight VFX had the rinks used for the shooting scanned, and then recreated them in CG. That way they could be populated with digital crowds and signage for the final sequences. Tierney is particularly proud of one three-minute shot that was created from three different shots.

“The first and last shots have Margot skating, and the middle shot has face replacement. Because this is one final shot the middle plate had to be perfect so you can’t feel the difference between the real Margot and her CG double. We also rebuilt the stadium in CG, added CG crowd for the audience and gave the sequence its own look with anamorphic lens flares.”

03. Fawns and flames in Three Billboards Outside Ebbing, Missouri

Frances McDormand looking at a fawn

A simple but subtle moment in Three Billboards outside Ebbing, Missouri involved the compositing of a fawn against bluescreen into a plate with Frances McDormand

Best Picture Oscar nominee, Three Billboards Outside Ebbing, Missouri, is director Martin McDonagh’s tale about a woman who, after her daughter is murdered and no culprit is found, calls out the police for inaction via three large advertising signs near her town.

The small film still required some invisible visual effects work by Union VFX, including for when Mildred (played by Frances McDormand), encounters a fawn, and as opponents to her signs try to burn them down.

A tender moment occurs as Mildred is tending to some flowers at the billboards and sees a fawn nearby. McDormand and the fawn were shot separately, with Union compositing the two elements together.

“The trickiest thing was the fawn,” outlines Union visual effects supervisor Simon Hughes, “because basically we had to go to a different location where the animal trainers had deer and we had to set up a bluescreen there. And then we had to wait around for the right kind of lighting direction and for the deer to do things.”

Frances McDormand looking at a burning billboard

To heighten the sense of danger from billboard fires, Union VFX added both real and digital fire elements to these final shots

A more complicated sequence has Mildred and her son trying to extinguish the billboards after they have been set on fire. Here, a combination of practical fire elements and digital fire made the shots possible. “Frances stood in position and we had some lighting rigs out of frame for interactive lighting,” says Hughes.

“We also manage to actually squeeze a little bit of fire towards the edge of frame away from her. But then we also took Frances out and did an element shoot matching that camera position, setting the actual billboard on fire using flame bars and some paraffin on the face of the billboard. For the interaction with the fire extinguisher we resorted to CG fire, which we did in Houdini, and some smoke to come from the extinguisher.”

04. Not-so-showy VFX in The Greatest Showman

Building on fire

Seamless digital extensions of live-action photography are a mainstay of invisible effects work, including for this fiery scene from The Greatest Showman

Several VFX vendors contributed shots to Michael Gracey’s debut feature, The Greatest Showman, which tells the story of P.T. Barnum and his founding of the Ringling Bros and Barnum & Bailey Circus.

Production visual effects supervisor Mark O. Forker oversaw these studios, including Rodeo FX, which took on sequences involving a mix of fantastical cityscapes and scenes that required placing characters in sets that didn’t exist, and even burning down P.T. Barnum’s theatre.

As part of his stylistic approach to the film, Gracey decided to partly realise the cityscapes with miniatures. Rodeo then augmented the shots with painterly skies. “All the miniatures were built in 3D in the proper scale and then 3D printed,” states Rodeo visual effects supervisor Martin Lipmann.

“We placed them on a huge table that was lit from underneath; as live footage was going to be added to these shots, everything had to be to scale. We shot this sequence with a 30-foot Technodolly. We reprogrammed the moves from the previs on set. With the repetitive movement we were able to create different lighting scenarios, from dark to light to moonlight and sun.”

The burning Barnum theatre used a number of invisible effects tricks. A mix of custom practical fire on gas pipes matching the right window measurements served as elements. The strength of the flames on the pipes was controlled to re-create the progression of fire through the sequence.

“We also used CG fire for the lighting interaction with the CG extension of the building, and CG ashes and embers to connect all the shots together,” says Lipmann. “The collapse of the building was done in Houdini and comp’d in Nuke.”

05: The portrayal of war in Darkest Hour

Ariel view of a bombing run

This God’s-eye view – all cG – of a bombing run in Darkest Hour is part of a long shot that ultimately ends on the face of a dead soldier

In Darkest Hour, Joe Wright’s account of Winston Churchill’s (Gary Oldman) time during the early days of World War II, visual effects had a sparse, but again, crucial role in the storytelling process.

The filmmakers, which included VFX studio Framestore, looked closely to 1940s archive imagery as reference for shots of buildings of the day, as well as a number of classic war-time scenes.

But this wasn’t a film full of massive battle scenes. One initial challenge for Framestore was adding dirt to period buildings. “We Lidar-scanned all of the main buildings, including Downing Street and The Treasury, as it was the only way to get a very precise template,” explains Framestore visual effects supervisor Stephane Naze. 

“Then we built a proper CG model and applied textures on it. The tricky part was to film everything in camera without any bluescreen – it meant a lot of work in roto for all the characters and extras to be able to modify the buildings in the background.” 

It took three weeks to render the shot with more than 50 per cent of the machines allocated for this film – no room for mistakes!

Stephane Naze

The studio’s other main challenge came from battlefield shots, mainly aerials showcasing carpet bombing with banks of explosions. The timing of these was locked in 2D to provide quick iterations, with the assembly of all the elements finished in CG. Naze says the toughest shot to achieve was a scene on the French battlefield, which finishes on the face of a soldier.

“Everything is CG until you finish the camera movement on the dead soldier. The goal was to get a very transparent transition and not be disconnected by this dramatic moment in the story."

"Also technically, the shot was very challenging by the nature of the effect – big explosions, flames, fire, a lot of research to be accurate. It took three weeks to render the shot with more than 50 per cent of the machines allocated for this film – no room for mistakes!”

This article was originally published in issue 235 of 3D World, the world's best-selling magazine for CG artists. Buy issue 235 here or subscribe here.

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