Although ‘Kick-Ass’ is fast-paced and stylish, its visual effects rely mainly on 2D techniques - with interesting exceptions. It was an approach that Director and co-scriptwriter Matthew Vaugan and VFX Supervisor Mattias Lindahl agreed on from the start to stay true to the story’s origins as a graphic novel.
Based on the graphic novels by Mark Millar and John Romita Jr, the script is written by Matthew Vaughn and Jane Goldman, who also wrote ‘Stardust’. After working on the visual effects for ‘Stardust’, the team at Double Negative was familiar with the director’s working style. Mattias Lindahl served as the film’s overall Visual Effects Supervisor, with 2D Supervisor Peter Jopling and CG Supervisor Stuart Farley.
The brief for Kick-Ass was to maintain a gritty, realistic look and feel, without straying into fantasy. Mattias explained that the aim was to capture as much in camera as possible, “Since the story is set firmly in the ‘real world’, it was important to Matthew Vaughn that the visual effects never took front seat. For this reason I made an early decision to base as many of the effects as possible on real shot elements or backgrounds. If you shoot something for real, even if it’s just one element, then it will always look a lot better to the viewer, simply because it is real.
A projected matte painting was used for the sky and additional elements like cars and road furniture were all composited together with the hero’s green screen stuntman.
For this, the green screen performance was re-timed, CG buildings placed in the background and the crowds were also shot on green screen to avoid any accidents with glass on impact. “The falling green screen character was a blend of many takes to create the action, comped over a live action, special effects taxi. The building in the background was fully CG right down to the ground floor where we blended it back into the plate,” said Stuart.
Double Negative also set up the look development for the views from the glamorous penthouse apartment of gangster character Frank D’Amico, which were eventually outsourced to LipSync to match to when the shot count for these sequences began to rise.
Lining Up the View
LipSync rendered out the correct view via Maya and RenderMan. Tom Collier, LipSync’s VFX Supervisor said, “We would de-lens the green screen plate and line up the camera in Maya using the CG model of the apartment and the appropriate cyclorama to ensure we had the correct view out of the appropriate window for the correct time of day. A still - or a rendered camera tracked sequence if the camera was moving - would be rendered in Renderman and passed on to the compositor, who adapted and augmented them, scene-by-scene, to add more movement.”
Understanding how Matthew works through their experience with him was another positive factor. “Being able to quickly identify what he likes and doesn’t like enabled us to work through the shots more quickly and to be adaptable to any changes at the last minute. He likes his effects to be as real as possible, so if something works and he believes it, he doesn’t dwell on it or overwork the shot,” Tom said. “He is very open to the VFX crew suggesting new approaches to an effect to make it work. You can show him ideas, get an appropriate response and make progress on the look and style of a sequence.”
On set, the team had captured the interior of the penthouse set in detail using Lidar VFX, which helped when adding the destruction after the massive gunfight that takes place there toward the end of the movie. With this extensive modelling, texturing and look development completed on the building, the team could then add the building into the helicopter establishing shots filmed in New York. Farley said, “Working like this gave Matthew the ability to pick exactly the architecture that he wanted to suit his vision of Frank D'Amico’s apartment and set it against the exact backdrop of New York that he wanted, while retaining full realism.”
The climactic gunfight at Frank’s apartment was a very complex sequence that starts in the middle of the night when Mindy arrives in the lobby and ends just before dawn. Consequently, the lighting changed for every set up to track the passage of time. “We needed a lot of planning to pull this off. When we took our stills of New York, we had to take them at different times of the day to accommodate the passage of time,” Matthias said. “It all takes place in that ‘magic hour’. If you are ever standing on a rooftop at that time of night, you can see how the lighting changes so quickly. It’s a magical time.”
The team started by searching for reference footage of people flying with jet packs - and was surprised by the results. “They just didn’t look real at all,” said Jopling. “They all looked fake! It looked really stiff and unnatural and you don’t see flames or smoke. So we thought, this kind of detail is mostly in people's imaginations. This is going to have to be about what the audience expects to see.”
The new camera moves were then used to drive a motion control rig, based on a standard 35mm film camera, used to shoot the live action of Kick Ass and Hit Girl flying on green screen. However, the team knew the helicopter would be travelling faster than the motion control rig could travel and for a greater distance than could be handled on a sound stage. Using the tracked helicopter plates and several Double Negative proprietary 'aim cam' tools, they designed motion control moves that mimicked the perspective changes.
Once the actors were shot against green screen, they were placed over the New York plates to check that the scale and movements worked as planned while on-set, so that an additional take could be planned and shot if necessary. The occasional additional movement was added to help sell the idea that the characters were being pushed up by the jetpack and not simply hanging from wires.
For this reason it was vital that the additional CG FX jetpack flames and smoke sat into the plate realistically. The team concentrated on how a jet pack flame would register photographically. The actors were extracted from the green screen and CG flame, smoke and distortion were all added to the jetpack to give it a sense of power and energy. All the elements had been shot with motion-control as well, and the move was extended slightly in post. The jetpack effects were created in Maya with an in house fluid solver 'Squirt', and rendered in Renderman. All these elements were then composited in Shake.
“We had to animate Hit-Girl’s double bladed sword stabbing through Rasul and remove wires. We added blades, lots of spraying blood, a video game to the TV and scenery outside the green screen window,” said Anton Yri, VFX Supervisor. After the carnage in the apartment, Kick-Ass follows Hit-Girl to the rooftop, where he first encounters Big Daddy. This was shot on a sound stage surrounded by green screen. Similar to LipSync’s work on the Manhattan apartment, they were provided with a 3D model of the set and a panoramic matte painting of New York's skyline.
In another sequence, they needed to turn Frank D’Amico’s lumber warehouse into a raging inferno filled with roaring fire, massive explosions, choking smoke and other debris. “Mattias provided us with a huge library of fantastic fire, smoke, explosion elements that he had filmed. So we went a completely 2D route with this sequence, layering in dozens, sometimes over 100 fire elements in the wider shots, to get the level of danger and intensity Matthew Vaughn was after. Generally, the comment was always, 'More fire! More explosions! More danger!'
Night Vision Goggles
‘Kick-Ass’ is the story of an oddly charismatic New York teenager and comic book fan Dave Lizewski who decides to try his hand at vigilante justice, superhero style. Once disguised in his livid green suit he calls himself Kick-Ass and takes on the local underworld. Completely without superhuman powers, of course, he gets repeatedly beaten black and blue, but somehow inspires a groundswell of fans across the city.
His luck changes when he encounters a ruthless father-and-daughter duo of fellow crime fighters, 11-year-old Hit-Girl and Big Daddy, and meets another would-be superhero Red Mist – with thrilling results.
The Kick-Ass character and story maintains its graphic novel origins throughout the film. A key sequence that reinforces this link is composed of a series of 3-dimensional moves through the comic book world of John Romita Jr. Artists at VFX and 3D animation studio, Fido, in Stockholm handled the sequence.
A 2.5D technique was used throughout to realize this sequence. “From the start, the goal behind it was to be able to stop the sequence on any frame and it should look like a frame from the graphic novel. So it became apparent early on that we had to work together with John Romita Jr and his team,” said Mattias Lindahl, who also works at Fido.
“John created a set of storyboards based on the lines from the script. We then took the boards and created an animated previs. A lot of work went in to the storytelling and the use of 3 dimensional moves through the comic book world. When the previs had been approved by Matthew Vaughn I flew over to see John in New York. Final tweaks where done to the compositions of each frame together with John.
“Once John’s team had finished the artwork, the Fido team tweaked the geometry around to fit John's drawings. The artwork was then projected on to the 3D geometry to allow us to travel around it in 3D space. The software used was Maya, Photoshop and RenderMan, and it was all comped in Nuke.
Mattias said that Fido doesn’t have a specialty in the comic book style – other than reading lots of them! - but traditionally works with photorealistic creatures. “It was a nice change and a great challenge for the team to work on this sequence. This has never really been done before and the sequence was originally what got me really excited about working on the film. The whole piece really pays homage to John Romita Jr and we had to make sure at all times to keep true to his fantastic artwork.”
LipSync handled the green screen driving sequences, making sure that the exteriors blended with the foreground interiors. This required extensive retiming, smoothing and stabilising of plates to match the movements of the car, adding reflections in the windows and correcting lighting for the car interiors, using Shake and the Furnace plug-ins. Tom believes the key to good driving scenes is good green screens and lighting. “In one of these sequences, the team also needed to match footage from the original shoot with material that was reshot six months later. There was some different lighting within the shots that had to matted, keyed and graded out to ensure absolute continuity with the shots around it.”
A complex rather nasty scene saw the team composite an unfortunate character into a car, from several angles, as it gets crushed in a car-crusher. “As we would always recommend,” Tom said, “live action plates were used of the man in the car, which were static, and we applied movement and warping in comp to match this plate into the live action plate of the car being crushed – absolutely no 3D/CG was utilised.”
Words: Adriene Hurst