Legend or truth: the VFX of Hercules

Brett Ratner’s Hercules tells the myth – and the truths – behind the demigod son of Zeus. Visual effects supervisor John Bruno had to walk the line between the man and the myth in both helping to craft the film’s gritty battle action and bringing to life the Hercules’ legendary Twelve Labors in which he encounters a series of fantastical beasts. Despite these daunting effects tasks, Bruno still saw a need to de-emphasize the effects and maintain realism. “The most fantastical effects were Hercules’ Labors,” says Bruno, “but we still wanted to base those on reality. Although the creatures became quite large we still wanted to set them up in an environment that was quite real.”

Aiding in achieve this goal were visual effects studios Double Negative, Prime Focus, Cinesite, Milk VFX, Method Studios and Utopia, with The Third Floor delivering previs. We take a look at just some of the main shots and sequences from the film, from the creation of the Nemeean lion to the vast Greek landscapes.

– Watch WIRED’s breakdown of Dneg’s creature fx from Hercules.

A lion encounter

The Nemean Lion.
The Nemean Lion.

In one of the first Twelve Labors depicted in the film, Hercules (Dwayne Johnson) stalks a Nemeean lion in a cave before a close-up fight. Designs for the 16 foot long lion were carried at Weta Workshop and also by concept artist Rob Bliss who also made ZBrush sculpts. “It had to be a combination of a sabre toothed cat and a lion,” says Bruno, “with an overly strong developed muscular system for the chest and the front legs.”

The Third Floor crafted previs for the fight based on storyboards developed by Bruno. “It was very moody and Brett wanted to keep Hercules’ face mostly concealed for a later reveal, notes previsualization supervisor Joshua Wassung. “So we did moody lighting and atmosphere with dust particles and God rays. It felt like an updated version of an old fashioned creature movie.”

Third Floor previs.
Third Floor previs.

This sequence was also one The Third Floor delivered in stereo. “One shot in particular where the lion leaps at Hercules was really fun,” says Wassung. “Hercules catches its jaw, one hand on the top and bottom – which was great fun to do in stereo – and we threw some saliva on the lens and showed Hercules being pushed back by the huge mass of the creature.”

Production designer Jean-Vincent Puzos built a cave set with stalactites and stalagmites “that looked, says Bruno, “like the teeth of an open-mouthed lion, especially in stereo.” Much of the fighting action involved Dwayne Johnson grappling with a stand-in blue 3D printed head piece based on Dneg’s lion model that was held by two grips.

Original plate.
Original plate.
Final shot.
Final shot.

For Double Negative, this was the first labor in the film that had to reveal the myths that had been spread about Hercules, and so dictated the style of creatures they had to create. “There’s mythical Hercules, the Hercules we know from legend and the Hercules they portray as a mercenary for the King,” says Dneg visual effects supervisor Ryan Cook, who shared duties with Paul Riddle. “The interesting part of the script is where you have the lion and the hydra and all the creature work, but then there’s the reality of what really happens.”

To craft the lion, artists began with Bliss’ ZBrush sculpt. “Whilst we were making a fantastical beast, I felt that the best approach was to try matching to a real lion, get a photoreal looking lion, and then allow us to be drawn into lookdev for what looked like a giant beast,” recounts CG supervisor Julian Fodd. “I went to a zoo and shot loads of reference of real lions, and that’s what we based the model sculpt and the texture paint on.”

Watch part of the lion sequence.

Dneg created a muscle mesh and a separate skin mesh for the lion, with animation done in Maya, overseen by animation supervisor Nathan McConnel. Then, Dneg’s in-house fur grooming tool – Furball – was used to deal with the several different layers of lion fur, from short clumps to the large mane before rendering in RenderMan. Furball is a GPU-based procedural system based on a Houdini-style node graph. “These graphs define a series of filters or operators to apply to our curves,” explains Dneg R&D lead Francesco Giordana, “starting from a set of guide curves and gradually adding more and more detail. Because every operation is perfectly self-contained inside a node, the groom artists had maximum flexibility in assembling those graphs and achieving really complex looks. Effects like wisps within wisps were relatively easy to achieve.”

The compositing team helped marry some set extensions to the cave set, and then integrate the lion. “The main thing we were having to interact with was probably in relation to the fur,” says 2D supervisor Robin Beard. “A lot of the contrasty light meant that the fur tended to look quite contrasty. It was almost like it was self-shadowing, so within the comp the guys were using like an un-occluded render to selectively mix that back in and almost give the fur some more detail.”

Interestingly, Dneg’s lion build took place while filming was still continuing. That way, explains visual effects producer Kate Phillips, an almost final version could be shown to the director during plate turnovers. “When Ryan and I went to LA to do turnover meetings we were able to take with us a selection of shots of the creatures, including the lion leaping,” says Phillips. “As soon as Brett saw it, he loved it, and it was a great help for us to get the clients on board with what we were doing – and getting their trust, and letting us complete the sequence in the way we could.”

Battling a boar

Dneg's CG boar.
Dneg’s CG boar.

Dneg’s creature work continued with another labor – that of Hercules dispatching a giant boar in a snow-covered forest. “I started designing something with Weta Workshop to be the size of a rhino,” says Bruno. “The direction was, what kind of creature you would find on King Kong Island – something a little bit too big or odd and the last of its kind. I had it big enough that it could rip up a field and Hercules would need to run up the tree to get a good shot at it.”

A feature of the sequence is the boar – a completely CG creation by Dneg – crashing through a tree in slow motion, causing bark splinters to fly towards camera. “That was an SFX pass that (special effects supervisor) Neil Corbould orchestrated which looked amazing,” explains Cook. “Ultimately, because they wanted it be even more slow motion we had to revert to doing that fully in CG.”

The boar up close.
The boar up close.

For the splintering shot, Dneg artists replicated a model of the tree with internal wood and external bark layers which was then fed into Houdini and subjected to shattering algorithms. “The first few passes just used Veroni noise but it didn’t look enough like splintering wood,” outlines Foddy, “so the team worked on a special shattering solver that gave lots of little spikes to simulate the fibers of the wood. That really helped the way it fell apart and the pieces snagging on each other. That was hidden behind a bark layer, with the sim an RBD layer that reveals the shards of wood coming out. There are secondary sims of particulate and fibers of wood which helped sell the whole thing.”

The CG boar was also shown interacting with mounds of snow. Says Foddy: “We used a solver we developed a few years ago for doing wet sand which has been adapted to work with settled snow – the Atom solver inside Houdini which is also GPU based so only takes seconds a frame.”

Breaking through the tree.
Breaking through the tree.

Compositing the boar into the forest proved challenging, but was aided by CG gobos placed on the boar to reflect dappled light. “The tree exploding and boar looked great coming out of CG,” says Beard. “We did some breath passes in effects and also out of NUKE just doing the snorting breath out of the nose. The biggest challenge was getting the snow to look right – we did a lot of deep compositing and trying to blend with the set dressed snow and do boar interaction.”

Hail Hydra

Watch part of the Hydra fight.

Another of Hercules’ labors is his swamp encounter with the Lernean Hydra in which he severs the many heads of the creature. The scene was shot in a 60 x 40 feet tank designed by Puzos. “Jean made trees out of root systems which were recycled from a different set,” explains Bruno. “He hosed them off and he basically used the roots, sprayed darker colors and then it looked like a strange, mythical swamp with a lot of depth and visual cues.”

Original plate.
Original plate.
Final shot.
Final shot.

That tank set was surrounded by bluescreen and later augmented by Double Negative with a CG environment and SpeedTree greenery. For the Hydra decapitations, Dneg developed a rigging approach that would give animators the ability to ‘slice’ the creature at any point Hercules’ sword went through its body. “Our creature supe made a rig that allowed the slice points to be slid around along the body,” explains Foddy. “It worked with a procedural system so the angle of the cut could be changed if we needed to. In the original first pass animation, everything was being cut at 90 degrees and we soon realized that that was going to look very samey. You’re now seeing different parts of the internal anatomy revealed depending on the cut.”

Original plate.
Original plate.
Final shot.
Final shot.

Dneg’s water sim solver – Dynamo – allowed for churning, splash, foam and spray and silt particulate passes, as well as small rivulets landing on the Hydra’s body. “One thing we hadn’t done before also was having the little plants floating in the water and the interaction with water and blood,” says Cook. “Sometimes we replaced the existing water in the plate, and we also did some digi-double replacements of Dwayne to show water running down his back or have CG digi-double spec passes over the top of the body for water interaction.”

The mysterious Cerberus and the three wolves

The Cerebrus.
The Cerebrus.

Hercules recalls the death of his family in a hallucination in which he sees a Cerberus amongst hundreds of dead bodies. Double Negative created the three-headed beast and inserted it into live action plates. “For that shot,” explains Foddy, “they dressed the set with hundreds of dummy bodies but there were a certain amount of real people lying down as well, but with no attempt at interaction or movement in the plates. Once the surface animation was finalled we did an additional pass of CG bodies.”

Ultimately, Hercules battles three wolves in a dungeon, picking them off one by one. To shoot the sequence, Bruno first had three stuntmen in green suits choreograph the fight with a stunt double. “We video’d it, showed Brett and he approved the angles,” says Bruno. “On the day we filmed there’s the wolf handler and the chains are going around the necks of three stuntmen in green suits who worked out the routine with Dwayne and his stunt double. Then the guys in the green suits get out of the way and everyone has to mime what just happened for a clean plate.”

The wolves.
The wolves.
Wolves up close.
Wolves up close.

In generating CG wolves, Dneg again relied on its Furball technology for realistic fur, especially since the wolves were continuously colliding with collars and Hercules’ hands during the fight. “We devised a multi-layered simulation system where we could first simulate the broad motion for the whole body and then selectively add more detail just in the areas where it was needed,” states Giordana. “This could be achieved by extracting data form the graph from multiple locations, representing different steps of the grooming process and different levels of detail, and then being able to plug it back in where needed with some clever interpolation techniques. The challenge was to arbitrarily reapply those simulated curves back at any point and transferring the motion without destroying the existing look.”

Simulating centaurs

Another creature-build required for the show was for the centaurs – at least in terms of a fantastical reference to them. In reality, the warlord Rhesus has managed to spread the myth that he has an army of centaurs whereas they are in fact just man and horse.

John Bruno shared in pre-planning for how initial shots of members of Rhesus’ army might ‘look’ like centaurs. “What would make you think that there’s a man and a horse as one unit?,” says Bruno. “What could do that? What visual trick could we use to actually see a centaur through staging? We did some digital tests of riders on horseback, backlit by the sun, and I looked at illustrations and paintings of centaurs.”

“What we came up with,” adds Bruno, “was a man’s torso and waist and hips joined up to look like it was a centaur. We also got smaller horses and riders to fold their legs back, and when backlit by the sun – when the horses head was lined up perfectly – it looked like a centaur. We got some in-camera but we also do have digital centaurs because there’s no other way to do them.”

Cotys’ courtyard citadel

Original plate.
Original plate.
Final shot.
Final shot.

A large chunk of the action takes place in Cotys’ courtyard citadel – a massive set designed by production designer Jean-Vincent Puzos at Origio Studios. “He built a football sized area,” outlines Bruno. “We had the King’s palace, entry gates, the surrounding village and a temple of Hera. There were six giant greenscreens that surrounded the temple walls which were anywhere from 30 to 60 feet and 100 feet long.”

The visual effects teams extended anything above the pillars and added in the mountains and landscape behind. Double Negative co-ordinated the approach to the builds. “We took a 3D procedural approach,” says Foddy, “where we built a kit of parts and kept moving pieces around. They all shared textures but had additional dirt maps that could be mixed up.”

Original plate.
Original plate.
Final shot.
Final shot.

For background mountains a two and a half D projection approach was taken. “I went to Croatia to a mountain location that we were trying to re-create and shot lots of photography,” recalls Foddy. “Ryan Cook then returned to that location with a helicopter shoot for aerial photography. We used that shoot to do a photomodel reconstruction of the mountain which became a proxy in NUKE for two and a half D projections.”

Athens adventures

The Acropolis helicopter shot.
The Acropolis helicopter shot.

Some flashback scenes provide views of Hercules with his family in Athens. For wide city shots, including around the Acropolis, Milk VFX worked with Double Negative to deliver digital environments and crowds. “We were part of designing multiple camera angles,” outlines Milk visual effects supervisor Nicolas Hernandez. “We had a master sim of terrain that we took from Google Maps. Once we locked down the main terrain, we had to design the rest.”

One of the more challenging aspects of that work was blending in with partial sets that had been built while also creating clean white marble surfaces for the buildings. “For that we used some procedural texturing methods,” says Hernandez. “We used procedural noise for dirt for things like little cavities. We also did a full CG render with lots of AOVs to help control the shininess of the final look and help with blending into the live action.”

A helicopter move around the Acropolis was one of Milk’s signature shots, and demonstrated the required mix of buildings, vegetation and crowds (which were done in Golaem). “We developed 50 different standalone buildings, and developed some tools to scatter buildings, props and vegetation,” states Hernandez. “There’s 10,000 trees. 15,000 houses. 1,200 stalls or markets. It was billions of polygons in total all rendered in Arnold.”

Milk's CG snakes and statue.
Milk’s CG snakes and statue.

An earlier flashback depicts a child Hercules killing off two snakes which had emerged from the eyes of a statue of Hera. Milk VFX completed visual effects for the shots. “They shot some real snakes – emerald tree boas – in live action which was great reference,” says Hernandez. “We developed an animation rig just for animation with no scales but controls for muscle contraction. Once the animation was done we went into a secondary fx rig for a lot of secondary fx on top of the animation by computing stretching and compression of the snake and also the friction. We also developed a tool to re-attach scales on top of the snake body.”

“Shader-wise,” adds Hernandez, “we used a lot of sub-surface scattering and we did some R&D to get an oily specular look on top of the scales. Also, the statue on set had to be completely replaced since it was made of papier-mâché and it had to look like marble.”

The Bessi battle

Watch some of the Bessi battle.

Hercules is hired to assassinate Rhesus by Lord Cotys, and sets about training an army. But they are engaged to fight hundreds of Bessi warriors prematurely and are almost totally slaughtered. Working with Double Negative, Prime Focus delivered shots for this battle involving CG crowds, digi-doubles and environments, overseen by visual effects supervisor Alex Pejic.

The battle was previs’d by The Third Floor. “The sequence is about building suspense – they’re walking into a trap,” notes The Third Floor’s Joshua Wassung. “Ultimately when the battle breaks out, Brett Ratner was really interested in finding a way to have each of the main characters have a unique thing to do and fighting style to show off their skills and abilities. There was a lot of exploring of that, seeing what Hercules could do to show off his strength and what Atalanta could do to show off her skills as a archer.”

Bessi previs by The Third Floor.
Bessi previs by The Third Floor.

Prime Focus relied on Massive for the crowd work, starting with mocap filmed at Shepparton Studios. “We cleaned that up in Motion Builder and then our animation team would do the animation,” says Pejic. “Then we used a custom built procedural shader from Massive to Arnold to render the shots. We had other tools too to do visualization in Maya and give full control over the Massive agents in the scene.”

“In one fully CG shot that’s an aerial shot,” continues Pejic, “Third Floor had done the previs and then we took it over to re-build the whole environment, re-creating everything that was on set to the smallest level of detail – the village, trees and fire. The ground is very dusty so we did a lot of effects for that too.”

Revolt against Rhesus

Hercules takes on Rhesus’ army.

With a more well-prepared army, Hercules now takes on Rhesus and his soldiers – who have long been thought to include centaurs. The battle was filmed on location in Hungary, with Cinesite creating environments and crowds for the sequence under visual effects supervisor Simon Stanley-Clamp.

“The brief was always to make the live-action bigger,” says Stanley-Clamp, “by adding armor and horses and the army and fleshing out the location with the specific landmarks. That was done with a combo of matte painting, 3D projection and modeling and SpeedTree builds.”

Original plate.
Original plate.
Final shot.
Final shot.

For the battle shots Cinesite crafted digi-doubles, digital horses, fur, cloth and hair sims. Crowds were realized with Golaem. The studio used models from Dneg and Prime Focus and adapted textures to its own pipeline. “We also did three days of motion capture at Centroid based on early versions of the cut,” recalls Stanley-Clamp. “This involved soldiers marching, throwing arrows, little set pieces where they divide apart, swordsmanship, falling over, being shot and falling to the ground.”

“Centroid have a lovely piece of software which allows you to look at the video takes, pop in time codes and it automatically selects the data,” adds Stanley-Clamp. “They process it and they turn it around very quickly. We made further selects on the mocap data and our team of animators would plug that data into the re-rigged models. Then our rigging department had to tweak intersections and the models – then integrate into Golaem. Our biggest shot has 10,000 soldiers with horses with most at around 2,000 to 3,000 soldiers.”

Original plate.
Original plate.
Final shot.
Final shot.

Stanley-Clamp says that having a fair amount of camera movement helped sell the shots. “There’s a series of shots in there coined ‘The Avengers’ shots because it was filmed as one continuous take with lots of overlapping action. It was chopped down to four shots but I think they’re very successful because you’ve got foreground, principal action, mid ground CG and matte painting and set extension which allows for lots of depth cueing and so it feels pretty epic.”

Cornering Cotys

Watch Method’s breakdowns.

The film climaxes in a revolt by Hercules and his crew against Cotys, who turns Thracian soldiers on the mercenaries. In the ensuing battle, torch cauldrons are overturned to start large fires and a large statue of Hera is also downed causing destruction amongst the temple – with shots previs’d by The Third Floor and effects created by Method Studios overseen by visual effects supervisors Doug Bloom and Nordin Rahhali.

Third Floor previs.
Third Floor previs.

The sequence was filmed mostly at night which meant black skies had to be replaced with sunset views, a significant effort from Method in terms of roto and paint work. “Along with that there’s all the oil spilled and running down the stairs, and it’s actually on fire,’ says Bloom. “It had heavy effects simulations and volumetric rendering as well as some additional hero digital doubles where we’re replacing soldiers in the fire and who catch on fire.”

Original plate.
Original plate.
Final shot.
Final shot.

The crescendo moment is the large scale destruction of the Paris statue in the temple. As that’s destroyed, a significant portion of the temple is also destroyed. “The first thing we focused on was a pacing exercise in blocking all of our shots and working with John Bruno and the client side team,” notes Bloom. “Then we ran one long simulation for the destruction and in that sim our model was just chopped up by our modeling department and had very simple breaking the environment up to clean edge sections – it almost looked like a wooden play set for a kid.”

Fracturing, RBD, additional volumetrics for dust and particulates for sand and pebbles in Houdini and complicated compositing done in NUKE made up the final shots.

Original plate.
Original plate.
Final shot.
Final shot.

“It was a 14 or 17 second long sim that showed the entire event to where it’s completely crumbled,” adds Bloom. “We looked at the camera angles blocked out in the previs and then we started placing the cameras in environments and slipping that sim to find some key moments of destruction. When we got that worked out, we passed that out as reference to our effects artists, who started working with higher res geometry so they had more interesting shapes and internal structure and details.”

All images © 2014 Paramount Pictures and Metro-Goldwyn-Mayer Pictures. All Rights Reserved.

7 thoughts on “Legend or truth: the VFX of <em>Hercules</em>”

  1. Pingback: Legend or truth: the VFX of Hercules | Occupy VFX!

  2. So many of these fx should have been done practically. Like destruction / debris stuff. Sad to see that almost everything are created digitally these days…

  3. Pingback: Legend or truth: the VFX of Hercules | fxguide | Occupy VFX!

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  5. Pingback: Dane | art and design

  6. Pingback: Fighting For The Lion’s Share « Pixologic: ZBrush Blog

  7. Pingback: Hercules Shots I contributed to in articles around the web « LucaVFX

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