• CGSociety :: Production Focus

    23 April 2012, by Paul Hellard



    MPC talks about the team delivering 280 shots for the Wrath of the Titans movie. The main areas of work included; the opening Dream Sequence, the Chimera attack, the final battle with Kronos, the Makhai warriors and Pegasus, as well as the Gods dying and dissolving, full CG temples, set extensions and a number of stunning digital matte paintings throughout.

    Kronos

    Anders Langlands, MPC’s CG Supervisor says the team had been working since around October 2010 on the many aspects of Wrath, with Nick Davis, who’d worked on the Clash of the Titans. He talked to his crew about Kronos, the fearsome King of the Titans and Father of Zeus, Hades and Poseidon, straight up. For the initial conception stage of creating Kronos, the brief at first was quite open, allowing the great art department at MPC, headed up by Virginie Bourdin to go back and explore Kronos within Greek mythology. The brief was essentially a ‘walking volcano’, a constantly shifting mass of lava and smoke, with very little form to it, showing it to be a bit more abstract. But Nick Davis and director Jonathan Liebesman needed him to be relatable to his son Zeus and Hades. He ended up solidifying into a more recognisable character, pushing the sculpt in ZBrush to decide what he would look like in 3D. There were many iterations and versions of his appearance until a concept was settled on and the modeling department settled down to make the guy. “We tried to keep that idea that there was a constantly moving molten lava layer shifting underneath his skin,” explains Langlands. “Then on top of that would be these black plates of rocks like tectonic plates shifting around on the earth.”

     



    In order to get the look for that, the MPC crew covered one of their texture artists in clay, and let it dry. “We actually blasted him with hair dryers for an hour,” quips Anders. “The texture artist in question was photographed in great detail to study how the clay cracked and moved on his body. So we could actually use real reference of how the clay cracked and behaved at different angles as it became displaced.”

    The crew took B&W crack maps and started directing those onto the surface in ZBrush to see where the stretch and deforming areas were going to be, and that study became the final model for displacement.

     



    The teaser for the appearance of the Kronos was the Dream Sequence early on in the film where at the end, the gigantic wave of hot lava is thrust toward the camera. “We wanted to introduce Kronos as being the bad guy, but not show too much and give it all away,” explains Langlands.

    There are layers and layers of smoke and dust while Kronos is shown dealing with the crowds of soldiers. Beautiful matte paintings are (somewhere) in the background as well as dry ice drifts comped into the shots as well to create the quite ethereal sense to the dream sequence. “The rule is when you are trying to create something to appear that big, you tend to end up layering up so much stuff. The story is that he is devastating the human army just by lifting his hand up, and everything around this is simulated,” he said. “All of this generated a massive amount of geometry as you can imagine, which took an eon to render, but it looks fantastic!”

    Through exploring Kronos through a series of images, various avenues were investigated, from a more elemental creature through to a more human-like giant. Ultimately it was decided that Kronos should have a more human form to help reiterate the connection between him and his sons rather just being seen as a monstrous titan. The Concept art team then expanded on some of their original ideas of using volcanic rock as a base, as it relates to how something could develop and grow over time, and Kronos evolved from there.

    Once the direction had been decided, a texture reference was then created and used as a base for the 3D modelling and texturing pipeline, which could then be used as a point of reference for rest of the team. A variety of clay mixtures were created and painted onto the face and body of an actor which were then used as a reference point by MPC's modeling team to understand how magma and volcanic rock might move and fall around a moving object. The textures were also used for creating believable crack and displacement maps.

     

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    Chimera

    “Framestore had done a lot of concepts for the Chimera, and we’d had an early look at what the creature would be like,” explains Langlands. “A mix of a lion and a goat with a snake for a tail, massive wings and breathing fire all over the place, and we had to take that indoors to turn it into a living, breathing creature.” Modeling the hair was the most astonishing groom ever done on a mystical creature at MPC. Referencing oxen, bison, even donkeys, all to get the different furs into the model look development. “David Mayhew, head of our grooming department, did an amazing job,” adds Langlands.

     



    It was apparent that the Chimera creature would be too large and agile for a man in a suit to enact; so the decision was taken to develop it in CG, requiring a number of shots to be pre-vised giving the crew a geographical layout for the sequence. This informed the production designer’s decision to create arenas where battles could take place with the actors, stuntmen and props going head to head in precisely mapped out spaces. The Chimera itself was largely designed in pre production with concepts then passed to MPC who recreated the designs as a CG model. The specific challenge for MPC’s rigging and animation teams was how to make a beast with two heads move in a realistic fashion. MPC VFX Supervisor Gary Brozenich explains. “The trickiest issues involved where to place the split in the neck, how far back on his spine would feel natural and how to proportion the rest of the anatomy to compensate for this. We also had to gracefully handle the interpenetration issues arising from two heavily mobile portions occupying the same anatomical space. Thankfully, both issues were dealt with very effectively and very early on with range of motion studies.” MPC’s animation team looked carefully at the animation of the Chimera, referencing material of lions hunting and attacking. The Chimera’s breath vapor and fire so the FX team used a mixture of elements created using Maya and Flowline combined with actual flame thrower materials hot on set.
     

    Makhai

    The Makhai are two-headed, double-torso'd, sword-wielding killing machines. MPC’s concept art department designed these vicious demons, working with an initial brief from Overall VFX Supervisor Nick Davis. The creatures were to emerge from volcanic rock surrounding Kronos, but were not be too strong or large to fight humans on the battlefield. Director Jonathan Liebesman vision of the Makhai involved multiple arms and two distinct torso's and heads; MPC needed to understand how a character like this could fight, but more specifically how it would emerge, run and navigate through complex terrain while swinging swords. To visualise this, MPC’s concept, rigging and modeling teams collaborated to create motion studies which informed the final design. Having two body elements meant that the Rigging team had to be cognizant of not only the anatomical structure but also effect the split would have on this structure. Many iterations and clever solutions were undertaken to create the Makhai as seen on screen. “These were fun to work with,” says Anders. “We were working with Nick and Jonathan to get what they wanted.”

     



    The original idea was that this was going to be an aracnid kind of thing. It looks like a couple of mocaps strapped together but Jonathan wanted something more human so it could fight the solders in a more believable way. “They were two tortured souls of dead warriors, joined in hell and reborn to fight,” he quips. The concept team had a fight on their hands too, working out how these guys get stuck together and be able to fight all the time. The natural spinning and fighting were devised by tying two stunt guys together, but we found in the end the traditional way of using digital doubles so there were CG soldiers.
     

    Crowds

    MPC has their own crowd simulation software to create the crowds of soldiers, invented for the work done in ‘Troy’ almost ten years ago. Named ALICE which stands for Artificial LIfe Crowd Engine. This in-house crowd software has been used in over 30 films.

    The final battle required the development of a huge 3D environment, which was a combination of plates from two primary locations Tiede National Park in Tenerife and a very different battlefield location in south Wales. The initial eruption and Kronos’ path of destruction necessitated several weeks of specific aerial photography over various volcanoes and lava created terrain in Tenerife. The plan was to shoot all of it so the Editor, Director, Supervisor and all of the artists had an inherently realistic core to spring from that could be re-projected and altered significantly in post as required.


     

     


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