"Because of the size and scale of the project from the outset and intrinsic to our plan was Universal and Guillermo allowing us to sub-contract a certain amount of the work. We assigned shots to Cube Effects in Hungary, and to The Senate, LipSync and Baseblack in London. This enabled us to stretch the incredibly tight budget as much as possible, and still maintain the high quality demanded by Guillermo [del Toro]. Also, we took the decision to split the job internally into two parts. Both team had their own production and supervision teams, whilst still being part of the team led by myself, Eamonn Butler and overall VFX Supervisor Mike Wassel."

The first team was led by Digital Effects Supervisor Andrew Chapman, VFX Producer Andy Taylor and VFX Coordinator Antonella Ferrari -- and the second one by Digital Effects Supervisors Adrian De Wet & Justin Martin, VFX Producer Moriah Sparks and VFX Coordinator Karen Clarke.

This fully CG shot features a digi-double Abe and CG water.

Design and Rigging Challenges
Most of the creatures were built based on scale maquettes designed at Spectral Motion and Solution studios. However, the Golden Army soldiers started off as a rough drawing and were developed at Double Negative by Graham Jack and Jay Davis and their Golden Army crew. "During the built process, we changed the gait of the soldiers walk cycles to enable the Golden soldiers to feel heavier," Garrard remarks. "So, the legs changed length and this drove how big the practical steps were built on the Golden Army chamber. The other major evolution that we did to the creatures was the addition of the 'pimp coat' onto the Elemental, the giant monster that appears during the climax. This jacket of vines helped give it scale."

The members of the Golden Army turned out to be the most complex build and rig, due to the sheer amount of parts, and their complex and intricate nature. The team describes them as beautiful Swiss timepieces that had to emote anger, vengeance and pathos... The robots also proved difficult to animate. "Every joint, plate, cog, etc. needed to be hand animated, and there were hundreds of moving parts," Butler says. "Every time a robot took a step, each plate of armor, rib, joint, etc., needed to jiggle at a particular frequency to indicate the weight hit. Also, the robots have the ability to rebuild themselves. All of the robot parts that litter the floor had to be rigged and animated, as the robots are progressively destroyed and later rebuild themselves..."

Jack was CG lead on the sequence: "We had a main rig controlling the performance, but there were also secondary cogs inside the creature that were primarily driven by its movements. On the hero moments, when the creatures were reforming, the rigs were all custom rigs and hand-animated."

It took a lot of work to animate Elemental's appealing shapes and motion with its many tentacles because of the complexity of the animation controls. 

Double Negative's asset management system was used to control the level of detail of the robots and their visibility in the scenes. The team tried to keep the geometry as light as possible, but employed ReadArchives to pull the high detail geometry at render time.

Multiple robots shots were rendered by breaking down the scenes down into foreground, midground and background. "We also ran a preliminary bake pass before rendering the beauty pass," Martin explains. "It helped speed up subsequent re-renders for lighting changes. The beauty passes had a set of secondary output passes to give the compositors more control over the look of the robots, which helped reduce the re-renders needed. For a few of the wide shots, we used particle based instancing of hand-animated cycles."