Massive Crowds in World War Z

Cinesite yet again showed their Massive skills in delivering huge shots of humans and zombies for World War Z. Veteran Crowd Technical Director Lyle Cooley explains some of the Massive shots in our exclusive interview.

"We used Massive in quite a range of shots. The more obvious one being in the streets through Philadelphia at the start of the film, most of these shots had hundreds to thousands of agents - humans running in complete terror, trying to help each other if they can, and Z's chasing after and taking down the easiest targets. The ultra wide shot of downtown Philli and the surrounding highways had about 25,000 agents. As well as the more typical crowd shots we were also called on to add more life to many of the smaller scale shots, bulking out the existing on set extras, or in the case of many of the re-shoots where it wasn't possible to wrangle extras creating all characters on screen.

One of biggest initial challenges was setting up a workflow for promoting Massive agents to hero animation rigs. This was needed for when the agents got very close to camera and more per-character motion tweaks were needed to be applied. As all of the agent motion and variables driving things such as body size and the clothing the agent was wearing could be read from the Massive sim data, we were able to replicate that agent in Maya and then hand it over to one of our animators to control. Due to the large quantities of agents in many of the shots breaking the shot up into different simulations was very important. This was either done by having one main Massive setup and creating locator selection groups then at sim time processing a group, or splitting the setup into different areas, running these separately and then combining them back at render time.

One of the greatest benefits with using Massive was the quick adaptation to changes in the layout. Often the position of layout props (cars, shipping palettes etc) would be in flux until very late in the life of the shot. When changes happened we could take what we needed from the new layout, quickly adjust the existing Massive setup and run out the sim again. As the agents can adapt to their environment it's no issue getting 100 zombies to run around or jump over cars that weren't previously there."

Street scene

"This shot ended up having very little crowd in it as it needed to be so painstakingly fine tuned. There are some Massive agents in the background, and before it went through to animation blocking was done in Massive."

Aircraft carrier

"On the ship - we needed to add more people in to the existing on set extras (the real people).-To start with the extras at the edge of the group were roughly motion tracked, their position and movement on the boat was brought in to Massive for us to initially place the agents, and then for the agents to interact with (avoid, queue behind). Depending on where the agents were they were told to queue up or to shuffle along towards the main structure.- We had some motion capture that had people huddled and shuffling along, but to help get the point across the agents had a bit of brain procedurally offset the normal motion capture into a much more huddled position.- Using Massive added a directable business to the ship that was lacking in the original plate."

The bridge

"On the Bridge - The chaos was starting at the top end of the bridge and we needed to have people flood through the road block, not in a complete state of panic yet (and sadly no zombies yet in this shot). - The geometry of the bridge was brought in to Massive to start with. The low resolution versions of the vehicle layout was then brought in and lanes and flow fields were used to direct the agents through the road block. As well as needing to know which way to go, the agents needed to avoid running in to each other but also help each other out if someone was trailing behind. - As this shot is just before everything starts to really hit the fan, having control over the speed and urgency of the agents in Massive helped lead into the the ramping up of chaos.

Sadly these shots didn't have anything really unexpected happen. When the zombies were involved you'd get plenty of people bolting away from the general direction you might have first intended them to go because zombies were ahead. Or you'd get zombies finding their own shortcuts in the layout to tasty human flesh."

The square

"Shot looking down on the square - The zombies were on the loose and on the hunt for humans, we needed to provided a sense of rushing out of the city, flowing through the stopped cars and streets. - This is a great example of a Massive shot. As the agents are acting on their own accord with a purpose, you get sense of the people running away with a humanistic feel, drawn together as they don't want to be on their own. And then you get the Z's that have no order, they only care about eating brains and barely notice anything else around them. - This is one of the shots that you'd get humans finding some small unplanned escape route and barrelling off in a direction you didn't intend on them to be going."