Massive Crowds in John Carter

Cinesite provided plenty of epic crowd shots using Massive for Disney's John Carter. Jane Rotolo, Lead Crowd Technical Director on John Carter tells us a little about using Massive in the production. Mouse-over the images below to compare the final composites with the Massive elements.

"For John Carter we worked on over 160 shots on 13 sequences and had a wide variety of shots to do. It was great to be able to work on ambient street scenes, marauding armies, fleeing civilians, airship crews and sword-fighting battles all on the same show, all involving cloth, smart stunts and dynamics. We had a fairly small team, briefly peaking at around seven but mostly around four or five, and we were lucky to have some really fantastic people.

Probably the biggest challenge on the show was just the sheer variety of things our crowds had to do - every sequence provided its own challenges.

For the AB and OB sequences (Air Battle and Opening Battle with the airships) we had to figure out the best way to get our crowds running around and interacting with props on the moving ships and also getting blown up and falling off the ships. We did some early tests using obj sequences as terrain to get the ships moving inside our Massive scenes, but at the end of the day we found it a lot easier to sim the crowds on a level, static ship at the origin. Then we could just constrain the sim back to the ship motion at render time and we weren't entirely dependent on a particular version of the ship animation which could rapidly become out of date. Sometimes the ship animation kept on being tweaked even well after the crowds had been approved, and because our sims were reasonably animation-independent we didn't have to keep updating our scenes and republishing every time. It also had the advantage that we could easily reuse sims in other shots. We wrote scripts to export shot cameras with the inverse animation of the ship so we could still preview the sim inside of Massive with the background plate and everything would look correct through the camera - even though the ship was actually static at the origin.

For the PL sequence (Palace of Light) we had around 60 shots of armies attacking and sword-fighting and fleeing civilians. We were lucky to have some great mocap performers who had been on set for the live action shoot, so we were able to get a lot of great sword-fighting and other mocap that matched exactly what had been shot. This also made an enormous difference to mocap rehearsal time! There is always a bit of setup time involved to import the mocap and build the agents, but once our combat agent was ready they could just be dropped into shots and away they'd go, fighting away quite happily.

Once we started seeing the first few shots in dailies we realised we had captured way too many fighting moves that ended with one of the performers being killed, I think because the stuntmen just enjoyed dying so much! So in those first few crowd shots the agents were dropping like flies, everyone was just getting slaughtered. The battle would have been over in minutes, so we had to turn the killing down a touch! For the MW sequence (Matai walks) we had several shots of hundreds of people clapping and cheering however, the shots were due before we actually had that particular mocap turned over. Luckily for us Massive is flexible enough that were able to get our agents fidgeting around and clapping procedurally. If you looked really, really closely they did look a bit odd but fortunately for us this was never noticed in dailies. We did eventually get the clapping/cheering mocap and swapped it out right at the last minute, just to be on the safe side.

Surprisingly some of the hardest shots we did were some of the quieter shots that you might not notice. These were the all-cg ambient street scenes with hundreds of agents just walking and milling about, as we just didn't have much variety of mocap. We were well prepared for all the 'harder' shots - the sword-fighting and attacking armies and the crews on the ships, explosions, etc, but we just didn't have a lot of mocap of everyday walks and all the kinds of natural interactions and reactions to things that you might see in a busy street.

I love that Massive allows a really high level of control when it's needed. Obviously we could do shots of thousands of soldiers storming Helium, but we also had a couple of shots where the performance of the live action extras wasn't quite dynamic enough and we ended up replacing them with Massive agents, in one case at about a third screen height! Luckily for us the camera angle was quite forgiving, and as they were soldiers they had helmets covering their faces, otherwise we might not have got away with it. Everything about those agents got tweaked to death, from the timing of their footsteps to the angles of their elbows. For such noodly work that might normally be handed to an animator, Massive actually handled it really well.

Another time, we had a shot where out of the blue one of the supes said he wanted to see a soldier dragging a wounded crew member across the deck of a ship, which we had absolutely no mocap for. I'm still not sure if the supe was joking, but one of the guys knocked up something using dynamics, ik grab and a few procedural offsets, and we had something to look at in dailies the next day. Massive is just up for anything, it really is so flexible.

Palace of Light

There were a lot of iterations to get this shot just right. The supes really wanted to see a lot of variation in the speeds of the soldiers, but at the same time there needed to be a clear leading edge. This seems to be fairly common in any shot where you have a charging army of some kind but with a front line that needs to be maintained throughout the shot. Of course the more variation in speed you have the more that front line breaks apart as the agents all spread out. So it was a fine balance of easing off that variation the closer they got to the front, and then picking out the few agents that still managed to race ahead too far. Luckily for us the shot wasn't too long, or that illusion would have started to fall apart.

The stunt people at the mocap shoot really seemed to enjoy running like crazy and swinging their swords around, so we added some of that into this shot to break things up a bit, and the swords nicely catch a few light reflections this way.

Air Battle

This is one of my favourite crowd shots on the show! The TD who worked on it really had a lot of fun with it. The agents had to react to the impact of the collision and the explosions in a realistic way, and this was done using a combination of mocap of people acting like they're losing their balance, falling, tumbling etc, and also a lot of dynamics and Smart Stunts. Massive really does this quite seamlessly. With Smart Stunts, instead of the agents just behaving like limp rag dolls there is a lot of life in them - you can really see them struggling but still reacting dynamically to the ship. We actually did a lot of mocap of poor stuntmen getting pulled around on jerk rigs as if they were reacting to an explosion, but the explosions in this particular shot got toned down to the point where we didn't really need that kind of violent reaction (although I'm sure after all that pain the stuntmen will be pleased to know we did end up using those clips on other shots).

We initially thought we may have to sim the crowd using an obj sequence as terrain in order to get the dynamics to work accurately and realistically, but a couple of the guys figured out a smart way to fake the direction of gravity, by turning gravity off and using animated forces instead, based on the ship's position and rotation. So they were still able to sim their crowds on a level, static ship at the origin, but if any agent fell or got blown up off the ship they would still fall in the direction that would look correct once the crowd sim was constrained back to the animated ship. This meant that for minor changes to the ship's animation - and the animation was often updated on a daily basis or even more - the crowd wouldn't need to be re-simmed every single time, and this really saved us a lot of precious time. Of course once the crowd is shaded, lit, graded in and covered with smoke and debris individual agents are quite hard to spot, but this is pretty normal for crowd shots!

We had so many challenges on John Carter. We had to deal with an amazing variety of tricky shots within a very tight time frame and with a small team, and thanks to Massive's flexibility we were able to handle anything that was thrown at us."