Issue link: https://digital.copcomm.com/i/837213
www.postmagazine.com 29 POST JUNE 2017 To give the impression that Salazar and his crew of ghosts are trapped under the sea even though they move around above water, the artists at MPC devised ways to flow the costumes of 15 hero char- acters as if they are underwater. Two of the charac- ters are always CG. Actors wearing partial costumes played the others. "That was a decision we made early on," says MPC Visual Effects Supervisor Patrick Ledda. Ledda managed the group working in Montreal on the characters, while Visual Effects Supervisor Sheldon Stopsack supervised a London-based team working on water technology. "We could have had the actors in blue or gray suits," Ledda says, "but we decided to keep the practical [partial] costumes. They provided good reference for our look-development artists and the directors, and we could see how the ma- terial looks under lighting. The downside was that sometimes the costume was in the way. When that happened, we had to paint it out and replace it. With a blue suit, we could have put something on top. So, there were advantages and disadvantages, but overall, I think it was a good decision." The team created digital versions of each char- acter, costumed the digital models, and received approval from the director. Then to create the shot, they tracked and fitted the digital cloth onto the partial costumes in the roto-animated characters frame by frame. A team in Bangalore did the track- ing and roto-animation. "It had to be perfect," Ledda says. "Otherwise, you can get a strange jittering that you only notice later, and you have to go back to square one. We spent a lot of time initially to create rigs and con- trols to allow animators to really match the cos- tumes with high precision. It was a huge amount of work: There are many, many shots with ghosts, and lots of ghosts in those shots." The roto-animation drove the cloth simulation for the characters played by real actors. Underlying an- imation drove the simulation for the digital charac- ters. As with the hair, the cloth had to act and look like it was underwater. "Imagine a character is wearing a long coat," Ledda says. "As he walks, the tail of the coat lifts up and follows behind. Then, to give it an under- water feel, we add water currents. We placed invisible force fields in certain areas that would guide the simulation to give the cloth a little bit of nice, gentle movement from left to right. It's like on a real set when you set fans in certain areas." The challenge was in creating a simulation that felt slow even though the characters moved quick- ly – more quickly than they could have underwater. "Traditionally in animation you work in beats," Ledda explains. "You make sure a character moves from one shot to another in a coherent way. But, when it comes to more technical disciplines like simulation, they aren't used to working that. We had to learn to work in sequences. It took a differ- ent mindset." — By Barbara Robertson The crew on Salazar's ship aren't the only ghosts. MPC artists created ghostly birds, and for a long, complicated sequence, digital sharks. Here, Salazar's crew throw three dead sharks from the ship into the sea. As soon as they touch water, they start swimming and chasing Jack Sparrow (Johnny Depp), who is in a rowboat. The sharks jump the boat, attack it and bite chunks out of it — out of, in fact, a digital boat. Although the sequence has a few shots of the boat filmed in a tank, for most shots, Johnny Depp rowed a gimbaled boat on dry land. MPC artists surrounded the boat with water and sky, and put an island in the background. "There are very few pixels on the screen that are practical," says Patrick Ledda, MPC visual effects supervisor. "There were wide shots with water, and water in any shape and form is complicated. And it was a long sequence, with approximately 150 shots." To have the dry-land rowboat interact proper- ly with the digital water, the team built a placed digital rowboat in the CG sea. During the shark attack, they replaced the practical rowboat with a digital double and, occasionally, Johnny Depp, too. Then, toward the end of the sequence, the ghosts jump off the ship to join the chase. "There's a beat where you see the whole crew running on water," Ledda points out. "Those are fully computer-generated shots." — By Barbara Robertson Shark Attack Ghostly Costumes A CG A CG A undead shark gets shark gets shark into the action.