MPC CG supervisor Chris Downs details the production of 350 visual effects shots for director Ava DuVernay’s adaptation of ‘A Wrinkle in Time.’
Serving as one of the lead visual effects vendors for Disney’s A Wrinkle in Time was MPC, led by VFX supervisor Pete Dionne, who was supported by CG supervisors Chris Downs and Ryan Mintenko in producing 350 shots. The bulk of the work took place in cave of the Happy Medium (played by Zach Galifianakis), and the most complicated task was creating the forest monster that chases Meg Murry (Storm Reid) and Calvin O’Keefe (Levi Miller), while additional contributions included a planetary view of Camazotz being consumed by a virus-like entity.
In an effort to locate her missing father, Meg, along with her brother Charles Wallace (Deric McCabe), classmate Calvin, and three celestial beings known as Mrs. Which (Oprah Winfrey), Mrs. Whatsit (Reese Witherspoon), and Mrs. Who (Mindy Kaling) head to the cave dwelling of the Happy Medium. Special effects supervisor Mark Hawker created a series of teeter-totters for the actors to perform upon as the set was designed to emphasise the theme of balance. “We found a way to blend between the on-set piece and the crystalline that we developed; it allowed us to sharpen edges and get an extra glow or a light coming through them,” Downs notes. “Getting on-set lighting reference was critical in getting that look because if you start to add lights where there weren’t any it separates them from what was actually happening. The compositing team did an outstanding job of figuring out this template of how to take these crystal renders, the plate, and add the right amount of details to have them sit properly in that scene.”
The best crystalline reference was selenite. “Lamps are often made out of selenite with a light placed in the middle of it,” Downs remarks. “You get this nice soft glow but also some hot pings on the edges of the crystal. That’s where we ultimately ended up with our look development. Then it was a matter of pushing those details back into the plate where it was needed.” Witness cameras proved useful in determining the whereabouts of lights placed away from the set to cast an overall ambient glow. “We studied those intricately to make sure that we had the lighting correct,” says Downs. An extensive amount of the plates was incorporated into the final shots with no digital doubles being required. “We did roto animate the actors in a lot of cases in order to get correct shadowing and interaction with the lighting,” he adds.
Transforming a forest into an adversarial force chasing Meg and Calvin was a complicated process involving multiple layers of simulations. “It started with a layout of the overall structure of how this thing was going to break apart and somewhat twist as it erupted from the ground,” explains Downs. “We blocked that in with some pieces of ground that were made into digital assets. Once we got approval from [director] Ava DuVernay, it was pushed through a Houdini simulation in order to get the correct fracturing to the look of the pieces. Then we had additional simulations for crumbling and breaking at that edges; volumetrics for dust, dirt and debris that are falling off; and trees, little ferns, bushes getting ripped up and pulled into the swirl of this thing.”
A flexible system was implemented that enable pieces that were not looking good in a shot to be art directed. “Sticky projection allowed our environment artists to go in and paint on these pieces after they had been simulated,” Downs recounts. “We looked at a lot of reference especially of tornadoes. To convey a sense of scale we had these little ferns and puddles.” The final image needed to have higher contrast than the overcast lighting found in the plates. “We kept a 10-foot radius around the actors and merge that back into our environments. But for the most part we did a full background replacement.” The practical elements established a clear target for the digital versions. “It gave us a great starting point for things like leaves blowing. The rain was an excellent reference in that we got to see swirling, gusting and misting happening as it was all unfolding.” Not everything happens at ground level. “As we get into the top hat, the column that leads up into the sky and connects with the clouds, that whole vortex was two or three separate simulations.”
Instancing assisted with the trees and bushes. “We had slower and faster moving versions of each of these things to show the progression of the forest monster moving through the scene,” Downs observes. “The tricky part with the lighting was integrating all of the pieces together and making sure that everything was casting shadows correctly onto one another. We were fortunate to have an experienced lighting lead who setup a system whereby it was templated so that any artist looking at a particular shot was able to quickly determine which passes were not visible to camera. We culled out any data that wasn’t needed. Rocks were rendered separate from volumes although they did cache out with one another.” Keyframes were taken from priority shots. “Once we’re happy with the keyframes we did a full sequence render of those three shots to see how it looked in motion and with everything in there. We would then start to make little adjustments and put that into the children of those key shots. It gave us a nice overview of how the sequence was progressing,” he says.
“We had the precursor to the forest monster where you see a lot of these trees starting to sway and break, and a huge dust cloud moving forward,” continues Downs. “We had to integrate our moving dust cloud into the plate. A CG proxy version was built of the plate to generate a simulation that interacts with everything and moves between the trees. It ended up being three or four separate simulations: foreground, midground, and overall dirt, grit, and debris.” Cause and effect needed to take place between the different simulations. “They often will play off of one another. We create another simulation based off of what that first one is doing. Potentially that can continue a couple more layers down as the simulation that was caused by the original causes another which then causes another. If they cascade into a big enough effect it is then dumped back into the original simulation and that kicks off another round.”
Editorial changes resulted in the prelude to the forest monster sequence becoming the aftermath. “The challenge there was the wardrobe and hair were different,” Downs notes. “Meg’s hair was tricky based on the curls. The weight and bounce of it is quite a hard thing to do especially when you’re that close to camera as she is in the wheat field sequence. You also have these little flyaway hairs which are what gives that a sense of realism.” The forest monster needed to dissipate. “For the last two or three shots we needed to do per shot simulations because there were specific story points for each of them. As it’s dissipating the force that was holding it all together loosens so we needed things to fall out in a way that looks like everything is being released.”
An outer space view of Camazotz showcases it being consumed by a virus-like entity. “Viruses have this weird squirmy feel that tied in well with this constantly changing planetary idea. It has tendrils and arms reaching towards Earth,” Downs remarks. “We also looked at oil slicks and a beating heart to draw inspiration for the movement. In the end we removed a lot of the fast twitch type of motion in favour of these larger slower moving things to help sell the scale.” It was important for the evil antagonist to be “gross and icky.” “It was a heavy tech animation effects build to get the look and feel. The environment team was heavily involved in making sure that we had surface detail and interactivity.”
Artist license was taken with the lighting of Camazotz. “To be true to space we wouldn’t have a lot of sources of light out there but given the scale of this thing we were handed a bit of liberty to play with,” Downs explains. “If it was able to swallow a star then a star should be able to light it. We were able to cleverly place a few lights that caught some of the details. It became a game of trying to backlight and rim light this thing to keep it mysterious but also extract enough detail to make it feel like something that you don’t want coming towards you. We used a cloth-type simulation on the main bulk of Camazotz and fluid simulations to help drive the look and feel of the tendrils growing and reaching out.”
“There has to be constant communication between animation, tech animation, effects and lighting which have moving pieces at different stages of completion,” observes Downs. “The big challenge was bringing everything up to the same level all at the same time and making everybody aware that these are not final. We stuck mostly with the way our pipeline works.” Production visual effects supervisor Rich McBride and MPC visual effects supervisor Pete Dionne had backup plans to accommodate the in-the-moment filmmaking style of DuVernay. “Rich was on-set with Ava, so he had a feel for how she was going to be working and her process. We always had something developing in the background that was going to lead towards some flexibility if Ava decided to do something differently. Full credit to Rich and Pete as they were on top of that throughout the whole show.”