Issue link: https://digital.copcomm.com/i/863766
j u ly . a u g u s t 2 0 1 7 c g w 4 5 F E A T U R E simulation. By not approaching this as a monolithic solution, we could make sure the audience could read the action in a sequence like Crazy 8." The idea of simulation clusters came from techniques the crew had developed for the rivers in The Good Dinosaur, which had relied on the previous, Reyes-based incarnation of RenderMan. "We came up with optimizations and a new acceleration structure for RIS so we could break up simulations into indepen- dent clusters like we did for the white water on The Good Dinosaur," Reisch says. "The clusters don't know about each other, but by breaking the problem into component pieces, we could get the detail we needed for all those cars across lengths of track." The mud, dust, fireballs in the Crazy 8 sequence, the tire smoke… all these natural phenomena effects help make the world seem real, help the audience believe that real characters are interacting in a real world. Done well, the effects establish or heighten emotion. In one scene, McQueen crashes. He tumbles end over end, kicking up debris. There's roiling engine smoke. He hits the ground in slow motion with quick cuts, scraping along the track. "That level of realism helps make the au- dience care for the character," Reisch says. Some new technology helped the artists achieve that realism. "During that beautiful slow-motion shot where McQueen turns over in mid- air, we simulated the air flow around the car," Reisch says. "We do that for all the cars, but that shot shows it off. We do it as a pre-pass and then feed it into our high-resolution simulator." The technique has another application, as well. "The clusters of dust and smoke don't know about each other," Reisch says, "but the velocity pre-pass gives a percep- tion of these sims being tied together so they don't look completely independent from each other. It makes so much sense to break the simulations into clusters in space because of the amount of details. On The Good Dinosaur, it didn't matter if there was a piece of volume a quarter mile away. But we needed that feeling of velocity trailing right behind McQueen that we saw in our racing reference all the time." Mentoring Cars 3 is about mentoring. Hud and the old-timers mentor McQueen. McQueen mentors Cruz. For White and Reisch, mentoring extended beyond the story. White, for example, took on a co-DP for the show, Mike Sparber. "I picked him because he wanted to be the DP, but he was new, so I mentored him on the show," she says, "which is cool." Similarly, Reisch sees his role as su- pervisor including a responsibility to find artists and help them along the way. And, he appreciated the film's message. During the film, it becomes clear that McQueen's trainer, Cruz, had secretly wanted to be a racer, but people had not taken her seriously. Aer McQueen becomes her mentor, Cruz shakes off the debilitating judgment of others and wheels herself onto the racetrack. "My daughter was born a couple days before A Good Dinosaur released," Reisch says. "Seeing the message that [Cruz] can do anything she sets her mind to touched me deeply. She belongs on that track." As do we all. Barbara Robertson (BarbaraRR@comcast. net) is an award-winning writer and a contributing editor for CGW. ARTISTS IMPROVED HOW RIS HANDLES VOLUMES TO RENDER MUD, DIRT, SMOKE, WHITE WATER, AND SO ON EFFICIENTLY. THE EFFECTS ARTISTS SIMULATED AIRFLOW AROUND THE CARS.