Stuck on Sakaar but looking to get back to Asgard, Thor, Valkeryie and Banner steal one of the Grandmaster’s ships, the Commodore. In a high octane chase scene through the city, they escape Sakaar fighters and exit through a wormhole.
Digital Domain crafted visual effects for the Thor: Ragnarok sequence, overseen by overall visual effects supervisor Jake Morrison. Morrison and DD’s VFX supervisor Dave Hodgins explain how the exciting chase was pulled off.
Morrison: Taika really wanted to get across the feeling of a really intense manual transmission stick-shift car chase. He really wanted to do like the early George Miller stuff, and the late George Miller stuff too, but particularly we kept going back to the cameras mounted on the dash on the Interceptor like on the original Mad Max film. As if you’re actually feel the transmission being shifted all the time.
There’s also a subtext where it’s actually kind of a courtship dance, which I think is a kind of hysterical sub-note, which is when Thor sees Val and she slaps into the windscreen and then you get the, ‘Get inside!’, and she says, ‘In a minute!’ And then she runs off and does the supercool jump off the back of the ship and then lands on the other one, starts ripping the ship apart, then jumps onto the next one as it explodes and drops. Thor looks back and he’s definitely gone a big goo-goo eyed, and he’s like, ‘I probably should go back and help.’ It’s like courtship dance where they’re really just trying to impress each other a little bit, and it’s like two peacocks strutting their stuff, which I think is really quite sweet.
To film the scene, having an insane amount of wind was the only way we could do that. We still built all the spaceships, but they’re basically all just wooden stand-ins. We did it all in the car park actually out the back of the studio, and just really asked our special effects brothers and sisters to just bring all of the wind, please. The point was, if you’re in an open-top car and it’s going 30 miles an hour, you’ve got to shout. So if these people are actually standing on the top of a spaceship going at Mach 4, fine they’re Gods, but at least their hair’s got to be doing something, you know?
Hodgins: Some shots required 100% digi double and others were digi double hand-offs to the plate. In one shot, we went from Valkyrie digi-double to actor and back to digi double. In terms of animation, we ended up hand animating or roto-mating most shots. A couple of shots we used a Xsens MVN suit that let us capture a few reference moves without setting up a whole motion capture session.
The challenge for us was not about building a city per se, which we’ve done before, but building enough city to fly through at 500 mph. Our original city would only cover a couple hundred frames and we’d have to reset the camera. Asset-wise the city was a lot of work for lookdev and textures. The visual development for the city hadn’t been finalized when we started the sequence so we helped experiment with looks and color schemes for Sakaar. It was meant to be a very colorful city but we hadn’t defined if it was neon or pastel in its hues yet. On top of that, director Taika Waititi wanted the city to feel lived in but not industrial which steered our choice of windows, traffic and atmospherics.
The wastelands of Sakaar were much easier problem to solve. We populated these shots by procedural garbage scatter using a big library of debris and hero models. We created proxy mounds that would designate where these garbage piles would exist in our animation renders and these would be turned into fully detailed garbage stacks in Houdini. Then white water would be generated around the piles so they sat in the ocean surface nicely, with hero splash elements added when needed.
The destruction of ships and buildings were accomplished through our Houdini pipeline. Using gas sims for explosions and fluid sims for the splashes of ships crashing into water we straddled the line of realism and readability. With the ships flying at such high speeds some effects would become blurs and lose the detail that we wanted. Some smoke volumes needed to be bigger just to stay on screen long enough so there were various cheats taking place to carry out the story point in each shot.