One of the scenes, as brief as it is, that really caught my eye in Thor: Ragnarok, was the Bifrost journey taken by Thor, Loki and an uninvited Hela. A mid-journey fight ensues, which ultimately sends Thor and Loki to the planet Sakaar.

We’ve seen the Bifrost before, but this time visual effects supervisor Jake Morrison and visual effects studio Rising Sun Pictures made it somewhat more crystalline. They also dealt with what happens when a character strays through its edges, coming up with a technique that included just the right amount of camera shake. Morrison and RSP 2D lead Jess Burnheim break down the work for vfxblog.

The scene was filmed on bluescreen, after being blocked out in previs. “We shot the actors on these big tuning forks on a tall soundstage suspended 30 feet off the ground,” says Morrison. “I’ve learnt from doing this type of thing before that you’re always five minutes away from looking like a couple of actors standing on apple boxes, and that is just not cool. So we almost went to the opposite extreme and made sure that it looked like the actors really don’t feel like they’re standing or supporting their own weight. You can get these weird angles and perspectives on them that you couldn’t get normally if you were just standing them on a box.”

Still, in post, there was more Morrison wanted to do with the scene. “We were just riffing, and we thought, ‘How can we make these shots feel more exciting?’ If we were doing a car chase with that kind of movement, you’d have the door open and they’d be leaning out and being pushed towards the road whizzing by. Then if they had any metal on their suit, if there was armour or anything like that, you would literally see this wash of sparks. So you would have this real connection with the audience that you could see the speed and the violence of the moment.”

That thinking lead to the idea of sticking a head into the edge of the Bifrost. When that happens, the head and bodies are hit with a barrage of Bifrost crystal shapes. “It’s almost like their bodies become like an umbrella in a huge shower of crystal shards,” adds Morrison. “It starts feeling violent, and I kind of knew that the sound guys at Skywalker would be able to run with something like that and give us a really quite immersive experience.”

“We tried shafts of light but it did not feel dangerous or exciting enough,” adds Burnheim, in terms of what Rising Sun Pictures devised for the shards. “We also tried a splash as if someone fell from a boat and hit the water at high speed but when simulating at the correct speed became messy and confused the story.We finally settled on a shattering effect which tied into some of the refractive nature that we had built into our initial look of the Bifrost. We played with speed, size of the shards and the lighting influences our characters had on their surroundings to give us the final look.”

Rising Sun Pictures built the effects parts of the Bifrost in Houdini and then composited together 12 separate elements. “After many iterations in FX and comp, we settled on a template-able build which then could be rolled out to other shots in the sequence,” says Burnheim. “Once we started to see other shots come together, it became clear that slight changes like focal length or camera angle could really have an effect on the dynamics or perceived speed of the Bifrost. In the end, it took quite a bit of back and forth between the two departments on every shot to get just the right flow.”

“Another challenge we had was that the plate photography supplied was quite flat lit so in the end we either replaced what we could with digital characters and relit them with a version of our pre-comped backgrounds to get the lighting interaction just right,” adds Burnheim. “We would then lean on our layout department to tightly match move the plates so we could also use certain passes from lighting to relight the faces of the characters to really sell that they lived in the same world.”

To add even more dynamism to the scene, Morrison pushed for some extra camera shake, but realised in a more ‘analogue’ manner. “We’d go out with a camcorder and shoot some really shaky footage, then you track that and then you apply that as camera shake, as transform, so everything smears out, but then you remove the transforms and you just apply the motion blur. What happens, as somebody is flying towards you, like the shots you see of Thor rocketing towards us, all the motion blur is telling you that you’re in the middle of this mad camera shake moment, but he’s not actually translating around the screen. It’s kind of a weird look and it’s really fun but it adds this sort of frenetic feel to a sequence. I think Rising Sun did an amazing job on that one.”

Among many other shots, Rising Sun Pictures also orchestrated the visual effects for the Valkyrie flashback, which featured super-slow mo footage shot with a Satellite Lab rig. Rising Sun worked on the extensive environments as well as some neat wing additions and CG horses and riders. See more about the sequence in my piece at SYFY WIRE.