How MPC delivered this intense lightning moment in ‘Dark Phoenix’.

The third act of Dark Phoenix includes a dramatic rescue sequence, as the X-Men launch an assault on a train in which Jean Grey is being held. Looking to clear off some adversaries from the top of a moving carriage, Storm (Alexandra Shipp) rises up, commands lightning from the sky and launches that at the baddies.

MPC handled that shot, and visual effects supervisor Greg Butler breaks it down for befores & afters, including how Shipp was filmed, how the studio crafted the lightning and how moving backgrounds were achieved.

Shot methodology: They filmed a stunt double, going up on wires out of the train in a really great corkscrew shot. And then there were a couple of great plates of the actress, her close-ups, seeing her eyes go white. And then we really were pretty sparing in the use of her digi-double. We only did it in those moments where she had to hover against the train. But of course the train is moving at 90 miles an hour, and she has to be moving along with it. So it’s a combination of stunt double getting pulled up on wires, a close-up of the actress, and then the digi-double for the medium and wide quick action shots. And then there were stunt doubles on top of the train, and we had digi-doubles for them, too.

Making lightning: It was done in Houdini. We used lots of curves, trying to use a procedural setup for the bulk of the frenetic arcing motion. But it was also guided enough by an artist so that you could aim it at certain places, and so you can increase and decrease the number of arcs. Secondary branches were important. You would have a main bulb that says, okay, the lightning’s going to go here and attack this person, but there had to be branching off of it, to make it like a real lightning would do in trying to either get its way to the ground, or through something else.

Part of the difficulty of lightning is this: the core pieces are extremely simplistic, and kind of by their nature in reality are. It’s a piece of energy going from one place to another. And most of the complexity comes from the photographic part, what the light does. So we ended up having to have FX come up with the animation – where’s the arc, how thin is it, and how many branches? But then give comp a lot of secondary outputs – here’s how you can make it thinner, here’s how you can make it more broken up along the line in multiple directions. And then comp had to be very careful about how they would use any kind of glow treatments, because it’s a massive over exposure, which results in a lack of sharpness.

Then things like sharpness involve focus, and your eyes use that as a clue as to whether something’s near or far. So trying to give the lightning reality and depth, we had to be very careful that if you made it too soft in the foreground, it looked out of focus, which means it must be far away or really up close. It was such a delicate thing to produce in an image, in terms of exposure, softness, thickness.

And then you had to find that way of making it not too graphic, by using photographic treatments, but not using so many photographic treatments it looks like it’s not there, because it’s all soft and doesn’t match the sharp photography.

Synthetic backgrounds: There was an aerial shoot that was north of Montreal in a really nice area of forest along a roadway. And the roadway we knew was going to double for the train tracks, although it was really just a road. So when that was shot, we already started to realize that the nature of the sequence and the shooting conditions meant that the likelihood of us using the plate straight, without either augmentation or replacement of the landscape, was going to become unlikely. Partly because of the time of year, Fall came in so fast that the trees were not only changing colors, but a lot of them were losing their leaves. And it was no longer going to be the kind of green wooded area.

We considered trying a combination of grading and matte painted replacements of a whole big area of trees that were no longer right for the movie, or just acquiring as much of the landscape in-camera and using it as the starting layout for a fully digital forest environment with the tracks, which is what we ended up doing.

We basically took the photographed plates, if there was a helicopter plate, we kept that, because it’s a great element and we used the camera move because there’s nothing better than a real helicopter pilot camera move. And we replaced the road with a digital train track setup. And then we replaced all the hills around with the digital forest.

Follow along during this special weekly series, #makingtheshot, to see how more individual shots and sequences from several films and TV shows were pulled off.