Space battles are synonymous with Star Wars films. The original trilogy is fondly remembered for ILM’s use of motion control and miniatures. These days, like on The Last Jedi, digital ship models, photorealistic rendering and simulated crashes and explosions are of course the norm.

But to ensure the space battles in this latest Star Wars adventure echoed those memorable scenes from the first films, ILM employed several ways to bring them to life, even starting an in-house project to copy – at least to some degree – the look and feel of the original motion control miniature movements.

vfxblog recently visited ILM London to find out more on that process, plus a whole bunch of other things about the scenes in which Poe Dameron (Oscar Isaac) takes on the Dreadnought, and when Kylo Ren (Adam Driver) launches his spinning attack on the Resistance cruiser.

1. ILM had a special project to make sure the space battles echoed the originals (and even considered doing them practically)

With CGI, the space battles in The Last Jedi could clearly be almost anything. But that wasn’t what director Rian Johnson wanted. Instead, he looked to echo what was familiar – and what was so well-regarded – from the original trilogy. But interestingly the space battles there, made up of computer controlled motion control miniature elements layered together optically, were somewhat limited in which way ships and cameras could move. CG of course gives modern-day filmmakers more freedom, but Johnson and ILM deliberately limited any dramatic camera moves, or let the original films at least inform the shots.

What helped was an effort inside ILM to mimic that original look and feel (the studio even bid out how much the sequences would cost to do practically as miniatures, but this proved cost and time prohibitive).

“Luckily, we had Dennis Muren here,” says ILM animation supervisor Steve Aplin. “And obviously he was driving a lot of the initial effects work on those first films. He was also driving an experiment at ILM where he actually took some of the old footage of Star Wars, and got us to do CG versions of those shots, and then spoke to us all about them, asking, why does this work and why doesn’t this work? And what are the differences, and what can we do with the cameras?”

“It was just a great lesson in how much you can move the camera,” adds Aplin. “And that drove itself into the destruction of the vehicles as well. We took it as a base, and just very much paid attention to, ‘Well, why did that feel real?’ And a lot of it is simplifying. Less is more. You don’t have to do so much.”

Out of that process, Johnson generally moved towards “simpler, more storytelling cameras – he wanted it to be very graphically obvious what was going on in each shot,” states Aplin. “And we could take it to the edge of what we felt was reasonable within that, so long as it told the story. There’s only a few shots where we really pull away from this simpler sort of structure of the cameras and the language that you had in the original films.”

One direct example where that approach was used occurred when Poe is doing some low-level flying across the surface of the Dreadnought and is slaloming between the different turrets to blow them up. ILM referenced shots here from Return of the Jedi of X-wings flying across the Death Star surface. “We did some very basic matchmove tracking to those shots from the film, and then put them into the space of our Dreadnought,” outlines ILM visual effects supervisor Mike Mulholland. “We didn’t use it directly, but it was there showing how the ships would move when the camera moves at certain speed and how it operates in some spots.”

2. ILM’s model kit process continued on this film

Another way in which the spaceships of The Last Jedi were linked to the original miniatures was the manner in which they were modelled. ILM covered the surface of some of the ships with a set of CG kit parts (affectionately termed ‘greeblies’), modelled directly from original kit parts. That process was also used on Rogue One. Says Mulholland: “We’ve added to that set of kit parts, so I think each film there will be a few more bits put into it. That kind of helps for a multitude of reasons. It keeps it feeling there is a timing to the original way these ships were manufactured. They were using a common geometry, scale and pieces. It’s quite subtle, but there’s a commonality for it.”

“Our aim was to try to be able to have an X-wing, a bomber and an A-wing and have them all parked up together and make you feel like they’re from the same universe,” says Mulholland. “Like it’s not a new ship. It’s a new ship, but it’s an old warhorse kind of ship. It’s done service. They’re not fresh out of the factory. They all have to co-exist together.”

3. Like the original Star Wars, the space battles were based on classic war films

Even before he managed to get ILM up and running and implement a motion control approach to the space battles in the original trilogy, George Lucas had imagined the battles as classic World War II dogfights. He even roughly edited war footage together to serve as inspiration. So, in again echoing the origins, Rian Johnson also referenced old films.

“Even the very early description of the things like the bombers and the dreadnoughts, it was like Dam Busters,” recalls Aplin. “We were all talking about the classics. Even films that aren’t Star Wars. We were talking about Das Boot, and the tiny little fuselage, or the submarine fuselages, and the claustrophobia, and the components in Lancaster bombers, and the rattling bombs. The entire thing was grounded in a sort of group understanding of what we were trying to achieve.”

4. Practical cockpits added another layer of believability

Although the ships are fully CG, the actors were still filmed performing in full-sized cockpit mock-ups, although no glass was included so that was added later. The cockpits were also positioned on a motion base to provide movement. For realistic light interaction, cinematographer Steve Yedlin pre-programmed a series of lighting cues to match laser blasts (called ‘pew pews’), explosions and other general lighting to the final visual effects shots.“One of our operators was in there driving them on an iPad,” explains Mulholland. “When they’re on the shoot, they’ll do an interpretation of what the current placement was at that point. For us it’s a mixture of trying to take a lighting cue, which is just in the plate, and then justifying it with something, which is happening in CG, like a bolt that flies back really closely.”

5. Poe’s classic hand-brake turn was a key moment

In order to evade attack, Poe comes up with a neat hand-brake turn in his X-wing. For ILM, this proved tricky to pull-off, mainly because audiences hadn’t seen an X-wing do that kind of thing before. “The Third Floor had previs’d that shot and it was working fairly well,” discusses Aplin. “We just needed to really work on the physics, with just selling that as much as possible.”

What eventually sold the shot more than anything was an editorial choice to split the shot. “It was one long shot originally of Poe flying through the gun he’s just destroyed, through the explosion, and he pulls into his handbrake turn, and it’s all in one shot,” describes Aplin. “Once we punched in for a couple of little inserts, it just really helped with the pacing of that very small little chunk of shots, to sell it as a real moment, rather than too much of a visual effect.”

6. Physics mattered, even in space

That hand-brake turn is pretty way out, but even so ILM had to consider the bounds of physical plausibility in space, at least to some extent. This was an overriding factor for Aplin in discussions with his animation team on the space battles. “Obviously you’re trying to get a performance, and you’re trying to tell a story. But no one’s going to believe that unless it works physically correctly. The physics of the character, that it doesn’t move too quickly, or it doesn’t move too fluidly, that’s there’s some natural chaos in its movement.

“I’m always driving home with my animators to pay attention to how quickly it’s moving in camera space,” continues Aplin. “Could it turn that quickly? Could it do a barrel roll? And if it does do a barrel roll, can it do it in the time that you’re trying to do it in? And then, of course, you try and play other small secondary animations on top of that. If there’s anything, a vehicle like the X-wing, add some small bits and pieces that we could actually move and flare, and help to drive the physics of any of the action.”

7. How the ‘space cow’ bombers came to be

Bombers (Aplin says Johnson called them ‘space cows’) are new to the Star Wars world, and their design and movement was part of a deliberate design effort to be a little meandering, but equally as effective if their bombs are released. Still, their exact animation continued to be refined.

“We inherited an idea, which The Third Floor had, which was, because they are basically a huge fuselage with a hanging structure, they were like pendulums, floating in space,” says Aplin. “It was a really interesting motion to watch, but again, Rian came back to us to say, ‘They just don’t feel physically real. They wouldn’t be able to swing that fast. They wouldn’t be able to do that. Slow it all down.’

“So we really did simplify their motion as much as possible,” adds Aplin. “We tried to, again, back up some weighty physics with secondary physics, which you as a viewer don’t notice too much on first viewing, but, you know, these are like World War II old bombers. They’re basically on the verge of falling apart. We added tonnes of secondary shaking animation, different panels rattling, and the engines are flaring, and there’s pipes, which are rattling like they’re going to fall off.”

8. Blowing stuff up in space is fun, but a lot of work

The bombers don’t fare too well in the opening space battle, although one long craft does take out a massive First Order Dreadnought. To have the bombers and other ships explode realistically, ILM began the process by building in specific breakages in the ships.

“For the bomber for example,” says Mulholland, “we’re building the outer shell. We’re building it with a thickness to the panels. There’s an actual interior to the magazine, which is the big metal strut hanging from the base of it all. So it’s got a volume to it during the build, and that’s super important so when we are blowing it up we don’t want it just to turn into like a pinata, where it’s filled with junk. We want it to feel as it explodes there’s a purpose and there’s a reason. You can slice through that slip in particular, and you’d have a real nice cross section showing you how it was built and how it was designed.”

The next stage is simulating fire, debris and destruction. ILM improved its destruction pipeline to add even more components, enabling ships to shatter into more pieces, with these pieces being connected and interlocked together – not just individual pieces flying off. “You’d have chunks, and then the chunks would be able to break up into smaller chunks, and they’d be able to break up into smaller chunks,” explains Mulholland. “It was a bridge we took, which was using a Houdini set up allowed us to do that.”

Aplin suggests the breakthrough here is that ILM can go for huge spectacle with digital effects simulation tools such as Houdini, or it can use the same tools to copy what a practical explosion may have looked like.

“For example,” says Aplin, “I’d show the special effects supervisor Chris Corbould the tests that we were doing in Houdini. and Chris himself just turned around and said, ‘Christ, I’ve been blowing things up for 35 years and I can’t tell the difference.’ To me that was suddenly, and hopefully, a breakthrough for Rian, where it’s just like, ‘Rian, we can make it look like shiny modern CG or we can make it look like balsa wood models.’

9. ILM had to develop a new way for Kylo Ren to fly

Kylo Ren, piloting his sleek Tie-fighter called the Silencer, embarks on a mission to take out Princess Leia’s Resistance cruiser. While he pulls out of firing at the last second, his accompanying ships do. First, though, he shows off his skills at destroying Resistance ships inside the hangar by spinning past laser canon fire.

“That was interesting because Rian was really keen that this is the moment Kylo shines as a pilot,” says Aplin. “We haven’t seen it before and so this is where he needs to show what he can do, but there weren’t many shots to do it in. The initial shot where he approaches the Resistance cruiser, and we’re looking down the ship towards the back, and seeing him come and swoop down, was far simpler in early takes. We made it more and more expert-like.

“I think if we’d tried that on any other ship, I think Rian would have said, ‘It doesn’t feel right. It’s not physically correct,’ because he spins really fast. But for this one moment, he wanted to break the physical laws and just like, ‘You know what, I’m gonna show that he can do this. He can pull around, he can cut back inside.’”

10. Audiences need to look closely during the space battles for easter eggs…maybe

There’s a lot of detail to take in during the space battles. In the past, ILM has hidden a few fun Easter eggs for eagled eyes fan, but did they do that in The Last Jedi? Aplin told vfxblog, “There probably is stuff in there. I’ll say yes, just to keep you going back and looking. There are some bits and pieces that were definitely snuck in there.”

So, keep an eye out perhaps when the Blu-ray is released. (By the way, Aplin says take a close look during the Maz Kanata sequence, too)…