Setting Rogue One right before the events of A New Hope makes for a fascinating storyline that finally explains how the rebels managed to steal the plans to the Death Star. But it also posed a major challenge in terms of how to show the planet-sized weapon and other Star Wars spacecraft, like the Star Destroyers, on screen.
For A New Hope, the Death Star and the many spaceships that race across the screen were miniatures, made by George Lucas’s then-fledging visual effects studio Industrial Light & Magic. Now, ILM has 40 years of VFX might behind it, and has spent a lot of time leading the way in development of cutting-edge computer graphics. Ironically, that led to a major challenge: could the Death Star and ships in Rogue One, now rendered fully in CGI, still resemble the things audiences know so well?
For the Death Star, ILM’s secret weapon was visual effects supervisor John Knoll, who also happened to be a part of the team that came up with the story for Rogue One. Knoll said that he took on the re-creation of the Death Star in CG as a “fun hobby project.” Knoll revealed his side project in a presentation at this year’s Star Wars Celebration Europe event in London.
Back at the time of A New Hope, the Death Star was made as a spherical miniature for wide shots; fabricated pieces were built separately at different scales for shots of explosions on its surface or for spaceships flying by. The model makers often “kit bashed” existing plastic scale model kits, meaning pieces from model trucks, tanks, and warships could easily have shown up on the Death Star and other miniature spacecraft.
For his CG Death Star, Knoll began by referencing footage and photos taken of the miniature at the time. You might think ILM and Lucasfilm, which runs an extensive archives facility, could have just scanned or photographed the actual Death Star miniature. But, alas, they didn’t have it.
“It got packed up in storage case after New Hope completed and put into warehouse as Lucasfilm and ILM moved to Northern California,” said Knoll at Celebration Europe. “When the lease came up, someone said, ‘Get rid of what’s in there nothing’s valuable.’ So ILM doesn’t have the model.”
It turns out that the Death Star is now owned by a private collector. So Knoll had to re-create the Death Star for Rogue One, with all of its intricate surfaces in CG, without the key reference point. The worry was that it would be too good, and not have that “model kit” feeling. Knoll himself noticed in going back to the original designs and photographs from that era that the Death Star miniature had some unique properties.
“As part of re-creation I discovered something about the model that I can’t un-see,” Knoll noted in the presentation. “If you look at the outline, it’s not round, its pretty oblong in the southern hemisphere. I chose not to re-create that aspect of it.”
However, those photographs did help Knoll re-create the Death Star in CG form with the appropriate dimensions and textures. “You take a photograph and you match the photograph on a computer and then you project that onto the [CG] model and unwrap it,” he described. “If you do the same thing for a whole variety of stills from different positions at different resolutions, they become a master map.”
Then, for the spacecraft, Knoll went back to that kit-bashing idea, as he describes in a video released by Disney. “Since we were going to be building a great many assets of various kinds — spaceships and other bits of hardware — we wanted to make a digital version of the model kit library, so that we could take a similar process and hopefully the aesthetic would be continuous across the films that way, he says.
“So, rather than when somebody’s building a spaceship, building every nut and bolt on the ship, the idea was that if we built digital models of a lot of those original kit pieces — the artillery pieces, the tanks from the F1 race car engines — what if we built a lot of those same pieces and had digital versions of those?” he continues. “Then when the modelers are building, they can be selecting from those pieces, fitting them into the model, and the hope is that we are preserving that same aesthetic.”
Soon many Star Wars fans will be able to see a newly crafted Death Star, and spaceships made with the latest in visual effects technologies, yet still based on very much old-school effects techniques.