There were also issues getting the right type of lighting, and the crew was careful to make side-by-side comparisons of Cushing’s original Tarkin footage and Henry’s performance so they could keep track of the former actor’s physical tics.
The main rule the animators followed, according to Hal Hickel, an Industrial Light & Magic animation supervisor, was that “realism had to trump likeness.”
Starting off, Guy Henry wore motion capture materials on his face during Rogue One’s principal photography, which John Knoll described as “a super high-tech and labor-intensive version of doing makeup.”
It’s a good thing, then, that Lucasfilm pure all that time, energy and expense into pulling off this incredible feat of movie magic once they’d secured permission from Peter Cushing’s estate.