Bobby Roberts
Banned
Was talking about the digital de-aging and re-creation this weekend on twitter, and while I know I can't really speak to the technical aspects of why things do or don't work very well, I think I can at least point out some directorial decisions that might have at least contributed to why the effects didn't quite work the way they were intended, because it seems to me like the work itself was very, very, very good, but the ways in which the filmmakers chose to implement that work is what caused the disconnect.
So, here's the CG model for Princess Leia:
That work is pretty damned amazing. "But of course it looks good! It doesn't have to move. It just has to sit there and look like the still of Carrie Fisher from 1977 in the upper right!" Well, yeah. But even getting the fully CG model to so closely replicate that still to the point it's almost indistinguishable (and for a ton of people, it is, is still a pretty amazing feat.
But yeah, the problem is that once the mouth starts moving, the effect's believability starts to sufferfast:
Now, I don't know if that's a case of them not having enough time & money to get the de-aging down, or if it's a case of them having too much time and they just over-tweaked the thing until they wound up with a face that frame-by-frame looked right, but in motion read as very wrong. No clue. But I can tell you that somewhere between that model looking spot-on, and that model being made to say the word "Hope," something went awry.
And I think what went awry were two things, and both of them were directorial in nature, not technical.
(1) The decision to show her at all breaks continuity
This doesn't make much sense considering the whole point of her being there is because Rogue One appears to be a film that was made with one eye, at all times, on the notion that you're supposed to watch it directly before Star Wars. Yes, audiences could just accept the hard fact of this film having been made 40 years after the film it is immediately preceding, but everyone involved decided to try as best they could to make it match as seamlessly as possible.
Since that's the case: Deciding to show her at all breaks continuity. Because George Lucas obviously wanted to hide her identity until after she'd given the plans to Artoo. She's on the ship, but we don't know who she is yet. All the shots are selected carefully and arranged just so, in a way so Leia's "reveal" is meant to be the steely-eyed, determined young girl with a gun in her hand who isn't going to take any shit.
Now, the first time we see her is this:
Which brings us to (2) Leia is out of character
Now, not only are we seeing her, but the direction here doesn't make sense for either Rogue One, or Star Wars. Why is she so full of starry-eyed hope? How does that make sense for her character, especially at that moment? Immediately leaving the Battle of Scarif, and right before Vader personally snaps the neck of her captain and takes her hostage after getting shot, we get a moment of her doing this 100% idealistic, soft-focus, sadly happy reaction to getting the plans?
It doesn't make any sense, really. The emotion we're seeing Leia try to pull off there is an emotion Leia almost never shows in any of the films, and especially not in moments like that. Which might be helping with that uncanny valley vibe of the animation a lot (i.e. "why... why is she so happy here?") as well as making it harder to animate her face convincingly in the amount of time they had. If she's determined, or focused, or even slightly angry at what the Empire's just done, maybe that line plays better, and maybe that emotion is easier to essay in the few seconds she's onscreen.
It's not really a matter of the work being bad. The work is good. The way the VFX team was directed to use it sorta sabotaged 'em, I think. Same thing happened with Tarkin - that model's been posted in here already, and again - it's a great model. They put in a ton of work to make that effect believable, and most of the time, it shows.
But as per this IndieWire article, you realize that what they were being asked to do with the effect (and how they were asked to do it) sorta diminished the best possible applications of it: Tarkin looked perfect under specific lighting, but they didn't manipulate the lighting on the Death Star scenes in post to allow for that effect to work correctly. Henry's performance was great, but because his mouth movements weren't 100% like Cushing's were, they went in and hand-animated the mouth. Did they overwork it? Did adhering to 100% frame-by-frame fidelity to a dead man's movements (a fidelity maybe 0.0001% of the audience would even notice) cause uncanny valley instead of mitigating it? Who knows.
They probably coulda never showed Leia's face and just put some makeup on Guy Henry and called it a day, really. Maybe they shoulda. Guy Henry looks like Peter Cushing enough that it wouldn't have to be that weird fright-mask they slapped on for Episode III. And considering the film features a completely different actress playing a Mon Mothma set something like 3-4 years before Return of the Jedi, audiences probably would have accepted a completely different actor playing Tarkin set the week before Star Wars.
Anyway: the VFX work is great. It's not bad. I don't see how you could call it that. It's pretty damned amazing. But maybe the direction didn't help it as much as it could have.
So, here's the CG model for Princess Leia:

That work is pretty damned amazing. "But of course it looks good! It doesn't have to move. It just has to sit there and look like the still of Carrie Fisher from 1977 in the upper right!" Well, yeah. But even getting the fully CG model to so closely replicate that still to the point it's almost indistinguishable (and for a ton of people, it is, is still a pretty amazing feat.
But yeah, the problem is that once the mouth starts moving, the effect's believability starts to sufferfast:

Now, I don't know if that's a case of them not having enough time & money to get the de-aging down, or if it's a case of them having too much time and they just over-tweaked the thing until they wound up with a face that frame-by-frame looked right, but in motion read as very wrong. No clue. But I can tell you that somewhere between that model looking spot-on, and that model being made to say the word "Hope," something went awry.
And I think what went awry were two things, and both of them were directorial in nature, not technical.
(1) The decision to show her at all breaks continuity
This doesn't make much sense considering the whole point of her being there is because Rogue One appears to be a film that was made with one eye, at all times, on the notion that you're supposed to watch it directly before Star Wars. Yes, audiences could just accept the hard fact of this film having been made 40 years after the film it is immediately preceding, but everyone involved decided to try as best they could to make it match as seamlessly as possible.
Since that's the case: Deciding to show her at all breaks continuity. Because George Lucas obviously wanted to hide her identity until after she'd given the plans to Artoo. She's on the ship, but we don't know who she is yet. All the shots are selected carefully and arranged just so, in a way so Leia's "reveal" is meant to be the steely-eyed, determined young girl with a gun in her hand who isn't going to take any shit.
Now, the first time we see her is this:

Which brings us to (2) Leia is out of character
Now, not only are we seeing her, but the direction here doesn't make sense for either Rogue One, or Star Wars. Why is she so full of starry-eyed hope? How does that make sense for her character, especially at that moment? Immediately leaving the Battle of Scarif, and right before Vader personally snaps the neck of her captain and takes her hostage after getting shot, we get a moment of her doing this 100% idealistic, soft-focus, sadly happy reaction to getting the plans?
It doesn't make any sense, really. The emotion we're seeing Leia try to pull off there is an emotion Leia almost never shows in any of the films, and especially not in moments like that. Which might be helping with that uncanny valley vibe of the animation a lot (i.e. "why... why is she so happy here?") as well as making it harder to animate her face convincingly in the amount of time they had. If she's determined, or focused, or even slightly angry at what the Empire's just done, maybe that line plays better, and maybe that emotion is easier to essay in the few seconds she's onscreen.
It's not really a matter of the work being bad. The work is good. The way the VFX team was directed to use it sorta sabotaged 'em, I think. Same thing happened with Tarkin - that model's been posted in here already, and again - it's a great model. They put in a ton of work to make that effect believable, and most of the time, it shows.


But as per this IndieWire article, you realize that what they were being asked to do with the effect (and how they were asked to do it) sorta diminished the best possible applications of it: Tarkin looked perfect under specific lighting, but they didn't manipulate the lighting on the Death Star scenes in post to allow for that effect to work correctly. Henry's performance was great, but because his mouth movements weren't 100% like Cushing's were, they went in and hand-animated the mouth. Did they overwork it? Did adhering to 100% frame-by-frame fidelity to a dead man's movements (a fidelity maybe 0.0001% of the audience would even notice) cause uncanny valley instead of mitigating it? Who knows.
They probably coulda never showed Leia's face and just put some makeup on Guy Henry and called it a day, really. Maybe they shoulda. Guy Henry looks like Peter Cushing enough that it wouldn't have to be that weird fright-mask they slapped on for Episode III. And considering the film features a completely different actress playing a Mon Mothma set something like 3-4 years before Return of the Jedi, audiences probably would have accepted a completely different actor playing Tarkin set the week before Star Wars.
Anyway: the VFX work is great. It's not bad. I don't see how you could call it that. It's pretty damned amazing. But maybe the direction didn't help it as much as it could have.