Warning: video and photos may be considered NSFW.

Many of us first became aware of this practice last month, during the final episode of the fifth season of Game of Thrones. In a deeply compelling scene, Cersei Lannister (Lena Headey) is forced to atone for her sins with a humiliating nude walk through the center of town, during which she’s both verbally and physically assaulted by an angry mob of townspeople. It’s a shocking, and at times painful, scene to watch — but it doesn’t actually feature Lena Headey’s body. Over the course of two days, the scene was shot twice: once with a clothed Headey, and once with a nude body double, with the two takes merged in post-production to create the illusion of a naked Headey.

The practice of using CGI to create the illusion of nudity dates back at least five years, when the Machete special effects team digitally removed Jessica Alba’s underwear to create the appearance of nudity. The Machete scene — which initially seemed to contradict Alba’s earlier statement that she’d never do a nude scene — caused a minor stir among fans and media, who began to debate whether Alba had "tricked" audiences with her CGI striptease — a notion that often seems to come up any time an actress has the audacity to reserve glimpses of her naked body to a limited audience. In the years since, the practice has appeared in a number of other films, including The Change-Up, Nurse 3D, and Very Good Girls — and, according to sources working in digital effects, a number of productions we don’t even know about. As digital effects become a more routine part of film production, it’s become increasingly easy — and affordable — to use them to enhance or alter a nude scene; all signs point to this practice being here to stay.

But even as prices of digital effects drop, they’re still more costly than just shooting a performer nude. So why are we seeing such a dramatic uptick in altered nudity? In the years since Machete, numerous theories have been floated. Some have suggested it’s a way to get around nudity banning clauses in performers' contracts, while others have seen it as a way for performers to have their cake and eat it too, receiving kudos for risks they didn’t actually undertake.

According to one CGI editor, who requested anonymity, the truth of the matter is far simpler: directors offer the CGI option to make performers as comfortable as possible, and, in turn, to create the best scene possible. A performer who feels awkward stripping down in front of not just co-stars and a director, but a crew full of shooters, PAs, film assistants, and anyone else who might be present on set that day, is unlikely to turn in a stellar performance. Far better to shoot them in a more comfortable set up, and digitally add in the more risqué aspects of the scene after.

Indeed, this explanation parallels Headey’s own for her choice to go CGI in her scene. When asked by reporters why she opted not to shoot the full scene herself, Headey cited the ability to focus on the emotions of the scene, rather than the emotional and physical discomfort of actually parading naked, not merely in front of a few co-stars and crew, but a massive crowd of extras performing incredible hostility. Headey’s filmography would suggest she’s hardly a prude, with nude appearances in a number of projects including Aberdeen, The Broken, and this year’s Zipper; so it feels hard to fault her for opting to go the digital route in this obviously grueling scene. (Interestingly, it was Headey’s previous nude work that made the walk of shame’s CGI easier to spot, as fans compared the Game of Thrones scene to her existing scenes.)

An enhanced ability to focus on their performance isn’t the only reason performers turn to CGI, however. For some, the same pressure to appear physically perfect that’s caused Photoshop to run rampant in magazine offices has led to more widespread use of CGI as a kind of foundation garment. The CGI editor I spoke with described this as the "supermodel effect," where the ever presence of digitally altered bodies leads us to believe that these CGI creations are a standard we must all adhere to. "It’s like pornography, where younger people see it, and it’s all they know" — even though the sex depicted in pornography is unlikely to bear much resemblance to what many of us do at home. (Given the lower budgets of adult entertainment, on the other hand, the bodies we see in pornography are far less likely to be retouched.)

With beauty work becoming a more regular part of post-production, it’s not much more effort to offer performers digital breast and butt lifts, or to swap out their nipples for a whole new look. Ultimately, digital effects allow filmmakers to craft a more perfect nude scene — whether by improving a cast member’s performance or by erasing their physical flaws — and for many, the temptation of digital nudity is hard to resist; especially if it represents a small addition to an already sizable CGI budget.

Jim McBride isn’t thrilled with the turn toward CGI. The founder of Mr. Skin, a website devoted to tracking celebrity nude scenes, McBride has been maintaining an exhaustive list of celebrity nude scenes since his site launched in August 1999 (Disclosure: The parent company of MrSkin.com purchased Fleshbot.com from me in early 2014). In addition to providing detailed lists of when, where, and how female celebrities have shed their clothes on camera, the site also keeps viewers abreast of when those scenes feature the actress’s actual body — and when we’ve been served up a body double instead. Though Mr. Skin’s posts are celebratory in tone, equally excited to see any actress disrobe, regardless of her body type or age, the site has spawned numerous copycats and clones, many of whom view on-camera nudity through a more critical lens (which, it should be noted, might very well fuel some of the insecurity that leads performers to pursue some CGI assistance).

"We would prefer that the actress did her own nude scenes, that would be our number one choice," he says. But he also doesn’t see digitally enhanced nude scenes as anything new: "It’s no different than when they were doing body doubles through the years… Not every movie actress is going to want to do a nude scene. Maybe something’s wrong with her body at the time, or maybe some other actress had a better butt, so they use a body double. There’ve always been body doubles, there’ve always been scenes where there was nudity and it wasn’t the actress you thought it was. This has been going on forever."

What’s different now, however, is that CGI makes those body doubles more difficult to detect. In previous eras, a nude shot that featured body as well as face was very likely to be real; nowadays, it’s harder to guarantee that that’s actually the case. For McBride, it was 2011’s The Change-Up — which featured "nude" scenes of both Leslie Mann and Olivia Wilde — that made the promise (or, depending on your view, danger) of CGI nudity all too clear.

"[Leslie Mann] did this incredible topless scene, but it was all done in post-production. And she admitted it on Jimmy Kimmel after the fact. I remember seeing that nude scene… and finding out later that it wasn’t her, and thinking, ‘Uh oh, it’s going to be a lot tougher to know if it’s an actress or not.'"

McBride remains confident that — whether it’s through DVD extras, interviews, or leaks to the press — the truth will always come out. But others aren’t so sure. When asked what percentage of nude scenes are faked, the CGI editor I spoke with wouldn’t even hazard a guess. "A lot of times those things are kept really low key," he says. "There’s a lot of beauty work in a lot of movies… but in terms of nudity, I don’t know." Studios that are paying editors a good deal of money to create the illusion of nude scenes have a lot of incentive to keep their work under wraps: as my source put it, "the best visual effects are the ones you don’t see."

That tendency toward secrecy can fuel an audience’s sense that they’re being subjected to trickery — or, when the truth comes out about a digitally altered scene, that they’ve been the victims of nudity-filled bait and switch. In the aftermath of the Game of Thrones finale, none other than Howard Stern felt compelled to speak out about how the scene had betrayed him. As McBride describes Stern’s reaction, "It was such a let down when he found out, when they went on our website and we talked about how it wasn’t Lena Headey… He was really upset about it. He felt cheated, he felt that, ‘Wow, I’ve invested five seasons in this show, I think Lena Headey’s beautiful, and she finally did this amazing nude scene...’ and then he found out it wasn’t her, and he felt bad."

For McBride, Stern’s reaction is a great example of the betrayal fans can feel when they’re fooled by a well-done body double or CGI. But for others, the notion that actresses might owe audiences their nudity as thanks for their viewership can be an uncomfortable one, particularly in a world where a similar notion has sparked massive violations of privacy, like last summer’s Celebgate. It’s hard to ignore the fact that much of the outrage around faked nudity doubles as outrage that a woman has not given up the goods. It can be hard to even track down discussions of male celebrities’ nude scenes, period; and high-profile instances of faked nudity — like Mark Wahlberg’s prosthetic penis in Boogie Nights — tend to be greeted with humor rather than anger.

But perhaps it’s possible to read this reaction as something more than just a churlish demand that actresses show us their boobs. As consumers of modern media, we’re frequently forced to suspend our disbelief: to accept Zoe Saldana as a green-skinned alien, or a de-aged Michael Douglas as the genuine article, or that King’s Cross Station has a magic, hidden platform through which child wizards access a secret train. Up until now, nude scenes — which have been hard to seamlessly fake for so long — have offered an oasis of authenticity in a landscape of pretend. Whatever character an actor is playing, whatever fantasy they’re creating, when their clothes have come off, we’ve been offered a genuine moment of intimacy with another human being. As digital effects erect one more barrier between us, we’re forced once again to confront the fact that — no matter how much we love them, no matter how much they’ve impacted us — the stories we watch played out on screens before us aren’t actually real.

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