Photorealistic Nudity of TV/Movie Characters

Prompted by this artwork (not safe for work): deslea.deviantart.com/art/Dark…

As I noted in the comments to that work, this one was an interesting one philosophically because it made me think about how explicit I am willing to get with these particular 3D characters, who bear a really strong, borderline-photorealistic likeness of the actor(s) who played them in the source fandoms. I would draw a distinction between 3D, and work that constitutes a strong likeness but is clearly not a photo-style work - so, for instance, highly realistic drawings and paintings. However, I don't know if that's a "fair" distinction to draw. It's a gut reaction, more than a reasoned one.

For me, I think one important factor here is whether I think the actors might find it uncomfortable to see these borderline-photorealistic depictions of themselves in these situations, and that's only an educated guess on my part, but short of asking them, that's the best we can do. I draw on their own body of work in thinking about this. Helen McCrory has gone nude quite a bit in her career, so I think my threshold for Narcissa would probably be quite high. Whereas Helena Bonham Carter, as far as I know, hasn't - her sex scene in Fight Club was reportedly completely CGI'd and her sex scene in Henry VIII was soft-focus in silhouette. (I don't know every work she's done, though). As for Christian Coulson, I have no idea at all.

What do you think? Are there any hard-and-fast rules about this, or is it case by case? Or do we say that everyone knows these are not, in fact, the actors posing, they've chosen to allow their likeness to be associated with characters that do different things than they would, and there are no rules? Does the hyper-realism of a well-executed 3D render put it into a different territory and call for different rules?