The pioneering moviemaker used the very latest camera technology to turn actors and actresses into fantasy beings in his alien love story - and he's particularly pleased with the way Saldana's character came out.
Cameron says, "Right from the beginning I said, 'She's got to have t**s... (and) I came up with this free-floating lion's mane-like array of feathers, and we strategically lit and angled shots to not draw attention to her breasts, but they're right there.
"The animation uses a a physics-based sim that takes into consideration gravity, air, movement and the momentum of her hair, her top."
And there's one scene in particular in which Saldana's character, Neytiri, reveals a nipple that will excite film fans when the film eventually hits DVD - because it was deemed too revealing for a PG-13 rated film.
The director tells Playboy magazine, "We had a shot in which Neytiri falls into a specific position, and because she is lit by orange firelight, it lights up the nipples.
"That was good except we're going for a PG-13 rating, so we wound up having to fix it.
"We'll have to put it on the special edition DVD; it will be a collector's item."