While Phil McNally was pursuing a master’s degree in furniture design at the Royal College of Art in London, he changed his name to Captain 3-D.
“I liked the idea of being Dr. 3-D at first, but it seemed too academic,” he says. “I wanted more of the superhero. You know, Captain America, Captain 3-D! It’s very juvenile.”
Born in Northern Ireland and raised in England, McNally saw 3-D for the first time at 14, when a friend brought a WWII-era stereoscope to school that contained black-and-white photographs of German soldiers and prison camps. “I still remember the shock of that moment of seeing a portal back in time,” McNally says. “And I remember being amazed to the point that I photocopied all the images and tried to make my own viewer.”
After his animated short “Pump-Action” played at an annual conference on computer graphics and interactive technology in 2000, McNally moved to the U.S. to work as an animator at Industrial Light and Magic on such projects as “The Hulk” and “War of the Worlds.” When Disney contacted the company to convert its 2-D “Chicken Little” into 3-D, Captain 3-D was there to save the day.
Since then, he’s served as DreamWorks’ stereoscopic supervisor on “Kung Fu Panda” as well as the upcoming “Monsters vs. Aliens,” “How to Train Your Dragon” and “Shrek Goes Fourth.” “People talk about 3-D being a gimmick, but the reality is, moviemaking is a gimmick,” he says. “If you really want to focus on stories, just write books or tell stories around a campfire.”
Pump it up: All 3-D films are shot with two cameras, one to record images for the right eye and the other for the left. “We have two ‘cameras’ in the CG world,” McNally says. “Ultimately, what it comes down to is how much the cameras are separated. You can imagine if they’re exactly on top of each other, it’s like having one eye so that everything is flat. And as you move the cameras apart, if it were a ball, it would get more and more and more round. So as we increase that interaxial separation, the 3-D literally fills up in volume.”
Invasion of personal space: In addition to controlling the volume of characters and objects, McNally must determine their placement -- whether they appear to be in the “personal space” in front of the screen or in “world space” behind the screen. “The technical term for that is ‘the zero parallax setting,’ ” he says. “We control it by how much we overlap the images. My right eye’s looking here, my left eye’s looking here, and my brain puts those together as a single object.”
The one place where the object can exist, he says, is at the point where the two lines of sight cross. “3-D happens in your brain. It doesn’t happen on the screen; it doesn’t happen in your eyes; it doesn’t happen in the camera. It only happens when your brain gets the two images.”
Advanced placement: For each film, McNally creates a depth script dictating the 3-D volume and placement for each scene.
“Placement is related to how you want the audience to relate to the characters,” he explains. “And so there’s a sequence in ‘Monsters vs. Aliens’ where Giant Susan is talking to her fiance on the rooftop, and it’s the breakup scene. His problem is that she’s this giant 50-foot woman now. And so that is staged specifically so that he’s in front of the screen toward us and she is more distant behind, because it helps the scale and it also helps us establish that the frame of the movie -- what we call the stereo window -- is like a divider between this conversation where she’s on that side and he’s on this side.”
Whoa, that’s deep: To avoid eye strain, McNally’s depth scripts confine the most extreme 3-D to certain scenes, such as the climactic battle in “Monsters vs. Aliens.” “Obviously, we want to ramp up this big event at the end of the movie with all this big action,” McNally says. “There’s a great shot where Susan’s diving off the top of an exploding platform with all the guys and she’s falling into this huge space. There are explosions, and there’s stuff flying out past us as well.”
Racking their brains: 2-D techniques such as the rack focus -- in which the focus is shifted between the background and foreground to direct the audience’s attention -- are not as effective in 3-D filmmaking. “In 3-D, if you just do a rack focus without anything else changing, half the audience will be left looking at someone who just went blurry because there’s a strong desire to look at what’s closest, and there’s less desire to look at what’s farther away,” McNally says.
“That’s probably hard-wired because if you’re walking in the jungle and something appears close to you, you want to quickly look and see what it is. And so, successful use of shallow focus in a 3-D movie is that it has to move in support of the composition. In ‘Monsters vs. Aliens,’ there are some really great rack-focus shots, but you probably won’t notice them because the focus is moving in support of what you’re already doing with your eyes.”