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"  Peter Jackson has always loved the magic of moviemaking. After watching the 1933 classic King Kong at age 9, he started shooting stop-motion films with his family&amp;#039;s Super 8 camera. Three years later, he carved up an old fur coat that belonged to his mother and used it to create a model of the great ape. In his early 20s, the budding director was baking latex molds in his mother&amp;#039;s oven to produce the prosthetic hands and heads for Bad Taste, the homemade horror flick that earned him a trip to Cannes in 1987. But the eclectic cast of characters in the Lord of the Rings trilogy truly put his powers of invention to the test. To make the wizard Gandalf appear a few feet taller than his onscreen colleagues, Jackson employed a number of tried-and-true cinematic tricks. In one scene, he used a custom-designed wooden cart to position Elijah Wood (Frodo) far to the right and a few feet behind Sir Ian McKellen (Gandalf) and recorded the action at an angle that made it look as if the two actors were seated side by side. In the Hobbit trilogy, Jackson&amp;#039;s latest tribute to the mythic Middle-earth world created by author J.R.R. Tolkien, such sleight of hand was not possible. &amp;quot;Once you shoot in 3D, it completely blows your cover,&amp;quot; he says. &amp;quot;Your forced-perspective tricks are naked to the audience. With 3D glasses on, they can see exactly how far away the characters are.&amp;quot; This left the director with only one alternative: To conjure a community peopled with hobbits and dwarves, he would have to resort to the cumbersome process of filming man and halfling separately and uniting them digitally in postproduction. Jackson had occasionally used that technique in TheLord of the Rings, but The Hobbit was filled with dialogue\u2014often two or three script pages in succession\u2014between Gandalf and his pint-size pals. &amp;quot;It&amp;#039;s very difficult for them to have a conversation that feels natural,&amp;quot; says Jackson, citing his early attempts to unite the wizard with hobbits. &amp;quot;We would have Ian do half the conversation and then Elijah would have to fill in the hole Ian had left him. It was a stilted way of doing it.&amp;quot;  So before filming began on The Hobbit, Jackson asked his team to come up with a better approach\u2014one that would allow him to direct every scene in real time. The answer arrived in the form of an innovative motion-control system. Instead of shooting the actors one at a time, the director placed them on two different sets\u201450 feet apart\u2014and recorded them with different cameras. The live, or master, rig was outfitted with encoders that measured the pan and tilt of the camera, the motion of the boom that held it aloft, and the speed and movement of the dolly beneath the whole setup. This data was crunched, scaled, and instantly relayed to a slave-rig camera on a green-screen set, allowing it to move on three axes in perfect harmony with the first. &amp;amp;gt;  In this way, Jackson could place the slave camera much closer to Gandalf and\u2014with the magic of software\u2014remove the green background and merge the images from the two sets so it appears as if the wizard towers above the dwarves. One challenge was to create a green-screen set that precisely mirrored the live set\u2014archway, walls, chandelier, etc. If Gandalf rested his hand on a green-screen table, it could not appear to float above the top of the table on the live set. To precisely position everything, the crew invented a device called the Pinger. Think of it as a laser-beam protractor: It measures distances and angles, allowing the crew to pinpoint the critical contact spots common to both sets. Once those spots were aligned, the live-set and slave-set cameras worked together to generate the proper perspective. The system included a monitor that supplied Jackson with a live composite of the two shots so he could watch the scene unfold. The actors on both sets used green tennis balls to locate their sightlines and hidden earpieces to follow the dialogue. In the system&amp;#039;s trial run, Gandalf pays a visit to Bilbo&amp;#039;s Bag End home with a company of dwarves clustered around him. In the course of the shot, he has to duck below an archway, bump his head on a chandelier, greet each character by name, lay the dining room table with forks and knives, and accept a cup of wine from a cohort. The live set was built to human scale. The table, the plates, the drinking cups were all of normal size since they would be filmed next to average-size actors. The items on the green-screen set were scaled down by 25 percent. In Gandalf&amp;#039;s hand, the wine cup looks tiny. But because the slave camera was placed closer to him, the cup and the hand both appear much larger on film. In fact, when the two images were combined, the cup looks exactly like those in the hands of the dwarves.  For the two shots to blend seamlessly, everything Gandalf interacted with had to be represented in some form. The scaled-down table and archway were green, the knives and forks looked like those on the live set\u2014only smaller. Because the wizard had to bump his head on the chandelier, it was scaled down and placed on the green-screen set. Green boxes indicated walls and corners to help McKellen visualize the geometry of the room. The cup of wine was presented to him on the end of a green stick at the very moment that an actor on the live set was handing a second glass to another green stick. &amp;quot;There was a lot of inventing going on,&amp;quot; says motion-control supervisor Alex Funke. &amp;quot;We were figuring out how to do stuff as we went along. It wasn&amp;#039;t just taming the software, it was finding the tricks that made the system fly, made it work convincingly.&amp;quot; Even with the Pinger, for example, the crew soon discovered that when you enlarge Gandalf to make the world look smaller, the floor seems to rise up too. This made for awkward compositions with McKellen floating above the ground or sinking down into it. To solve the problem, the crew built platforms for him to walk on. But since that proved to be far too time-consuming, the team came up with yet another innovation. In essence, Jackson&amp;#039;s technical wizards found a way to shift the whole world inside the brain of the motion-control system without it noticing the change. To grasp the complexity of that challenge, it helps to understand how the system&amp;#039;s coordinates were compiled. The lift and swing of the boom were measured by monitoring the rotation of gears affixed to the rig of the live camera. The dolly&amp;#039;s movements were measured by a skateboard wheel mounted on a spring-loaded spar beneath the chassis. After the data was collected, the motion-control system did the math, plotted the shot sequence on the three axes, and relayed this information to the slave camera in the form of sync pulses.       You can&amp;#039;t just offset the camera. If you do that, you&amp;#039;re completely disrupting the mathematics that make those Cartesian coordinates work. But you can fool the system. Thanks to an ingenious device called the Knob Box\u2014whose means of operation remains top secret\u2014Jackson and team could tweak by hand any slight miscalculations on the slave set without causing mayhem to the 3D effect. If the archway was out of line by a fraction of an inch, they could fiddle with the rig&amp;#039;s north\u2014south axis without upsetting the scene&amp;#039;s complex choreography. It took time to work out all those bugs. In fact, Jackson still jokes about the headaches he endured during the technology&amp;#039;s trial run. &amp;quot;It does represent the only time in my filmmaking career,&amp;quot; he says, &amp;quot;that I spent an entire day shooting a scene and didn&amp;#039;t get a single frame of film.&amp;quot; But everything went much smoother on day two. The crew wrapped up the shot before breaking for lunch. &amp;quot;At first, we were all quite daunted by [the technology],&amp;quot; lead actor Martin Freeman says. &amp;quot;I just thought, are these people mad? That will never work! And then I saw a cut and thought, yeah, it really does work. It works amazingly well.&amp;quot; These days the director likes to marvel at how the technology rescued him from having to preprogram the camera, which in turn allowed the operator to respond to the pace of the action. &amp;quot;That was one of the joys of it,&amp;quot; Jackson says. &amp;quot;You didn&amp;#039;t have to think about the trick anymore. If you wanted to crane, dolly, move in, move out, or have characters come in and out of the frame, designing the shot was just as it would be on a live-action set.&amp;quot; In the end, Jackson&amp;#039;s latest stab at movie magic is invisible, and that&amp;#039;s a good thing; it freed the actors to provide the drama. In the slave-motion control scenes, the director shot 10 to 12 takes\u2014and every one of them was fresh. 3D or Not 3D: More Hobbit Tech Trivia \u00B7 The film was shot at 48 frames per second\u2014twice the usual rate. The increase in resolution forced the actors to use wigs with real hair. \u00B7 At 48 fps Red cameras tend to mute color, so the set designers broke out their paintbrushes. &amp;quot;The trees look incredibly psychedelic,&amp;quot; director Peter Jackson says in the film&amp;#039;s video blog.  \u00B7 Artists Alan Lee and John Howe often worked side by side, one drawing in red, the other in blue, to create 3D concept sketches for Jackson.  \u00B7 The prop team created medieval weapons at four scales. Those weapons were often placed in the hands of diminutive doubles. "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/culture/movies/a8502/the-secrets-behind-the-hobbits-3d-wizardry-14851524/>