Who says dreams aren’t in 3D? If you’re filmmaker Robert Rodriguez—or, better yet, his son, Racer Max—they certainly are. For only a father can make his son’s dreams come true.

It was Racer who came up with the idea for his dad’s latest 3D kids tale, The Adventures of Shark Boy & Lava Girl in 3D. The story, based on a dream of the second oldest of four Rodriguez lads, is about a young boy—coincidentally named Max—with an active imagination. A loner who takes a lot of teasing at school, his life is rounded out by two imaginary friends, Shark Boy and Lava Girl, whom Max truly believes in. The pair call on him one day to help save their home planet, Planet Drool.

The film is the second 3D kids feature for Rodriguez, the other being 2003’s Spy Kids 3D: Game Over, the third film in his Spy Kids series. Both films are presented in anaglyph 3D, for which theatergoers separate red and cyan-tinged left and right images using red and cyan-tinted throwaway (or keep, if they prefer) glasses given out at the theater.

Anaglyph is a type of stereo 3D image created by combining two video streams taken approximately 2.5 inches apart, typically the distance between human eyes. The red color field of the left video stream is combined with that of the right stream in such a way as to create the illusion of depth. These images may then be viewed with anaglyph glasses, which use color filters to moderate the light reaching each eye to create the illusion of a three-dimensional image. The benefit of anaglyph 3D over polarized 3D, common in IMAX films, is that theaters don't have to install special projection equipment or screens to run films in anaglyph 3D.

Spy Kids 3D (SK3D) was shot using a single “beam-splitter”-type 3D camera system, the Reality Camera System, from Sun Valley, Calif.-based Pace Technologies, which developed the technology under a joint venture with filmmaker James Cameron. Commissioned and built for the underwater 3D IMAX documentary Ghosts of the Abyss, RCS combines two Sony high-definition 24p cameras (HDW-F950s) and their Fujinon zoom lenses into a single unit, incorporating a motion controller to provide simultaneous control for both lenses and on-camera convergence.

Instead of placing the two cameras side by side, the beam splitter 3D rig of the Reality Camera System positions one camera above the other, looking into a half-silvered mirror placed at 45 degrees to the axis of the direct-facing camera (which usually records the left image). A portion of the light passes directly through the mirror to enter the direct-facing camera, while the rest bounces off the mirror into the down-facing camera, which captures the right-hand image.

Though more cumbersome than two cameras placed side by side, the beam splitter arrangement allows the distance between the two lens axes, known as the “interocular” distance, to be narrowed below the normal 2.5-inch interocular, a number based on the average distance between the human eyes. “With a side-by-side arrangement, the optical blocks of the cameras prevent the interocular from getting any smaller than that,” explains Pace Technologies president Vince Pace. “Sometimes you want to reduce the interocular—for instance, if you want to get close up to an actor’s face and avoid any elongation of the facial features that might occur if the lenses were further apart.” In RCS, the convergence can be driven independently or slaved to focus, iris and zoom controls.

For Shark Boy, Rodriguez decided to go with a two-camera setup, requiring an A- and a B-rig. Pace supplied one complete rig, with two F950s, and a second, minus the cameras, allowing Rodriguez to use the pair of F950s he’d acquired for shooting Sin City. All four cameras were fitted with Sony’s HKC-T950 HD CCD block adapter, which allows the CCD block of the F950 to be extended from the camera body by up to 10m, or up to 50m with a cable. The adapter allows the imaging assembly to be placed in areas where a full-size camera wouldn't fit, enabling more creative camera shooting angles. The system recorded at 4:4:4 to Sony SR-1 portable HD decks, also veterans of Sin City.

Along with new cameras came updated 3D rigs. “For this film, the decision was made to take the system to the next level as far as refinement and control,” says Pace. Rodriguez sent Camera Operator Jimmy Lindsey and 1st AD Sebastian Vega to meet with Pace and engineer Patrick Campbell. “Sebastian and I have a great working relationship with Vince and Patrick,” says Lindsey. “We’re able to go to them and ask for modifications that need to be made on a very challenging timeline. Design changes come about simply from using a system, running into a problem and coming up with possible solutions. It’s nice to work with Vince because he really understands 3D and is never afraid to push the envelope.”

First and foremost was a redesigned frame with increased rigidity and stability, which helped keep the various control parameters in adjustment. The rig’s mirror was outfitted with a cam system to allow for simple adjustment at the turn of a dial. “Fixing vertical misalignments is critical for 3D,” says Vega, who acted as both stereographer and convergence puller on the project. “Alignment can go out on a multitude of axes, and any one of them can negatively affect the 3D or even ruin it completely. Misalignments between the two lenses, either in focus or, worse, zoom, can really mess things up—the latter like wearing a binocular on one eye. Your eyes are used to horizontal misalignment, which they adjust for by converging, more or less. But you don’t have one eye pointing up and one pointing down [to correct for vertical misalignment], and so we need to be able to correct any vertical misalignment with the camera. Now we can, easily, on the fly.”

Pace improved the precision of the control system, providing a faster, more finite response. "What makes this camera unique is the combination of leading-edge electronics and mechanical design coupled with the latest in Sony camera technology," Pace explains. "The beam splitter is made up of a nine-channel motion controller to operate zoom, focus, iris, convergence and interocular functions. All control functions are then mapped on the metadata stream, embedded using Evertz VANC equipment." In addition, Pace added a laser device to the lens mount that assists in aligning the cameras, particularly important when attempting to aim the down-pointed lens, as it bounces off the half-silvered mirror.

For lenses, Lindsey stuck with a favorite: Fujinon zooms. “We’re big believers in using zoom lenses with high definition,” he explains. “Back focus is still a major technical obstacle. HD cameras generate heat, which means back focus shifts as each new lens acclimates. Zoom lenses give us many focal lengths without optic changes that would require additional time on set for back focusing.”

On Spy Kids 3D, the team used Fujinon 5-50mm zooms, but for Shark Boy, Fuji’s 5.2mm-52mm (HA 10x5.2BE) lenses were used. “The 10x5.2s have a better minimum focus, which was very important because we’re often putting actors very near the matte box. Fujinon took care to ensure the two lenses matched perfectly, which is critical for good 3D. "Chuck Lee and everyone at Fujinon really understand optics, certainly for the high-def world. Things wouldn’t go smoothly without technical assistance.”

Better 3D

Rodriguez and his crew, now “old hands” at 3D cinematography, built on their experience on Spy Kids 3D to improve the quality of the 3D experience for the Shark Boy audience. “Between myself, Sebastian, [Visual Effects Producer] Keefe Boerner and our gaffer, John “Fester” Sandau, it’s now a well oiled machine,” says Lindsey.

Like most 3D movies, Shark Boy has plenty of in-your-face shots. “It’s a kids’ 3D movie, so there are lots of things that get stuck into the lens and end up in the audience's lap,” says Vega. “But you have to be careful. You’re tricking the eyes. Every time you put a 3D image in a movie, it’s a completely optical illusion. And if you push the illusion too far, it breaks down.”

“Robert has a vast knowledge of visual effects; he’s done a lot,” says Lindsey. “He never asks for things he’s not willing to deal with on the other end [in post].” Vega agrees. “He relies to some extent on the technical expertise of others, but he learns and masters technology that’s new to him very, very quickly. He gets up to speed quickly and knows what he wants, and he has a pretty good handle on what can be accomplished and how far he can stretch the medium.”

Shots would begin with concept design meetings with Boerner, Previsualization Supervisor Chris Olivia and Concept Designer Alex Toader. “There isn’t much of a script at that point,” Olivia says. “Robert will just give us the basic structure and explain the characters and the scene. Then we just cut loose and come up with cool visuals and get them to work in the context of the story he’s trying to tell in that sequence. We’re given a lot of creative freedom. Robert trusts our judgment. He knows that we know him and what he likes.”

The result, for the most part, was animatics for each shot, though it wasn’t long before that step had to be passed. “We didn’t end up having time to create full animations before they started shooting,” says Olivia. Instead, the animatic team developed stills to represent each angle and each shot, whose camera angle and other information would be matched on set.

One useful tool was EncodaCam, a camera visualization system created by General Lift and Brainstorm. The real-time virtual set service gives film crews the ability to see all they will be filming, both foreground and background on a greenscreen stage—essentially a form of on-set compositing. Since the majority of the film was shot with actors in front of a greenscreen, says Olivia, “EncodaCam enabled them to put our backgrounds into the shot, with the actor keyed out of the green background, and view the shot with a CG environment, giving them an idea what the completed shot would look like.” Adds Lindsey, “It allowed us to set up shots quickly and judge foreground and background elements as we would if we were shooting on location rather than on greenscreen.”

Sometimes, however, Rodriguez would simply improvise. “The fun part about working with Robert is that the process isn’t set in stone,” notes Lindsey. “Sometimes he has a very specific shot in mind that he wants done a certain way. Other times he just has an idea and wants to see what we can do on the fly.” Animatics can go right out the window. “Sometimes he’ll just say, ‘Make it cool.’ I’ll get on the crane and we’ll find the shot that works best for the sequence.”

Lindsey and Vega could also easily confer with Boerne, whose department was handily located just upstairs from the soundstage at Rodriguez’s Troublemaker Studios complex. In addition, 2D Supervisor Eric Pham could check their work, to make certain 3D shots were behaving as planned. “I have a direct link to the stage and the tape deck,” he explains. “I can actually pull the signal in while they’re shooting and do some tests and give them immediate feedback.”

As for improvements to the quality of their 3D shots, Troublemaker invited Pete Routhier of Montreal-based 3D projection company Sensio, with whom the studio had consulted on the home video release of SK3D, to offer some training. “They had noticed some areas where we weren’t following basic rules as far as comfort level for the eyes,” explains Visual Effects Producer Keefe Boerner. “They provided a computerized calculator in which we could enter lens focal length, interocular distance and a convergence point, and it would provide the viewable 3D field,” says Vega. “Just as with a regular camera, where there’s a field range in which something is perceived to be in focus, there’s a similar theory in stereography as to what the audience will perceive as a comfortable viewing experience in 3D. This calculator helped provide a framework for deciding how to set the camera, instead of by feel, as we had done before.” Boerne also hired Routhier to train a number of the visual effects houses that worked on the film.

To prepare shots on set, Lindsey lined up the camera using the left eye image (since the right eye camera, receiving a reflected image off the rig’s mirror, is reversed). “Then I have a mirror box up at the camera that allows me to look at live 3D with polarized glasses. Sebastian has a pair of monitors he views in 3D as well, and we talk on the radio about camera adjustments to improve the 3D image.”

One of the things the team had learned about the new Pace system, which included the ability to adjust both convergence and interocular on the fly, was to avoid doing just that. “Even though visual effects is getting some metadata,” explains Vega, “it’s better to let them adjust convergence in post rather than us doing it in camera. It allows them more control in completing the shot and the backgrounds. Otherwise, if they want to change convergence or interocular pulls that we’ve done in camera, it’s virtually impossible.”

Vega took advantage of postproduction’s ability to change convergence—or use a completely different setting—by creating a “cheat.” “Because the background isn’t built yet, we can exaggerate the convergence on foreground objects, such as actors, to produce more in-your-face 3D. Then the visual effects house can use a different convergence setting for the background elements. It’s as if space is curved instead of straight.” Adds Lindsey, “Sebastian is now able to decide which rules to break to make the 3D as good as it can be.”

Another lesson learned dealt with lighting. “Robert likes a lot of back light. If you have something with a hard edge light or strong highlight, and the image is fairly diverged [such as an object in the background, for example], it will tend to create eye strain.” During one scene, shot on a practical classroom set, the metal rim around the blackboard in the background posed just such a problem because the lens axes were set to converge on the actor in the foreground. “In order to make the shot work, we had to reduce the contrast by dulling the object down or diffusing the light. We would advise Robert of possible problems and he would either tone it down or not, depending on the aesthetic he wanted.”

With most of the film shot on greenscreen, a massive 860 visual effects shots had to be produced over a two-month period. While Troublemaker Studios accomplished some 120 shots, the rest were farmed out to nine other VFX houses, including Hybride Technologies in Quebec, CafeFX in Santa Maria, Calif., and The Orphanage in San Francisco, all of whom Boerne had worked with on Sin City. Other companies—including R!OT, Industrial Light + Magic and Tippett Studio—made up the balance.

Once completed and approved by Rodriguez, the visual effects shots are sent to Post Logic Studios in Hollywood for color timing. Upon arrival, Editor Matt Johnson loads them on a Quantel iQ system and edits and conforms the shots into reels, left and right. The reels (a total of six for Shark Boy) are then color timed by Colorist John Persichetti, a veteran of several Rodriguez films, including SK3D.

Working on a da Vinci 2K Plus color corrector, which accesses the files from a DVS file server, Persichetti performs his color timing on the left eye image, parameters of which are then simply applied identically to the right eye file. “In 3D, all your work is doubled,” he says. “We had done some research, along with Hybride Technologies, and determined that whatever you do to one eye must be done identically to the other; otherwise, it doesn’t work.”

Color timing for an anaglyph film can’t involve any “fancy color correction,” he says. “A good deal of what I do is balancing shots between the different vendors to make sure they match.” Because red and cyan/blue are the colors used for filtering to allow 3D to be viewed, the colorist's palette is limited to colors that won’t be affected by the anaglyph filtering: yellows, greens and purple.

The imagery, once in the 3D world, is, in fact, fairly flat in color. “Once the 3D glasses go on, color pretty much goes out the window,” says Persichetti. “You can get away with a lot more, color-wise, because you’re almost completely in an imaginary visual effects world. Also, kids will accept a lesser degree of real color than adults will. They’re more into what’s going on with the 3D. Additionally, color gets sacrificed for viewer comfort.”

Once color timing is completed, the aforementioned Sensio company will apply the anaglyph filtering, removing red from one eye and cyan from the other, and then combine the two images into a composite single image. The scenes are then checked to make certain overall color timing and the anaglyph application are correct. “The effects houses won’t have seen the shots on a big screen; they’re working on CRT. So we check to make sure everything’s working,” says Persichetti. If a change needs to be made, some can be made by Post Logic, either by Persichetti using his color corrector or by Johnson, who can make some slight convergence or interocular corrections, if needed. Failing that, the visual effects house will correct the shot."

Because the film was shot with dual HD cameras, Post Logic was able to prepare a 2D version of the film from the same material as the 3D version. The 2D version is released to theatrical markets that won’t be showing the film in 3D and is included on the DVD release (along with the 3D version). The 2D version, of course, can include colors that can’t be used in the red/cyan anaglyph world (i.e., reds and blues that would otherwise be eliminated from one eye when viewing with anaglyph glasses). Yet another pass is made for the two DVD versions, since CRT color space is different than that of projection color space.

An interesting side note regarding the anaglyph glasses: In theaters, youngsters are provided either Shark Boy anaglyph glasses or, for the young ladies, more feminine Lava Girl glasses. Lest a ruckus result from a theater running out of Shark Boy glasses and a young boy is given pink Lava Girl ones, Rodriguez, the father of four boys, has a solution built into the film. In the scene in which Max and Shark Boy and Lava Girl first enter the 3D world by putting on their own 3D goggles (the audience is instructed to do the same), Max is handed pink “Lava Girl” glasses. “Do you have another pair of boy goggles?” he asks. It is explained to him that both types of glasses produce the same result and not to worry about it.

Rodriguez keeps a family atmosphere at his studio. “His kids are there all the time,” notes Boerner. “He often has them watch a film he’s working on to get their feedback. Each of them, in fact, is in the movie. It’s actually credited as ‘A Rodriguez Family Movie.’” Recalls Lindsey, “It’s fun to see the kids having so much fun making movies. You can tell they’re having the time of their lives. And if you’re going to make movies for kids, you should have fun doing it. 'Cause if you don’t, they’re probably not going to have fun watching it.”

It appears the children aren’t the only kids enjoying themselves. “We all have a good time," says Boerner. "From a technical standpoint, Sebastian and I have access to the coolest toys on the planet. We get to play with the best stuff because Robert demands the best camera and effects equipment. And we get to play with it. That’s a lot of fun.”