An Interview with...
Scott Johnston - Artistic Coordinator
for The Iron Giant

Scott F. Johnston joined Walt Disney Feature Animation in 1989 during the production of  The Little Mermaid. He continued his work with Disney on other films, including  The Prince and the Pauper (1990), The Rescuers Down Under (1990), Aladdin (1992), and was the principle designer of the ballroom sequence in Beauty and the Beast (1991).  He also did work on  The Lion King (1994),  where he oversaw the development and producton of all the 3D computer-generated effects, including the climatic wildebeest stampede that kills young Simba's father, Mufasa.  In 1997 Johnston founded his own studio, Fleeting Image Animation, Inc.  to develop and produce animation, integrating traditional and computer generated techniques.

"My involvement with The Iron Giant started in early 1997. Max Howard, then President of Warner Bros. Feature Animation, and Producer Allison Abbate were assembling the team for the show and thought I might be able to help with the challenge of bringing the director's vision to the screen." - Scott Johnston


Animation Artist:  What were your job duties as the Artistic Coordinator for The Iron Giant?

Scott Johnston:   Director Brad Bird and Art Director Alan Bodner would say what they wanted, and I would work with the artistic staff and production management to figure out how to accomplish it.  As the production pragmatist, I worked with management to weigh creative possibilities against resource limitations (budget, time... the usual suspects) and then suggest alternate ways of achieving as much of what we wanted as possible.  I often had to translate semi-abstract ideas into a coherent sequence of steps for the crew. I'd take care of the details, freeing Brad to focus on the performances.I tried to keep "the big picture" in mind.  Artists often work on very specific pieces of the puzzle; explaining the broader context of a problem would often help solve it.

Animation Artist: What elements of The Iron Giant contained Computer Graphics Imagery?  Also, what program did you use for the CGI?

Scott Johnston:  The Giant and an assortment of animating props--tanks, planes, trucks, and bikes--were done in CGI. In addition, artists created and modified artwork digitally for a wide array of effects.  Allen Foster and his crew did an exceptional job of integrating the traditional and digital effects work.  The majority of the CG work was done with Alias|Wavefront's Maya software package, with many in-house enhancements.  The CG levels were rendered with a modified version of Pixar's RenderMan and transferred into Cambridge Animation's Animo alongside the scanned pencil animation and painted BG's. We also used Alias' older PowerAnimator, Avid's Elastic Reality, Adobe's Photoshop plus a smattering of other programs here and there.

Animation Artist: You did a lot of CGI work for Disney's The Lion King. How do the two films (The Lion King and The Iron Giant) differ in the area of CGI and what aspects of your experience with The Lion King helped in your work with The Iron Giant?

Scott Johnston:  CGI was used throughout The Lion King, but the focus of the CG work involved the wildebeest stampede, which only takes about two and a half minutes of screen time.  While the behavior of the animals in the stampede needed to be believable, the range of acting and emotions never approached the complexity of the Giant. The Giant appears in much more of the film, and the animators needed to make him act with much more subtlety.  The appearance of the wildebeests had to blend seamlessly with the environment and traditional characters so the emotion of the sequence would work without a jarring alien presence. The Giant IS an alien in Rockwell. He needed to be a believable character, but the villain decries him as an outsider — something that doesn't belong in the human world.  He's a fifty foot-high metal character. He can't help being "different."

Animation Artist: Please describe for us a typical day in the life of Scott Johnston as it relates to your work with The Iron Giant.

Scott Johnston:   My schedule changed dramatically during production. Early on, we spent a lot of time planning the design of the character, building tools that we would need, creating workbooks for the sequences and trying to ascertain what we could and couldn't do. Later, a lot of time was spent adapting to the changes that inevitably occur as a movie starts coming together. The crew worked hard to give Brad what he wanted--and then some, but as with any project of this scale, the creators' original intentions can get lost in pages of notes and changes. I often had to help clarify these situations. If something was completely unknown, I'd ask Brad, or make something up—and apologize later if it was wrong. Solving problems often just amounted to understanding them and bringing the right people together: knowing who has the answer can be more useful than knowing the answer. Some days I acted more like a therapist. Artists usually know how to solve the problems that come up in the course of their work, but they may need to bounce the idea around or get someone to help them organize their thoughts. We also had to deal with the whims of technology and had a crew of engineers continuously improving an overburdened system.

Animation Artist: How did you successfully bring together the classic animation look with CGI in The Iron Giant so that it had the right look?

Scott Johnston:   By working with a great team of people. There are four principle areas that need to be addressed to integrate CG effectively into traditional animation:

The scale and shape of the characters and props had to be in the same style as the drawn elements in the film. Mark Whiting and Steve Markowski did the majority of the design work on the Giant, with additional comments and suggestions from Joe Johnston. Turning those sketches into a working 3D model required patience and the ability to adapt the design to make it animatable. Hiroki Itokazu not only built all the different versions of the Giant, but also all the tanks, trucks, cars and other 3D objects and props in the film. Most films have a staff of people building models. This guy is amazing!

Most CG is shot through an "ideal" camera, which is like a live action lens. As the camera moves, everything continually adjusts in perspective. In traditional animation, multiplane moves can create a great illusion of depth, but the perspective on individual background elements doesn't change while the animation camera is moving. The vanishing points are fixed on the layouts, and the artists often break the rules of perspective to accommodate the staging. For The Iron Giant, CG animation was shot with cameras that mimicked the animation cameras used in the rest of the film. A moving 3D camera quickly reveals the CG nature of a shot, so we used it sparingly and only for conscious dramatic effect.  Tad Gielow was the CGI supervisor for the film. His crew of Technical Director's (TD's) included both developers, who wrote the underlying code, and designers, who orchestrated the scenes, worked with the animators, and pushed the tools to their limits. In addition to managing the group, Tad added tools to Maya to imitate a traditional animation camera stand, allowing motion data to be shared between Maya and Animo.

CG is usually shot on ones because it is very easy for a machine to inbetween everything. Traditional, drawn animation is shot on ones and twos, because a movement on twos evokes a different feeling that may be more appropriate for some actions. We used both ones and twos on the Giant. The scale of the Giant caused special problems: a "small" motion for him often spanned large areas of the screen, and resulted in too much strobing when it was shot on twos.  Senior developer Mike Meckler engineered the infrastructure for writing extensions to the software packages we used and developed the controls within Maya that made Hiroki's models work for the animators. Senior designer Teddy Yang gave valuable feedback to the developers, and resolved issues and solved problems for the animators and designers.

Getting CG to match the drawn, scanned, inked and painted style of the traditional characters and effects is a difficult process. We simplified the color design of the character, using basic areas of light and dark and made minimal use of tones to add "shading." This technique is often used to give a character depth, and ours already had plenty. The Giant's color palette was chosen to give us the most flexibility in integrating him into the film. His dominant color is a neutral gray, which has a tendency to reflect the colors in his surroundings. Outdoors at night, his tone cools to be closer to the sky. Inside the barn, he warms to the incandescent amber of the wood and hay. His color constantly shifts with his mood and the environment.  A lot of work went into developing the rendering pipeline used for the Giant. Andy King started things off by getting the scenes out of Maya and into RenderMan. Brian Gardner built the shader and back-end of RenderMan to create the ink and paint images, which included detecting the inking lines and rendering them with subtle imperfections to match the scanned pencil lines from our traditional artists. The most novel aspect of the Giant's rendering was that the artwork was delivered to the Color Model department in the same fashion as the drawn elements. Rather than rerender each scene as the color palettes changed, Aaron Thompson and Babak Forutanpour wrote a tool to convert the rendered artwork directly into the format used by Animo, which allows color palette changes after artwork has been inked and painted. Brett Achorn and Rhonda Hicks made these tools work for all the CG elements in the film. The Giant was color-styled uniquely in each scene and balanced with all  the other elements.

Animation Artist: How difficult was it to animate expressions on the Iron Giant without losing the Giant's appearance of being an all-metal robot?

Scott Johnston:   One of the reasons the Giant was animated in CG was to prevent him from having the malleable look of a traditionally animated character. A series of illustrations by Mark Whiting proved that streamlined shapes could be used in a variety of positions to express the necessary range of emotions. Traditional animators often use broadly caricatured eyebrows to indicate facial expressions. We knew this wouldn't work on our Giant because eyebrows would look like large refrigerator magnets sliding around on his face. We wanted the logic of the Giant's design to be as evident as possible—Why would anyone build a giant with eyebrows—other than for expressive reasons?  Instead we concentrated on the varied illumination within the eyes and flexibility in the eyelids. The animators could control where the giant looked, and the dilation of an 'iris' and 'pupil'. Because of his height, we spend a lot of time looking up at the Giant. Not only did the expressions have to work without making him seem too elastic, they had to work from some odd camera angles.

Animation Artist: What was your biggest challenge with The Iron Giant and how did you solve that challenge?

Scott Johnston:   The scale of the elements in this movie was a constant challenge. The Giant's very, very tall, and we shot the movie in Cinemascope, so the screen is very, very wide. This makes his status as an outsider immediately apparent: he literally doesn't fit in the world. These scale constraints made it difficult to establish compositions that conveyed story points effectively and gave the animators freedom to act. Establishing the relationship between the CG stage for the Giant and the perspective on the layouts could be awkward, and often required animator 'cheats' that look okay on screen, but aren't literally possible. Traditional animators do this all the time. Because the Giant is so large, a close-up of him is invariably a long shot of anyone else in the scene. These scale issues also complicated the layout and background processes.

Animation Artist: A lot of our readers do CGI work and would love to know what steps they would have to take to be able to work on a movie like The Iron Giant.  What tips can you give to these aspiring artists?

Scott Johnston:  Draw. The stronger your traditional background, the better you will be with CG tools. Software changes all the time, but animation fundamentals—timing, staging, acting—will outlast any new software release. At the beginning of the show, we ran a training program on the CG tools for the traditional animators. Some of the best animation in the film was done by animators with no prior CG experience, who learned how to use the tools and were able to animate both the Giant and Hogarth in their scenes. A great example of this is a sequence shortly after Hogarth brings the giant home called 'Hand under foot' that Richie Baneham animated. Study life, not film. I learned this one from Brad. It's important to understand film and how problems have been solved in the past, but it's more important to see and interpret things yourself. You have to be able to put your own personality into your work. Animation becomes derivative and uninteresting if every scene and gag is a quotation from another film.

Animation Artist: As you are well aware, The Iron Giant has received rave reviews everywhere.  What, in your opinion, makes the finished product such a success?

Scott Johnston:   Story, story, story. We've heard it before, we'll hear it again. While the specifics of the story were flexible and evolved over time, we knew the main themes at the outset and aimed at those goals. What makes a movie a success is how that story is told. The Iron Giant is a fairly simple story, but is told in an appealing way. Brad is a very charismatic director, and I think we got a lot of that quality into the picture. We come to care about the Giant because Hogarth cares about him. That empathy is mixed with nostalgia--we remember when an adventure could be found in our own back yard.

Animation Artist: Now that your work with The Iron Giant is finished, what's next?

I'm taking a little time off to work on some of my own projects. I learned an incredible amount on The Iron Giant, and I want to explore some of these new ideas.

Animation Artist magazine is very grateful for the time Scott Johnston took to
share his excellent insight  with Animation Artist readers


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