Friday Flashback #393

Of Mice and Models

By Karen Moltenbrey

A series of UK television commercials for Aero candy stars some extremely talented digital mice who sing, dance, and even hula-hoop. Despite their efforts, the mice fail to impress chocolate buyers and scurry away dejected. The ad campaign began with a 30-second commercial featuring one hula-hooping mouse, who is joined in a second spot by dozens of others, including one that sings Chinese opera and performs an elaborate, oriental-style dance. The most recent spot, which is expected to air soon, contains a group of mice performing a complicated Irish step dance.

Creating these gifted photorealistic creatures and giving them naturalistic move ments required a similar amount of talent and ingenuity on the part of the modelers and animators at digital effects house Glassworks and animation production company Passion Pictures, both located in London. According to Alastair Hearsum, head of 3D at Glassworks, the computer-generated mouse in the film Stuart Little set a high standard against which the audience would judge the Glass works character. For its Aero mouse, though, Glassworks chose a different tack by dispensing with the character’s clothes and opting for a more realistic approach compared to the stylized Stuart in terms of appearance and movement.

“The challenge was to create a mouse that the audience believed was real,” says Hearsum. “It had to move like an actual mouse, and have realistic proportions and features.”

The 3D animations of the mice were inspired by 2D pencil drawings from Passion’s visual effects director Chris Knott and animation directors Tim Watts and Alyson Hamilton, who had collected various mouse images before making character drawings. The duo worked closely with Hearsum to produce the convincing personalities of the mice. Glassworks then constructed the mice models, added realistic fur, and animated them to move under Passion’s guidance and direction within a live-action environment.

“There are no complicated rigging setups, layered expressions, or complex shaders with the exception of the fur,” notes Hearsum. “But that’s not to say that the project wasn’t challenging. One of the more difficult aspects was getting the mice to look sweet and move in simplistic yet charming ways.” This was accomplished, in part, by using a fairly blank facial expression for all the creatures, so they wouldn’t look anthropomorphic, despite their humanlike actions.
Digital effects house Glassworks and animation production company Passion Pictures teamed up to create a series of television commercials for Aero candy in the UK that feature dozens of realistic mice performing some amazing but unrealistic stunts.
Mouse Modeling
Whether a scene has one mouse or a hundred, each character originated from the same model, which Hearsum built with separate NURBS patches using Soft image|3D running on an SGI Octane system. He then constructed a complex skeletal structure for the model, whereby the skeletal parts that were controlled by inverse kinematics (IK), such as the arms and legs, would be limited to two connecting joints. With this structure, the shoulders were not part of the arms, but linked to them as parents rather than children in the chain. That setup, combined with the vector constraints, gave the group total control over the movement of the arm and shoulder, for example, and eliminated rotational or other range-of-motion issues that can occur when multiple joints are interconnected within the bone structure.

To achieve the intricate and realistic foot animation in some of the scenes, Hearsum set up the root of the foot’s bone structure at the bottom of the foot rather than at the ankle. This made it easier to keep the ball of the foot stationary when the animators stood the mouse on its tiptoes. Specifically, the foot’s main bone structure contained one joint with the root positioned near the toes, and the effector (the endpoint in the chain that poses the rest of the chain) positioned at the heel and ankle areas. The leg effectors, meanwhile, were constrained to the effector of the foot joint, and the middle three toe bones were constrained to the root of the main foot bone. “Therefore, when the mouse stood up on its toes and its foot was bent, the toes remained flat to the ground,” explains Hearsum.

Each mouse was constructed with (left to right) NURBS patches, a skeletal structure, a combining of the two, FurShader texturing, then various levels of shading and texturing. The finished mouse as it appears in a commercial is shown below (bottom image).

For skinning the model, the artist used Softimage’s binding box feature, which automatically includes or excludes the points associated with a particular joint that falls within the box. “They are a pain to set up, but by using them, I was able to reskin the mouse in a matter of a few minutes,” says Hearsum. “Early in the process, the mouse was in a constant state of flux, especially the facial region. Using the binding boxes enabled me to quickly and easily accommodate changes from the client.”

Fur Real

The modeling efforts only scratched the surface when it came to achieving a photorealistic appearance for the mice. The key element was the hair, created in Glassworks’ FurShader, a combination Softimage|3D plug-in/Mental Ray shader that has been in de velopment at the studio for the past three years. It was first employed for models of spiders appearing in TV commercials for other brands. The software provided wireframe control hairs, and by directly manipulating the control hairs through their individual IK, the group was able to style the fur to create a different look for each mouse appearing in the series.

“For instance, FurShader enabled us to give the opera-singing mouse a more feminine demeanor by making its coat fluffier,” says Hearsum.

During the rendering process, FurShader fills in the gaps between the control hairs with a specified number of hairs. On average, each mouse had roughly 500,000 hairs. The software also controls the tip and root color, and thickness of individual strands, enabling the artists to create a unique appearance for many of the characters. “Its own antialiasing eliminates any ‘buzzing’ problems that can result when you have a lot of fine detail in a frame, which can interfere with the scan lines of the TV,” says Hearsum. Furthermore, each hair is fully raytraced and integrated into the scene during rendering rather than postproduction. As a result, the hairs cast and reflect shadows. “It truly made a difference in the realism of each shot,” he adds.

For the original commercial, the artists created a single mouse using Softimage and Glassworks’ own FurShader software. The numerous mice appearing in the subsequent spots were all generated from the original model, but given slightly different feature

As a final touch, Hearsum used a great deal of motion blurring. This helped to seamlessly integrate the models into their respective live-action scenes, which was done using Discreet’s inferno. “The mice are moving quickly in the commercials, and we used motion blur so they wouldn’t look computer-generated next to the live actors and scenery,” he explains.

It’s a Wrap

Even with the mouse “cloning” process, it took Hearsum’s team several weeks to generate the numerous characters and their complex movements for the subsequent commercials. “There was more work in the first scene of the second commercial-which had five mice-than in the entire first commercial, which had just one mouse in each scene,” says Hearsum.

Although arduous, bringing the CG mice to realistic virtual life was rewarding for those at Glassworks and Passion Pictures. In fact, the studios won accolades from industry peers for their work on the initial project, receiving two British Television Advertising Awards for Best Animation and Best Computer Animation.

Karen Moltenbrey is a senior associate editor for Computer Graphics World.

Friday Flashback #389

Blue Line Guy



1smIn a recent spot for AT&T, ad agency Wunderman and New York’s Quiet Man emphatically proved they know when and how to draw the line. “Blue Line Guy” is a 60-second animated spot designed to promote AT&T Worldnet Service Plus, the telecommunications leader’s all-in-one internet package that encourages all you prospective users of the service to draw from your imaginations about perfect service. By way of example, the spot offers a particularly imaginative character doing just that.

According to spot director David Shirk (Quiet Man’s head of 3D) and his team, the challenges of “Blue Line Guy” were substantial, and only exacerbated by the project’s very tight six-week deadline. As a result, most of those twenty-one days were eighteen hours long. The results, however, were definitely worth the great effort.

“It’s a good thing that we all love this job, or this project would probably have been impossible,” says Shirk with a chuckle. “The creative team was fantastic to work with. The agency producer, Sue Chiafullo, was impeccably organized and really understood what it takes to do animation. We ended up having a great time, and SOFTIMAGE®|XSI™ was a great help.”

Set against a paper-white background which occasionally and conveniently tears to reveal vital information, “Blue Line Guy” opens with an outstretched outline of a stick man using a deep-blue crayon to draw both himself and his dream internet service. When the voiceover speaks of faster log-ons, the Blue Line Guy transforms into a Zorro-type character, using his blue crayon to slash time off connection speeds. When the topic changes to instant messaging and chat services, the character speaks to his crayon and is joined by another character. Finally, slightly more fleshed-out characters appear on a crayoned computer screen to represent video email.

4smClearly unfinished but completely fluid in his motions, the crayoned character of the Blue Line Guy somehow manages to convey both the creativity of simple hand drawing with the precisely-organized planning of a blueprint. The effect is one of the purely imaginary about to made real, brilliantly exemplifying AT&T’s declared effort to turn the every day into the extraordinary.

“From the beginning, the agency knew what they didn’t want to see in the spot,” says Shirk. “They had a good storyboard, but they told us right away that they did not want the spot to look as if it were traditionally animated. Even though they wanted this character to be drawn with and carry around a blue crayon, they did not want the quirky, hand-drawn quality that the scenario might imply. It was very important to them that the Blue Line Guy look three-dimensional and have the coherence of a genuine character. Our technical director, Bradley Gabe, did a great job with shader development to help us determine how this character might look in 3D space.”Asked to describe some of the project’s bigger challenges, Gabe hesitates for a moment before replying. “Geez, where do I begin?” says Gabe. “Maintaining a level of consistency from frame to frame was one of the biggest challenges. In a texture that is meant to look like a crayon drawing, there are all kinds of problems regarding distortion whenever you’re using 3D. That was kind of tough to figure out, but the Render Tree in SOFTIMAGE|XSI helped me to develop some really great shaders. With some help from SOFTIMAGE|XSI, I was able to come up with a solution that would give us the right look, and still not hit our computers too hard.”

With just six weeks to complete the entire job, the Quiet Man animation team admits to some concerns about creating a believable animated crayon drawing in 3D. “We were quite concerned about how the final animation would look,” admits Michael Wharton, senior animator on the project. “Crayon tends to look very granular, like a bunch of dots really. With only six weeks to produce the entire spot including pre-production and rendering, we had to ensure that our production pipeline was completely established technically. For me, the challenge was animation, animation and re-animation. Following Dave’s lead, we all worked hard to get it right.”

3smPart of “getting it right” required some further yeoman service from technical director Gabe. Working through the many iterations of “Blue Line Guy”, it became increasingly clear that it would require an unusual amount of switching between FK animation, where a character’s limbs travel through space seemingly on their own power, and IK animation, where a character’s limbs are momentarily rooted to a portion of the environment it inhabits. Unlike most commercial animations, FK-IK switching was often required within a single animation.

“What I wanted to do was create a rig that would keep things as simple as possible for controlling this biped character,” Gabe explains. “When we realized that the character would have to do things such as pull a crayon and be pulled around the scene, I knew I would have to create a rig that was slightly more complex. Essentially, it was my job to set up a rig that would allow the character to do perform both FK and IK animations and occasionally switch between the two in the middle of an animation. This character rig really had to do everything.”

2smAs the project progressed and evolved, however, Gabe’s rig had to keep up with the many changes being implemented. It was at that point that SOFTIMAGE|XSI was of particular value, according to Gabe: “SOFTIMAGE|XSI has some fantastic tools for moving animations from one object to another. If you maintain a consistent naming convention that can be recognized across iterations of the character, you can transfer the animations you’ve already done to each new version of your character. We had some things to iron out, of course, but now that we’ve worked through this very challenging project, we’ll be able to use this rig on future projects.”

“The SOFTIMAGE|XSI Animation Mixer was also a big help in facilitating the process of this project,” agrees Shirk. “With all the retroactive changes made to the character’s rigging, we were able to use the Animation Mixer to create animations and easily transfer them to the new characters. We could make all kinds of changes, and it would literally take just a minute or two to get the character up again in its new version. That was awesome, because we never had to be afraid of going back to make changes. It was really, really simple to propagate them back through the chronology of the spot.”

Gabe concurs and continues: “A lot of seemingly impossible things were possible in SOFTIMAGE|XSI,” he says emphatically. “Setting up a lot of different render passes and that kind of thing took a minute instead of the hours it would have taken before. That was fantastic, especially towards the end of the project.”

And, in just sixty seconds, “Blue Line Guy” truly says it all.