Motion Capture Animation

Using Performance Capture or Motion Capture Technology to Enable Lifelike 3D Animation – Is it Acting or Animation?

With movies like James Cameron's Avatar pushing new boundaries of 3D animation, the concept of "performance capture" has come to the fore, addressing perhaps for the first time the issue of how to truly merge acting with animation. Unlike previous movies using motion capture technology, where facial movements still needed to be added in post-production by animators, performance capture allows every facial movement and nuance expressed by the actors to be conveyed by their virtual 3D selves.

Nothing is added in terms of facial movements in post-production, so actors are expected to emote fully on camera before the data is exported to their digital selves. The only additional animated movement required is for body parts that may not exist in reality, like tails on the Na'vi. And of course the animation of all the other fantasy creatures, worlds, textures, clothing and 'make-up' required by the story.

Actors themselves have struggled to some extent as to whether these fully or partially animated movies are really "acting" but there is no doubt in the minds of director Cameron and his cast that their acting skills are truly represented on the big screen in the form of the ten foot tall blue Na'vi.

With this level of innovation, the boundaries have been forever blurred between traditional animation, computerized 3D animation, high level special effects makeup and traditional movie making. For the actors, being able to replace hours in the make-up room having detailed makeup and expensive prosthetics applied on a daily basis, with live action footage in simulated green screen environments has got to be a huge step forward. And with the proliferation of screen actors taking key voice roles in animated movies in recent years, most acknowledge that 21st movie making is no longer all about the pretty face or perfect body.

James Cameron has been quoted as saying "I do think that there is an issue here where the acting community needs to be educated about what performance-capture really is, especially the way we did it on 'Avatar,' where we preserved every nuance of the performance."

Cameron has been working on the 'Battle Angel' project to make a live-action adaptation of the first three volumes of the manga series. Like Avatar, the movie will be a combination of live action and CG, with a female actor playing the lead character Alita and using the same performance capture technologies.

Director Robert Zemeckis also used performance capture for his movie Beowulf, starting Ray Winstone. Winstone makes the point perfectly that this technology is really just a post production version of hair and make-up. "What Ray Winstone said is the difference between this and live action is that in live action, you go into hair and makeup, you go into wardrobe, and then you act," says Beowulf producer Steve Starkey. "In this, you act, and then they put on your hair and makeup. There is no difference. You're acting in both, and I say it should be considered as a real performance."

Giant Studios

The creators of the proprietary performance capture technology used by Cameron for Avatar are LA based Giant Studios. Giant's proprietary technology is based upon advanced tracking and analysis algorithms, with a sophisticated suite of software tools that enable 3D animators to create high quality character animation faster and more easily than ever before. Giant's technology consists of hundreds of thousands of lines of code that define the human skeleton with scientifically accurate detail: bone length, density, connectivity, and rotation properties. All of which can be modified to mirror the appropriate skeletal set-up for any mechanism that needs to be animated.

With Giant Studios' technology, the result is organic, accurate animation of each character on screen. Due to the scientific accurate detail within the software, Giant defines specific bone lengths and motion parameters of each character skeleton being captured.

Because the software is robust enough to enable capture and processing of the motion data of multiple characters in one simultaneous process, the director can see in real time the live performance of the animated character, in a digital version of the set, with interactive camera and lighting controls. The director and producer walk away from the capture session knowing that they have the performances and the shots they need, avoiding expensive reshoots.

Motion tracking or motion capture started as a photogrammetric analysis tool in biomechanics research in the 1970s and 1980s, and expanded into education, training, sports and recently computer animation for television, cinema, and video games as the technology matured.

For anyone seeking a career in movie animation, becoming familiar with this rapidly evolving technology and understanding what part it has to play in moviemaking going forward, will be critical to your success.

Article written by Natcoll Design Technology,

Acting and Animation

"An animator is an actor with a pencil", goes the oldest and truest animation cliché. Not "a draftsman that acts", but first and foremost - an actor. If you're trying to tell a story through a character, inevitably you're an actor. The only question is whether you are a good actor or a bad one.

My feeling is that in the past few years, while there's been great progress technology-wise, the art of acting in animation has been abandoned. Compared with the acting quality of characters such as Shere-Khan (The Jungle Book), Captain Hook (Peter Pan) and others, today's characters are pale, dull, and lack personality. In better cases, an exceptionally interesting voice-talent saves the day (Robin Williams as the genie in Aladdin); but usually the script alone is responsible for providing the characters with some sort of personality.

In the various internet forums one can find threads concerning software, design, textures - some even talk about movement - but it's rare to read something about acting. I haven't yet seen a comment saying something like "the animation is good, but the character has no personality". It seems that the level of expectations is so low, that it's enough for an animator not to make technical errors. Would you consider praising a writer simply because he made no spelling mistakes?

In the following article I have put on paper my thoughts considering acting in animation, which apply to any form of character animation - including 3D. The article is not meant to provide a "good acting in animation" formula - simply because such a formula does not exist. Every animator has his personal attitude, every film has needs of its own, and undoubtedly there are other ways of getting good acting. The goal is to propose a "toolbox" for the actor/animator, and maybe raise - even a little - the animators' awareness of acting in animation.

What is good acting?
When I ask my students what they think good acting is, the first answer is usually "believable acting". But credibility is only one side of the story. Good acting is believable and interesting. In my opinion, these two attributes wholly define good acting. With this idea as an axiom, we will try to separately analyze what makes acting believable, and what makes it interesting.

I. Believable acting
In the life of an animator there are short and rare moments of true magic. Those moments are the reason I became an animator, and they are the reason I still am one. I'm talking about a moment in which you look at the animation you've just created, and suddenly you believe your own character. Suddenly it's alive, it's there in its own right. Those are the moments of believable acting.

Believable acting holds a great power over the viewers, because the character they're watching gets a sort of meaning. Every man has meaning to us - even if we don't always think about it: If a total stranger sitting next to you on the bus suddenly collapses, you will not be indifferent - because the very fact that he is a flash and blood human earns him that meaning. This is why we feel sorry when Bambi's mother dies: we believe her and we believe Bambi, and both of them mean something to us. On the other hand, the characters in South Park are anything but believable, which is why there's no problem killing Kenny in each chapter.

(This might be the right place to reemphasize that the animator is of course not solely responsible for contributing meaning to the characters - script has an important part in it too. This article, however, is dealing with animation).

Believable acting means that the audience feels that the character's actions are the result of its own inner motives, and not the animator's inner motives; that the character feels, thinks and reacts consistently according to its personality and mood. I emphasized the last sentence since it encapsulates many of the ingredients of convincing acting:

Feel.
The aim here is not just to portray clear and defined feelings (happy, sad, etc.) but to look for a kind of inner feeling that we have in us all the time - maybe it can be called "consciousness". Try to "feel" your character when you create animation, not just move it around according to the principles of animation.

Think.
Your character shouldn't always act on immediate instincts. Look for opportunities to show thinking process, which leads to decision and action. It will enrich your animation with depth, complexity and believability.

React.
Acting is actually more or less a series of reactions - the character reacts to its environment, to other characters, to stimulus. Every action must have a reason. Make sure you know what your character is reacting to, and that the reaction is reasonable (in other words: it's reasonable that this particular character will react in this particular way).

Consistency.
Retain a consistent attitude to your character's reactions. A shy character (small, timid movements) that unexpectedly acts in an extroverted way with no clear reason, will suffer great damage to its credibility.

Personality.
The character's personality dictates its reactions - i.e., its acting. Again, we are not necessarily talking about a definite personality such as "arrogant", "grumpy", etc. Try to get to know your character the way you know a family member or someone you work with. What makes him tick? What is he afraid of? What are his problems?

Mood.
Mood resembles personality - it, too, dictates the character's reactions - but unlike personality, its effect is temporary. For example: a guy who's hurrying to work acts and reacts in a very different way than the very same guy as he calmly walks his dog in the evening.

* * *

Reading the above notions, one might think - "hey, all those things belong to the script and storyboard! Reactions, personality, mood - I can't control that! I'm just the animator here, my job is merely to move the character around and make sure there's a lot of anticipation!". My answer is in the following example:

The storyboard shows a character entering the frame, and looking angrily at another character. You're assigned to the scene, and the questions that should arise are: does the character enter slowly? Quickly? Determinedly? Hesitantly? Does he stop suddenly or gradually? Did he know the other character would be there, or does he spot it in the scene? Is he furious, or merely dissatisfied? What sort of anger is it - helpless (like a child's anger towards his parents), or superior (like a parent's towards his child)? And so on and so forth.

The actor/animator's task is to carefully read the script, study the storyboard, and try to "get into" the character. In other words: to find the character's inner feeling and to "wear" it for a while as if it was his own - so that he can get to know and understand the character. A good actor doesn't invent his acting - he discovers it. And still the animator faces the tough challenge of putting the experience into his animation, keeping the principles of motion. It isn't easy, but the reward - that magical moment of believable animation - is worth the effort.


By Doron A. Meir