Perfect Imperfection

I love animation that shows us something we recognize, and we all recognize imperfection.

I wanted to do a post on how it can be really great to add imperfection to your animation, and in this case specifically how sometimes things like a perfect ease-in or overshoot can add an element of falseness to your work when creating animation in a certain style. I say this because I was watching the shots of a particular animator here at DreamWorks who does a wonderful job of this, and wanted to understand this a little more and include it more frequently in my own work.

When I used to animated in Maya, I was never a curve editor animator. I would just look at everything in the shotCamera, and track arcs in 3D using my motionTrail script. Here at work, the software we have for manipulating curves is so good, I quickly started doing a lot of stuff in the curve editor and making a habit of smoothing stuff out cleanly and watching to make sure that everything was easing in and out nicely.

I really love using the curve editor, and probably wouldn't go back to doing it all in the viewport, but I recently noticed that my movements were becoming too smooth, too calculated and my animation was losing some of that naturalistic punch that I used to see in my older stuff.

I usually go back to live action to figure out how things really move and how it relates to animation, and below I've shared a few videos that show examples of where we may be tempted to oversimplify and oversmooth the movement. In reality there is a lot of "imperfection" that we see in the arcs of movement without really realizing it, but its part of constructing our perception concerning whether or not something is real.



You can see immediately that the arc and the spacing on the foot is not what you might expect if you just started animating this from scratch...

The arc above shows how the curve might turn out based on our assumptions, and what were used to implementing. Its pretty "perfect" and quite different to how the real foot travels through the air. This would probably result in a semi-decent looking animation, but with something looking not quite right or as if not enough detail existed in the movement.

Instead of going nice and smoothly over the top of the arc, the foot drops slightly before it rises up again at the peak. This is the natural arc as the lower leg swings forward.

Theres an interesting section here where the foot slows down before it begins to fall. If you click back on the video, we see this as a slight pause in the leg, and it illustrates thought in the characters mind... a moment of calculation as his brain thinks about the best place to land the foot.

Notice how the foot doesn't fall to the final contact pose with that perfectly accelerating downward motion, its spacing is almost linear after it starts to fall, then suddenly accelerated just before the contact. The foot is not an object freefalling through space - the leg above it can alter and "imperfect" the spacing as it falls.



As the woman gestures, she holds out her hand, and for a part of the gesture she appears to hold it relatively still as she moves it screen right...



When we track this "smooth" part, its clear how irregular the arc is. Despite the fact its not obvious when we watch the video above, its all going on under the hood, and adding to our perceptions of whether or not the character is real.

The movements of the head are a particularly ideal place to use this idea. When we start animating, we quickly learn about what can make head moves appealing - such as dipping the nose on a turn, a slight nod or twist in the opposite direction before a change etc. These are by all means valid, and used wisely can really add to head animation. Take a look at some of these videos below where I tracked the nose to see how the head is moving, and you quickly see how "wobbly" and unsmooth the curves are. I find this stuff really interesting to study.





Here's another curve we might normally be tempted to smooth out - reducing its subtle realism. I love the little bump at the top, and the small "glitch" in the deceleration at the bottom of the curve.





The guy in the blue shirt above shows how erratic the arcs on a head can really be. Whether or not your shot would call for this kind of detail depends on many things, but its just really interesting to me to see how crazy it can get, on a move that isn't really that extreme at all.



Without getting into the subject of overlap and inherited motion, you can see clearly how a more complex action like sitting down and adjusting weight and balance can increase the scale of these direction changes.

Even movements that are supposed to appear smooth and elegant may contain these irregularities, they are just smaller and less noticeable.



The arcs are almost "smooth" but not quite. I might be tempted to round out the tops of the curves and even out the spacing, but these subtle effects can increase the believability.

As far as how to implement these irregularities, it is definitely something I would recommend doing right at the last stages of polish. You can do this by just playing with the curves and adding little bumps and notches, but it can be very hard to get it to look right, and not like you just screwed up smoothing your shot...The reason for calling this post "perfect imperfections" is because nature will always do this exactly right! If your software supports it, I would even recommend doing this on another animation layer, that way its easy to experiment and scale things bigger and smaller without changing your main acting underneath.

Its important to mention that in animation we don't strive for "realism", we strive for communication of the idea. If the idea is ultra realism, then yes we animate as realistically as we can, but normally we are extracting the essence of movement and simplifying it to make the statement clear. So then, are all these imperfections necessary? no, I don't think they are absolutely needed, but they do add a layer of information to the idea you are communicating - audiences all know instinctively that natural motion is varied and irregular, and by including this in your animation you help make your characters appear more lifelike - which may make the audience more likely to believe what they have to say.

Quick Trick: Track Those Arcs

OK, so poses are real important, timing is really important, in fact it seems there are 143,311 things that are really important in animation. One of my favourite out of the huge principle pile however is the concept of arcs. More specifically, I mean that practically all movement on your characters should describe a clean and natural arc through 3D space ( or mostly 2D really - unless like me, you work in games ).

To be honest I`ve known about arcs for a while, but only recently have I started to use them. Oh man how important they are. To discuss WHY they're important aesthetically would take all day, so I`m gonna stick to one aspect of their use for now - and thats mainly just keeping a handle on how smooth and dynamic your actions are.

Using a visual arc tool in Maya can really REALLY help you with your motions... during animation, but also afterwards for finding exactly where all those tiny pops and glitches are. The curve can help you see how smooth and 'organic' your motion is, and the spacing between the objects that represent each frame can visually show your spacing which is super useful.


note: don't confuse this with a "path" animation where an object is constrained to that path. The sphere is animated freely, and the curve updates as changes are made to describe the motion through space.

Some very basic examples of using arcs

• on everything ( arcs don't necessarily have to be smooth curves ! )
  
• on walk cycles - see the path of action on the feet , and the ease-in and outs of the foot plants.
• use a trail on the tip of a character's nose to make sure the head movements are natural and spaced well.
• on a jump - see the gravity through the spacing, and path of action visually with the trail.
• keep track of a complex arm movement, by using a trail on the wrist, and another on the elbow.
  

If you've ever used Maya's motion trail tool before, you probably know its a little suspect. I used 3DStudio Max when I was at Ubisoft, and one thing I did like about the package was it's really fantastic motion trails. So I wrote one for Maya that essentially mimics it exactly - and its also a little more straight forward and visual to use than Maya's own ones.


Trails will update dynamically as you change animation on your object. You can have any number of trails per scene, and even on varying frame ranges of the same object.

You can get it here: cMotionTrail