THE PRINCIPLES OF ANIMATION, identified and perfected by the original Disney animators, guide us when we make technique and performance choices in our work. They are not rules, but rather guidelines for creating appealing animation that is engaging and fun to watch.
These seemingly simple concepts combine to inform the most complex animation and performances on screen. Though some translation of these principles must occur for animators to utilize these concepts in Maya, this chapter offers a clear explanation of them and shows you how you can begin applying them in your own work.
LAUDED AS THE MOST IMPORTANT PRINCIPLE, squash and stretch gives characters and objects a sense of flexibility and life. Also, this principle dictates that as characters and objects move and deform, their volume generally stays the same. Some of squash and stretch can be dictated by the object actually smooshing into something, such as a ball bouncing on the ground. With characters, squash and stretch can mean many different things. It can be combined with anticipation to make a character “wind up” for an action in a visually interesting way. One example would be as a character prepares to move, he may squash his spine, making his figure bulge out. Then as he springs into motion, his form elongates and stretches thin to retain the same volume. Whenever possible, use squash and stretch on your characters to give a sense of strain (a character reaching for something high overhead), or to give a sense of fear (a character squashes into a little ball in a corner to avoid being seen by a predator). Start looking for squash and stretch in professional animation and in life, and you'll see quickly how much this simple principle adds to the illusion of life we give objects and characters.
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Squash and stretch isn't only about physically squashing and stretching in a cartoony manner. Also think about squash and stretch in the broader sense of being the contrast between compressed/contained and outstretched/extended.
ANTICIPATION IS THE PRACTICE of moving a character in a certain way to prepare the character and the audience for the action. Most often, anticipation means moving the character a small amount in the opposite direction of the main action. Since a lot of animation is very physical, many times anticipation is a necessary part of getting the correct physical performance out of the character. For instance, a character jumping must bend his knees first. A pitcher must bring his arm back before he throws the ball. This natural motion that occurs in everyday life is what makes anticipation as an animation principle so effective. We are very accustomed as humans to tracking fast-moving objects by taking a cue from its anticipation, and then looking ahead of the object in the opposite direction. So as animators we must take advantage of this hard-wired trait of humans and use it to our advantage. We can make it so that the audience is always looking at the part of the screen that we want them to, by activating the visual cue of anticipation.
Anticipation also serves a purpose in fine tuning your performance choices. Disney animator and animation legend Eric Goldberg is known for relating anticipation directly with thought itself. This makes perfect sense; if we see a character really “wind up” for an action, it is clear to us that the character has planned the action well in advance, and is thinking about how to move. On the other hand, if a character moves instantaneously and without warning the motion comes across as unplanned. Think of the difference between the apparent thought process of Popeye swinging his arm back to punch an unsuspecting Brutus, and Brutus's head when the fist hits him on the back of the head. Popeye was planning to wallop the big bully, but Brutus was not thinking at all of the fist about to hit him! So as you are working, pay close attention to how much anticipation you are using in your animation. It may just mean the difference between a thinking, planning, and intelligent character, and a character simply reacting to the world around him.
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Play your animation at speed! We know that timing is vitally important in animation. You get so much more information playing your animation at speed than you do if you just scroll through the timeline.
STAGING IS A FUNDAMENTAL that encompasses a mass of artistic sensibilities. Staging involves framing the camera in a way to best capture the action. It involves making sure your animation has been planned to best communicate the motion, the character arc, the story. Simply put, staging is how you create the scene.
Ideally staging starts with your planning phase. Thumbnailing your poses is the best way to make strong pose choices at the start of a shot. If you are not a strong drawer, then perhaps you rely more on photo or video references to give you cues to begin your work. At this very early phase, staging means you are thinking about how your posing and the layout of the scene are going to clearly show the motion.
As you begin your scene, staging becomes more complex. How are you going to maintain the high level of communication throughout the life of the shot? Will you be able to hit all of the poses that you'd like, or are the poses going to have to be changed to work when the character is in motion? Staging means that you are thinking about the entire action at this point. Adjusting the camera, making tweaks to the layout, and finding just the right balance in the composition all improve your staging of the scene. When you are finished blocking, generally the major staging decisions have been made. This does not mean that staging is over!
As you finish the animation, there are still staging considerations you must be aware of. Where is the audience's eye going to be looking at every moment of the shot? If you've animated the scene correctly, you have a very good idea of what the audience should be paying attention to at every second. As your shot is finished and moves through the rest of the pipeline, other decisions that hone in the audience's focus are going to come into play: lighting, effects, and editing.
As animators, our staging choices have far-reaching impact on the success of a shot in communicating an idea. We'll practice these staging concepts by repositioning a bouncing ball animation, the camera, and some lights to find the greatest impact.
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It's easy to forget that staging is more than just the camera angle. If you're working on a production, you may not have any control over the camera angle chosen for a shot. If this is the case, you must design your staging within the camera you've been given. This might entail “cheating” poses so they look their best in a particular camera.
If you select a spotlight, and then go to the Panels menu in any panel and choose Look Through Selected, it will create a temporary camera view that matches the view as seen from that spotlight. Many Maya users find using Maya's in-panel camera moving tools to position lights is a fast and easy way to stage the scene. Maya even gives you an in-panel preview of the light's cone angle!
THIS FUNDAMENTAL DESCRIBES the two basic approaches to block in a piece of animation. “Straight ahead” means that an animator creates the base animation by posing the animation in a frame, then moving forward one or more frames and posing again. This approach is akin to stop-motion animation, in which you have to pose every one or two frames because the camera needs to capture that frame on film before moving forward. “Pose to pose” means that you create the key poses, and then essentially time the rest of the animation by inserting blank or “hold-poses” in between your key poses. This is akin to a non-linear approach in which you can test different timings of a shot by simply sliding poses around on the time slider. Both approaches have their advantages and disadvantages.
Straight ahead animating should be used when the action is very mechanical or physical. This is because the ability to perceive the motion as you frame through the animation in slow motion is far greater than trying to imagine what pose the highly mechanical or physical movement is going to hit. Let's take an overlapping antenna, for instance. With this kind of highly physical action it would be impossible to imagine where the antenna is going to be without framing through the animation and adjusting the pose as you go. This is what we'll do to practice this concept.
Pose-to-pose animating should be used for creating character performances. Unlike highly physical actions, the key poses a character hits are going to tell the story. So in order to be sure that you arrive at these golden moments, you should pose them out and retime them as necessary to make the motion work. We bias our work in performance animation to feature the pose because, without a strong sense of the character's body language, the emotional story gets lost. We're going to create a pose and retime it using Maya's Dope Sheet.
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As we demonstrated in this example, straight ahead usually works best when there is a frame of reference to judge the movement by. In this case, we knew what the antenna should do because of where the ball was. Don't confuse animating straight ahead with animating blindly. That rarely turns out well, even for experienced animators. Always have a good plan for what you are going to animate beforehand!
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You can get a nice settle in a pose by selecting all of your controls, then middle-mouse dragging and copying a pose from a few frames before your last key pose to a frame 6 to 8 frames later. This method needs adjustment to make it look perfect, but gives you a very quick and easy settle to start working from.
OVERLAP AND FOLLOW-THROUGH are the two most intuitive fundamentals in animation. Both basically deal with the principle that it takes energy to move objects and also to slow them down. “Overlap” is what we call it when an object “lags” behind the main action. “Follow-through” is what we call it when an action overshoots or goes past the end pose.
Overlap instills a fluidity in character animation. When added to your character's gestures, overlap makes the animation feel like the character has a natural limber quality. When a character swings his arm, the bending of the wrist has a nice organic quality. Natural rise and fall in the spine in a walk cycle makes it feel calm, while an extreme amount of overlap in the spine in a walk can make the character look depressed and sad. In this way we can see overlap has a very major impact on the performance of a character.
With follow-through, the main thing you can show is a sense of weight with your character. The heavier the weight, the more energy it will take to stop the character. Use follow-through to emphasize this.
We've already had some practice with overlap in the last section, but let's get some more practice with a simple animation of Goon landing from a jump.
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Simply offsetting the curves is a common trick, but it will rarely get you finished overlap and follow-through. You will almost always need to diligently polish the curves to get “final worthy” results!
SLOW IN AND SLOW OUT, also called ease in and ease out, refer to the spacing of the keys when an action comes to a stop or changes direction, or a character transitions from pose to pose. This principle means to animators that we typically decelerate objects as they come to a stop rather than have them come to a dead halt instantly (“slowing in” to the pose). It also means we should gradually accelerate objects as they begin to move and not have them instantly be at full speed (“slowing out” of a pose). In the Graph Editor of Maya, this principle is simply illustrated by flat tangents. It is easy to see how an object slows in to a change of direction in the Graph Editor when we look at the curves of a bouncing ball. As the ball arrives at the top of its arc, and also the flat tangent of the Y curve, it decelerates evenly before changing direction and accelerating again.
This is not a blanket rule, however! Not every action should slow in and slow out! In the bouncing ball animation, when the ball hits the ground there will be no slow in or slow out. Instead, we animate those tangents with a very sharp direction change as a result of the ball hitting the solid ground and having to change direction instantly. Consider also an animation of a character running. The feet are going to be really pounding the ground, meaning the legs are still going to be accelerating as the foot hits the ground. “Flatting” all of your tangents in the Graph Editor is a common mistake, as is having flat tangents be your default tangent type. True understanding of slow in and slow out means understanding which situations should have nice eased poses, and which ones should have stark direction changes. We are going to take advantage of Maya 2013's new editable motion trails to practice when to use slow in and slow out. Also check out the Splines (Chapter 2) for more details on slow in and slow out.
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You can view the Tangents, Beads, or the Keyframe itself, one at a time, but never all at once. Maya does this to reduce scene overhead and to keep working with editable motion trails simple and straightforward. If you ever get confused, you can always delete and recreate the editable motion trail from the Outliner – doing so does not delete the animation itself.
EARLY ANIMATORS OBSERVED the interesting fact that most natural actions follow an arced path. They then practiced applying this trait to their animation to create more appealing movement. This came to be known as the principle of “arcs”. To avoid giving mechanical, robotic performances, check your animation constantly by tracking objects on screen and make sure they do not follow linear paths. Remember to check your arcs from all angles first, but finally and most importantly from your camera view; this is the view the audience will see!
Another very common mistake is to only track arcs on major body controls. As animators, we tend to bias our attention to the controls that give us the gross pose of a character: Root, Hand IK, Foot IK, and Head. All too often, beginning animators will then try to track the arcs of their animation, but because of all the attention and time spent using only four or five main controls, will only look to these areas for smoothing. This can lead to a visual discontinuity within the animation of the body. Instead, you have to look at the entire body, and determine the forces in the body. A fantastic resource for learning how to determine the force in a pose is the book Force: Dynamic Life Drawing for Animators, published by Focal Press. Investigate how the entire pose itself has rapidly changing, dynamic shapes, all of which need to move naturally and on arcs.
For our purposes, we are going to adjust the arcs on a full- body turn animation. Our character is looking towards screen left, when he suddenly turns and looks towards screen right. There is no breakdown key in the middle of the turn, meaning there is only a very drab, linear interpolation happening between the left and right poses. To fix this, we are going to add a breakdown and improve the arcs of the turn.
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If you want to be able to edit the arcs of your arms in panel, try re-animating this shot with IK arms enabled, and by adding an Editable Motion Trail to the controllers after blocking the animation. The visual feedback of motion trails has always been very useful, but now we can use them to actually improve the animation, all in camera!
THIS PRINCIPLE REALLY GIVES a scene some deep subtext. Secondary action is any action that is not the primary action in a scene. A character sharpening a pencil as he complains to his boss would be secondary action; the primary action has to do with the poses and body language involved in speaking to the boss. A character running his hand through his hair as he turns away from the mirror, giving himself a wink, would be good secondary. The main action in this example is the turn, but the hand through the hair adds a nice level of meaning to the whole scene.
The wonderful thing about secondary action is that there really is no amount that is too much. Especially with humans: we're constantly multitasking, constantly occupying ourselves with more than one thing at a time. The animation can, of course, become too busy. The fact is there is a balance, but for the most part your scenes can always use an extra level of animation and therefore subtext.
The way master animators truly utilize secondary action is by “coloring” the action to suit the subtext of a scene. This means changing the secondary action in pose, timing, spacing, etc. to distinguish it from a normal, “vanilla” performance of the same action. Let's look at an example. Let's imagine a scene where a mother is ironing clothes while looking out a window. Her husband walks into the room and tells her that their son has been killed in war. She is facing away from him, and still continues to iron. But her body language changes. Her hands start shaking. She looks like she's about to faint as her eyes well up with tears. The adjustments to the action of ironing clothes (the secondary action in this scene) is what we call coloring the action. Now imagine the same set up, with the wife looking out the window and the husband entering the room. This time, he enters and simply asks her how her day was, but this time, she found out that morning that she is pregnant. She answers him “Fine,” and smiles. How would you “color” the secondary action in this scene? When she hears the husband enter the room, would she excitedly speed up her action? Maybe she got some baby clothes out of a box and that's why she's ironing. She'd then pause and look at the clothes as she describes her day to her husband. Suddenly, through secondary action, animators have access to an enormous amount of subtlety in a scene. I like to call secondary action the “window to subtext”.
We are going to do a simple trick with Animation Layers to practice using secondary action to show subtlety in a scene. In our scene, Goon is sitting at the library, tapping his finger, very bored. Then someone he really likes walks by, and his eyes follow them. By animating the weight of the animation layer with the finger on it, we are going to “color” that action; basically, he forgets to tap his finger while he is captivated by this person walking by. Secondary action can be so subtle, that sometimes just STOPPING a secondary action is enough to completely color it!
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Check out Chapter 12 for an in-depth look at Animation Layers and how to use them.
If you are unsure about a secondary action, sometimes it can be better to key the main action on the master animation layer, and only when it is looking solid, key the secondary action on a new Anim layer. You can always turn off the layer if the secondary doesn't work out, without fear of destroying your main action.
TIMING IS LESS A FUNDAMENTAL than it is the very foundation of the art of animation. Animation is, of course, just a series of still images that flash by fast enough to create the illusion of motion. Our task is to use timing not just to accurately portray motion in realistic scenes, but to use timing as a method to convey meaning in a scene.
In character animation the main goal is to get your audience to empathize with a character. As they succeed, the audience celebrates; when they fail, the audience feels their loss. As animators we can get so caught up in the physics and mechanics of the motions that we create that sometimes we forget the timing of a scene can be improved to tell a deeper story. The pauses in between actions can have more powerful messages than the actions themselves.
In the last section, we adjusted the secondary action of the character to show that he is so captivated in that moment that his hand just naturally stops moving. It has a subtle but powerful effect on the performance of the character. Although a full animation curriculum on timing is outside the purview of this book, we can definitely experiment with this scene to give ourselves some insight into the powerful effect subtle timing changes can have on a performance. We'll use the keyframe editing tools in the timeline and Graph Editor to make these adjustments.
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Novice animators often struggle with the difference between timing and spacing. While they are connected to each other, they're NOT the same. A movement over 10 frames can look completely different depending on how you change the spacing, even though the actual time in which it moves (10 frames) stays consistent.
EXAGGERATION IS ONE OF THE SIMPLEST, yet most misunderstood principles of animation. Why? For decades novice animators have tried to blindly exaggerate their animation to try to recreate the amazing cartoony styles of the animators of yore. However, exaggeration doesn't necessarily mean better animation, or even more cartoony. Exaggeration must be used with a keen eye for the effect you are trying to achieve.
Find the core idea in your scene and figure out the best way to exaggerate the message. If you are animating a character getting pricked on the butt with a pin, then you are going to exaggerate the timing and spacing of him shooting into the air. If you are animating a character that gets scared by a spider, you might exaggerate the squash and stretch in his body by having his legs run away from his torso, stretching out his spine! In both of these cases we choose the main idea and exaggerate only where we need to in order to strengthen the message. Both scenes would look way over-complicated if we had exaggerated the posing, timing, spacing, composition, weight, anticipation, etc.
Your animation scenes in Maya should be as lean as possible. To illustrate how easy it can be to exaggerate a fundamental, we're going to take a finished walk cycle and adjust the overlap in the spine using the Graph Editor. Your workflow must create animation that has minimal keys, therefore making it easy to change the animation later on. For our purposes, the overlap in the spine on a walk cycle is a great fundamental to experiment with, because it has such a large impact on the performance.
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To make reselecting the same channels easier, select a channel (Rotate X for example) and in the Graph Editor go to the menu and click Show > Show Selected Type(s). You'll see that only the selected channel now shows on the left side of the Graph Editor for all selected objects. This is a good cheat to use when adjusting a single fundamental like we did on the spine. Restore the other channels by clicking Show > Show All. The Graph Editor is covered in depth in Chapter 3.
AT FIRST GLANCE, “solid drawing” has little to do with CG animation in Maya. What does drawing have to do with animating on the computer? On the contrary, this is an extremely important fundamental to remember when creating animation on the computer. Why? As CG animators, it is very easy to relax our artistic sensibilities and let Maya do all of the work. However, the moment you forget the art of pose, perspective, form, volume, and force, you will quickly see your animation dissolve into unappealing mush. Solid drawing is a fundamental that persists from the hand-drawn days of cel animation. What it basically imparts is a dedication to the figure-drawing principles that the master animators all adhered to. When you started your drawing, you always had to begin with the same basic construction of the character: simple shapes combined with clean, meaningful lines, taking into consideration the line of action, the force of the pose, and the weight of the character. Perhaps most of all, perspective and a sense of the character's volume had to be extremely consistent. In other words, all 24 drawings per second of animation had to look like the same character.
In CG, we have a lot of help from Maya to achieve solid drawing, but we should pay close attention to make sure we aren't being lazy. Since we are working with 3D models, for the most part Maya takes care of staying “on model.” Even so, you have to be careful not to pose your character in such a way that the body or face is distorted so much that it doesn't look like the same character. Most of the time this happens when an animator hasn't thoroughly tested the rig, and is using controls to create movement that were not intended for that purpose. In CG we can indeed go off-model, and it is your job to avoid this.
We are going to fix a piece of animation that has some very bad counter-animated controls, and is also experiencing some skin-weight issues. Speaking strictly as an animator, you don't have to be as concerned with technical issues, but remember that CG animation is often a team effort, and solid drawing is the result of everyone working together.
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Instead of deleting the curves themselves in the Graph Editor, we can delete animation from a channel by right clicking on that channel in the Channel Box, and clicking Delete Selected. This will delete the animation on the channel, not the channel or the attribute itself. Remember, the channel's value will remain at the current frame value whenever you delete all animation.
IT COULD BE SAID that all of the fundamentals combine to make “appeal.” Beautiful, organic timing is appealing to the eye. Interesting, dynamic posing is also appealing. Character designs, contrasting shapes and rhythm, are all fine tuned, worked, and re-worked to get the most appeal. Does appeal mean “good”? Not at all: the evil villains in our most beloved animations all have appeal. From their striking silhouettes to vibrant colors, even the bad guys must be appealing. Appeal is the pinnacle of our task as animators, it is the goal. Above all else we should strive to always put images in front of our audiences that are worthy of their time.
Let's focus on posing for our discussion of appeal. As animators our work takes place far after the characters have been designed, modeled, textured, and rigged. But even with appealing characters, bad posing can ruin the entire show. For instance, an arm pointed directly at camera loses all of its good posing from foreshortening; the animation must work well with the chosen composition. Take the camera into consideration and be sure that your staging is well thought out. The silhouette of your pose should be strong, without limbs lost within the silhouette of the body. And “maxed-out” or hyperextended arms and legs never look very good.
Twinning is another major issue in posing. In nature, nothing is ever perfectly symmetrical. Without being careful to avoid twinning, it sneaks its way into our animation. It saves time, for instance, to set channels on both sides of a character at the same time. If this is a cheat you use, then you must remember to go back through the scene and un-twin your poses. Arms, legs, hands, even facial poses can fall victim to twinning.
We must be mindful of the appeal of our animation by constantly critiquing our work and showing it to others.
To practice, we are going to take a single pose and make some adjustments to increase the appeal.
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Always keep an eye on the renderCam. As animators we want our animation to work in 3D as much as possible, but when it comes down to it, the animation needs to look good through the main camera first and foremost. Working with the renderCam open somewhere is good workflow practice.
IT WAS YEARS into my teaching career, with hundreds of classes and thousands of hours of animation critiques under my belt, before a student suddenly asked me, “You keep on saying the word ‘workflow’, but what does it mean?” I was stunned, because after all of my harping on the subject, it never occurred to me that the very concept of “workflow” itself might be unclear to beginner animators.
Simply put, a workflow is the step-by-step process you employ to create a shot from start to finish. It adapts to the project, it grows and changes slowly over time, but on a shot-to-shot basis your workflow always stays the same.
This may sound like a no-brainer, but the reality is most new animators pay little to no attention to the actual process as they learn. Instead, they animate ”by the seat of their pants,” and look at the unpredictable results on screen for indications of improvement. Let's take a related example in another area of art to illustrate this point.
Back in school, I had a figure-painting teacher who was very strict. His name was Yu Ji. In his class, students were subjected to a constant barrage of commands regarding how and when to do each step of a painting. First, you wipe the canvas with some highly thinned burnt umber or raw umber paint until the entire canvas is a nice, fleshy brown. Then do a quick sketch in pencil to define the form. Immediately go over that with a thin brush with umber paint, completely filling in all of the shadow areas. THEN, and ONLY THEN, do you start mixing paint to try to match the colors you see. And even when it came to finally painting with color, Yu Ji sounded like a broken record as he walked through the class to correct the color choices of his students. “Is the color warmer or cooler than the color next to it?” “Is it lighter or darker?” “What is the color tendency?” (Within warm colors, was it more red, or yellow, for example.) These same three questions were repeated at least a hundred times over the course of a three-hour class.
It would be years before I realized that what Yu Ji was doing was teaching us good workflow, above all else. Everything we were forced to do helped us avoid the major struggles that befall young painters. Most importantly, these were tried-and-true methods that produced better results. For instance, making the entire canvas brown made it so that we did not mix our colors too light just because they were competing with a blinding white canvas. Filling in shadow areas early on and foregoing minor details made the students focus on the large shapes in the form. Finally, his three questions made it so that we were mixing our colors based on the color relationships that we saw, barring preconceived notions from influencing our color choices. When I think back on it now, I cherish the amazing workflow that Yu Ji gifted his class, and I feel bad for thinking he was so strict!
Back to animation.
In animation, students typically start with a workflow that roughly resembles the order in which they learned the fundamentals. Pose the character with some rough timing and spacing, add some squash and stretch here, some anticipation and follow-through there. This is a messy way to work, and until you learn how to really let the fundamentals work in concert, your animation will lack the fluidity and beauty that the legends are capable of. There are just as many pitfalls awaiting novice animators as figure painters. In Yu Ji's class, we were forced to make our canvas brown so as not to wrongly exaggerate the colors; perhaps the first step in your workflow should be to not thumbnail some REALLY pushed poses and try to hit them with the model. You would be doing this because you know that as you move forward with the shot and get into polish, many of the pose choices will become watered down to accommodate timing, spacing, and compositional constraints. Yu Ji made us fill in all of the shadow areas with brown before adding any details. Sounds a bit like getting body movement looking really good before adding facial animation, doesn't it? And finally, those three questions we asked ourselves reminded us to constantly critique our choices within the painting, and with the live model. Before you move into your polishing phase, it would be a good idea to establish a workflow step in which you look at the animation one more time and ask yourself some questions. “Are my poses as dynamic as I originally planned?” “Is there still contrast in the animation in pose, timing, and composition?” “Does this resemble the reference and observation I've gathered?”
Your questions might be different, but the main point, both in figure painting and animation workflow, is that you do it every time. Instead of leaping at a shot with no plan in mind, just begin at step 1 of your workflow. Stop animating feverishly for huge lengths of time only to step back and realize the shot has not progressed at all.
If at any time in the middle of animating a shot you catch yourself asking the question “OK, now what's my next step?” you know you've crossed into the world of workflow. Welcome! You are on your way to becoming a great animator.