Do Me A Favor…
Favors, Eases and Other Mysteries of Space
One of the pitfalls of the educational experience for many CG-first animators is that we are, by and large, completely divorced from the traditional roots of animation. Few animators who begin animating first in CG have a firm grasp of the workflows, terminology and principles of animation that have been in existence (and working just fine, thank you) for well on 70+ years now. It’s like we are living and working as citizens in a country where we know little to nothing of the history, language and culture that came before. (kinda like Americans, I guess. But I digress). That ignorance can’t but hurt us in the long run.
One such area of confusion for many CG animators (myself inlcuded for many years) is the concept of spacing and timing. Once you get your head beyond the revolutionary (!?) idea that timing and spacing are not the same thing but are two sides of the same coin, then you are faced with the struggle to understand another seeming paradox- that of Favors and Eases. These two elements of animation are the primary means to help define spacing (irrespective of timing). Many think that Eases and Favors are the same thing (if they even think of them at all), but if you think about it they really aren’t. Let’s look at why.
Definitions…
Timing:
The time it takes for any object in motion (arm, leg, ball, can of spam, etc.) to go from resting in one position to resting in another new position (pose).Spacing:
How the object in motion covers that distance incrementally from one position to the next. Each new frame shows the object in a new position in two dimensional screen space. The space between where the object was in the previous frame and where it is now in the current frame is the core of spacing. One can manipulate this element to give motion a unique flavor and style as well as the illusion of velocity.Favoring:
When the spacing of the object in motion has a greater number of frames (drawings) that are more like one position or the other then it can be said that the move “favors” that position more.Eases:
Spacing that either gradually increases between drawings or gradually decreases between drawings, specifically toward the beginning and end of the transition. This change defines the incremental acceleration and slowing of motion between two positions.
OK, that probably doesn’t make a lot of sense. So let’s look at some pretty movies! Ok, they’re just grey, but they illustrate the idea.
Example #1: Even Spacing
Here is a ball. It moves from one rest position to another in 20 frames. So the timing is 20 frames. The ball moves the same distance for every frame (1/20th of the distance between the first and second position). Thus the spacing is linear.
Below is a snapshot of the ball’s movement where we record the position (spacing) of the ball for every frame.
(click image to enlarge)
Note the linear, regular spacing (equal space between drawings = linear). This is not very interesting to watch or look at. Now, let’s add some eases to this motion.
Example #2: Spacing with Eases
The timing is still 20 frames. The ball moves from rest to rest in 20 frames, so we have not changed our timing at all.
The spacing is different because we have added the perception of acceleration and decceleration as the ball moves. Here’s a snapshot of how the spacing looks..
(click image to enlarge)
The ball covers less distance the first few frames (less distance covered in the same time, or less space between the drawings = slower). The the ball covers more ground through the middle of the move (greater space between the drawings = faster). Then the ball slows down again (less space between drawings = slower). These slower parts are called Eases. You are either Easing Out or Easing In. Which one is which? Depends on how you look at things. Most folks talk in terms of the poses (positions). Thus the beginning of the move the ball is Easing Out of the first position. Then the ball Eases In to the second position. In case you need to see something in the curve editor to explain the idea, here you go!
(click image to enlarge)
In neither of the above examples have we added any favoring at all. How can we tell? The end of the move covers the same amount of distance in the same amount of time as the beginning of the move. This means that there is no favoring at all. Remember the definition of favoring?
When the spacing of the object in motion has a greater number of frames (drawings) that are more like one position or the other then it can be said that the move “favors” that position more.
In the above two examples we have the same number of drawings/frames where the ball is closer to position A as it is closer to position B. Thus you can have motion that has eases but has no favoring. How? Because Eases and Favoring are NOT the same thing. They are related, but they are not the same. So what does favoring look like?
Example #3: Spacing With Favoring & Eases
Here is another move. The timing is still 20 frames. We have the eases from before, but now we have added a breakdown or two that helps define the favoring.
Here the move favors the beginning pose, or the pose in front of the move. Thus the name front favoring. Here is a graph that might help us CG f-curvy types to see what’s going on.
(click image to enlarge)
What does this look like if we favor the other pose?
The nature of the move feels different. It has a different kind of energy as it is now favoring the second (or back) position. But the timing is still the same, and the eases are very similar as well. We’re just favoring the second pose more. So just by chaning the favoring (but not the timing) we get a very different kind of move. Here’s another graph thing to help explain what’s happening.
(click image to enlarge)
Snap? Yes!
Favoring combined with eases go a long way to adding a dimension of snappiness to a move without it feeling harsh or stiff. So if you ever wanted to know the secret to snappy animation that doesn’t jar your eyes out of your skull, it’s almost all found in the favoring combined with eases.
Can we have a move that has favoring but has no eases?
Sure. It’s not exactly pretty, but you can do it. Here’s how it looks.
We still see from the spacing snapshot that there is a definite favoring, but there is no ease out/in at the beginning and end of the move.
(click image to enlarge)
All Together Now
OK, so let’s look at the mother of all spacing movies. The timing is the same for every ball. The only difference between them is how they’re spaced and this is determined by how we apply favors and eases.
example 4: The Great Comparison
As you can see all the moves have the exact same timing, but the spacing in between for each one is very unique. Some have no eases, some have no favors, others are different combo of both. Favors and eases define the nature of spacing and by in large spacing defines the flavor of the motion (as well as the style in many cases).
So remember, favoring and eases are both related to spacing, but they are not the same thing. You can have one without the other, but together they both effect spacing.
Uses
I’ve already covered the importance of favors for adding snappiness to your motion. Another thing that favoring is useful for is in defining the flavor or style of a move. This movement flavoring helps differentiate meaning to different motions. Let’s use speech as an example. If you think about it there are many ways to say the same phrase, but each way has a slightly different meaning. Let’s take a small phrase as an example- “I was here yesterday.”
One way you could say that phrase is: “I wuhzzzzz hhhhhhhereyesterday.” In this way the person saying it lingers or almost pauses in the transition from “was” to the finish of “here”. And “yesterday” tumbles out quickly. Perhaps this is a guilty person being asked by the police where they were yesterday during a crime. So the fellow struggles to find an alibi, they linger as they try to think of a good one. As they search their mind for a good answer they are slow to get to the word “here”. This is similar to a front favored move. The speaker doesn’t move very far in words for some good amount of time, but then they quickly finish the sentence. So a slow-fast favoring in speech occurs.
Now let’s say that an innocent person is being asked the same question by the police. Their response will be more empahatic. “Iwas heerrrrrrrrrre yesterday.” In this version the person quickly moves to the word “here” and holds it as a way of emphasizing it’s truthfulness. This is like a back favored move. The speaker quickly moves through the first part of the phrase and lingers on the second half of the word “here” for emphasis. Thus you get a fast-slow flavor to the phrase.
Both phrases take roughly the same amount of time to say. They use the same exact words. But the way the speaker emphasizes a different part (by the use of favoring a sound in a word) indicates a very different meaning. Thus is the power of favors in animation. You can take the same move, with the same 2 poses and the same exact breakdown drawing with the same exact beginning and ending timing and just slide the favoring from front to back to drastically alter the spacing (and thus the mood) and meaning of the motion. Kinda cool, huh?
Anyhow, I hope this has helped. No go forth and animate with understanding!
K.Lango
