Play back the animation. What are some problems that you see? What makes it not feel realistic? Can you see if the ball is hanging on the arc too long? How does it feel to see the ball move at the same speed all the time? Is it going fast enough when it hits the ground? Does the movement slow down and fade away naturally?
These are all questions that you should be considering as you test animate. The goal is to see how well you understand how to animate movement and see if you have an idea of how to manipulate this movement in a believable way that looks realistic.
Now let’s look at some terminology that will help you better understand what’s going on. Timing is what determines how long a given action should take (how many frames). The spacing is how far an object should move from one frame to the next (how much space between drawings). You can take the very same drawings and space them different ways to get a very different result in terms of acceleration, rhythm, weight and speed.
For a simpler example that will demonstrate weight let’s look again at the bouncing ball. We will animate the ball with the same poses and the same path, but with different timings and spacing. It’s not necessary to complicate things by having detailed characters. A simple bouncing ball will do to demonstrate this principle.
First we’ll draw them all apart:
Now we’ll tighten things up: We’ll bunch them together on top of the arc (this will slow the ball and create an ease-out at the end of the movement just before it reverses direction) and tighten the timing near the impact on the ground (this will create an ease-in just before it reverses direction). Notice how the frames are further apart the closer the ball is to the ground, which will give it a feeling of acceleration. This is what happens to a ball that is dropping due to the force of gravity, because the frames would be evenly spaced if we were animating a mechanical movement, and this will feel uniform, not unlike the constant speed problem that we had above.
Let’s try both at the same frame rate:
The only difference between these two is timing/spacing. Which one is more realistic and why? Which one has more weight?
The importance of timing and spacing is hard for the beginner to understand at first. Often the urge is to add more in-between drawings to an animation if it feels too rough, but these drawings are not just added at random. Often adding more in-betweens may result in softening the movement and in some cases slowing it down, the opposite of what you are trying to do!
The first step to understanding timing and spacing is to get a feel for how you are distributing frames in an animation. When you look at the drawings on the screen they may not be spaced evenly which is good; however it might be that you didn’t intentionally space them – they just randomly fell that way! Using onion skin will help you to see if they are too evenly spaced. Once you are looking at the whole animation at full speed it will be easier to see where the frames are not clustered together or spread apart where they should be.