21 September 2017

How to animate a bouncing ball in Krita

How to animate a bouncing ball in Krita

Probably you have already read the last post about How to animate a ball in Krita from scratch, today instead I will explain you how to animate a bouncing ball in Krita using a different approach from the previous one. We will see also two of the 12 principles of animation: Timing and Spacing, how they are working and why they must coexist in animation.


Let us start explaining what timing is first. Timing is the representation of the speed of an action.
Thinking of a ball that is falling from a long distance, it will takes more than one second to fell.
How long will take the action? How fast it will be? This is the timing. Animation without timing does not exists.

animation of a ball with 24 frames per second
Let us see now how we can apply timing to a bouncing ball. This time we will create a line that will represent the frames of our animation. Let think the duration of the animation of two seconds. One second in this case is made by 24 frames per second. To understand from how many frames will be constituted the timing of two seconds you can apply this simple formula: 24(fps)*2(s) = 48(fps).
As we know where the animation will starts and where ends, we will draw a key frame at the beginning and at end of the respective frames. We will call these key frames from now extremes as they are situated at each extreme of the line that represents the time.

Open Krita and go in File>New>Custom Document and set Width and Height to 800x400 and press Create.

create the new document in Krita

Add a new layer. Double click on it to rename as Timing. We are going to use this layer to set the line who represent the timing of the animation.

the new layer called timing

On this layer we are going to draw a line with the Line tool that helps us how set the duration of the animation. So for this reason, we must write the two numbers that are representing the extremes. Select the 2B Pencil brush, then select the Line tool.

selection of the 2B pencil and of the Line tool

Draw in the middle of the line the number twenty-four. This number indicates the breakdown, in other words, the part where from the first extreme, the animation will suffer a change of action (in this case will represent the change of movement in the other extreme).

our extremes and breakdown

Now from the frame one and twenty four we must set the in-betweens. From the extreme to the breakdown the ball will form a curve. So we need to add a layer called arc where to draw an arc that represents the motion of the ball. However, a ball when is falling is losing height. The gravity will push the ball against the floor. In this case after the ball will bounce, will not have the same height at beginning. So we need to draw the height a bit low after the first bounce.

the arc of the motion

Now we will add inbetweens that will help to set the timing of the ball. Select the layer called timing and add a new number between frame one and frame twenty-four.  After that the ball bounces, we need to set the other in-between that represents the second curve of the ball. We will set it at the frame thirty-six.


You must set a new layer called ball and add two frames, zero and one. Our animation will start from the frame one and it finishes at 48.

Setting the animation duration

 Draw a ball with the Ellipse tool at the first frame and activate the lamp icon for the onion skin. Go on the twentyfourth frame and copy the frame. With the Move tool, move the ball to the line in the middle. Copy the frame at the fourthyeight and set it at the end of the curve. You should get a result like this:

testing the extremes and the breakdown

It is time to add in-betweens. Do Copy frame on the tweltfh frame and to the thirthy-sixth frame. Move the ball at respective positions. You should get a result like this:

testing the in-betweens

To get the complete animation, you must copy each frame of the ball and move at all equal distances with the help of the onion skin.

add more in-betweens

You will get a result like this. A clean animation of two seconds.

our first bouncing ball is ready!


Now that we have understood how to set a timing, it is time to speak about spacing.
Spacing represents the space between each frame. Less space means slow movements, more space means fast movements. Before we said if we put less space between a frame and other, the movement will be slow, if we add more space bewteen a frame and another, the movement will more fast.

this animation has the duration as the previous one but the spacing has been applied

We want that our ball will start with a slow movement then to speed up when is falling for the gravity and then decelerate when is arriving at his height point then to speed up again at the end of the animation.

To do that, we need to decrease the space between each ball with the help of the Move tool.
Duplicate the ball layer and call it spacing-ball. Hide the previous ball layer.

duplicate the ball layer

Duplicate also the timing Layer and call it spacing. We are going to edit the distance of spacing in the animation. We are going to set the timing line like this:

change of the in-betweens

That will give us a result like this:

testing the new in-betweens
 Check now how I changed the space of each frame in the animation. At the beginning there is less space, then more space and again, less space at the end.

changing the spacing

This different setting, will give you a result like this:

bouncing ball with the new spacing applied

Timing and spacing must coexists. We cannot have something made just by timing, it would produces innatural movements and would lose of credibility. Thinking of a bicycle. It would not run at the maximum velocity from beginning, instead it would starts to move firstly slow, then fast.

Let us compare us the animation of one second without spacing and with spacing. Recapping what said before, to animate a ball that is bouncing, we need to specify the time and how to handle the space of each frame to give to our animation a determinate action and/or feeling.

As we have seen, using two of the 12 principles of animation give us the opportunity to animate a bouncing ball understanding how long the animation can last and at which time can be slow down or accelerate.

If you are not a fan of the written-tutorials, here you can find the video tutorial version:

Thank you for reading the article. Do not forget to leave your feedback in the comments area and to share the article on your favourite social platform.

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