So I was talking to someone about breathing animations the other day and they said they had searched all over the web and not found a single guide showing the proper way to do a breathing animation and I had to hop on the idea and create a simple guide on how to animate it.

Before you read this guide I recommend you already have a steady knowledge of the controls of sfm and how to animate using the graph editor.

Breathing is done in 3 simple steps, you breath in/out then hold your breath for a very short period and then do the opposite of what you initially did (breath in or out). Once you have practised this enough times it can only take several minutes to complete the animation, which means it can be a quick process and save time on parts of your animation which include idling.

If you have any questions about the guide or wish to correct something please leave a comment.

Before you start animating it is best to set up a loop for the breathing animation to save time. Do this by selecting all the bones required:

Do not include the bone between the neck and the 3rd spine as this manipulates the body too much. The pelvis is not necessary if the pelvis moves in your animation, otherwise only subtle moving back and forth is needed, like in all idles.

Once you have all the bones selected, open your graph editor and create a keyframe at the start time of your breathing animation and at the end of the breathing animation, for my example I am using a 2 second loop, I would recommend around 2-4 seconds for a static idle if you were to do a more energetic breathing motion the time would be shorter. After you have the time span set out, continue to make a keyframe in the middle of these two points and then half the two you just made until it looks like the image on the left.

As you can see you have "hold - breath in/out - hold - breath in/out - hold" it has a hold at the beginning and the end as it is a loop.

To start we need to move our playhead to the 1st keyframe within the loop. An easy shortcut is using the "[" and "]" keys to flip back and forth between keyframes, and this also means you don't click before or after the keyframe by mistake. See below.



After we have selected this keyframe we now need to start moving the bones to their correct places. First of all select the rotate tool as it is more accurate than the screen tool. Then we need to rotate the first spine bone backwards slightly, make sure you do not overdo the rotations as it will look to energetic and crazy. To help with this go by the guideline that it wants to be rotated but not have a gap between the two rotation bars, see below for a reference.


We now need to do the same to the other two spine bones, but instead of rotating backwards we rotate inwards to create the illusion that the middle of the body is being relaxed like you do when you breath out. See below for all the reference images.



I tend to not move the 3rd bone if I want the movements to be more subtle, but it can be useful in some cases.

The holding point is generally the same as the original pose, so does not really require any change, but it should be the 2nd keyframe here:

Breathing in is basically the opposite of breathing out. When you inhale your lungs are filled with air which means that your upper body expands and your belly area is pushed outwards aswell. We can create this illusion by rotating the bones like before. Select the 3rd keyframe.



First we rotate the first spine bone fowards slightly. This also needs to be more subtle than breathing out as your belly does not move as much when breathing in.



After this we now rotate the second spine bone backwards, this should be around the same amount you rotated the first spine fowards.



Finally we require to move the last spine backwards. This part does wants to move more than the other spines as your lungs increase in size quite a bit.



Your animation should now look something like this:

These details should only really be applied if the animation is an idle.
For a start the neck wants to stay in a similar spot. We do this by marking the head of the neck with an application such as 'Epic Pen' when on the holding keyframe and then we make sure the neck's head is always in the same point. Do this for the breathing in and out keyframes.



This is how your splines should look like when you are done:



Also if you find some stuttering in the animation, select your scout model in the animation set editor, then select all the keyframes in the graph editor and press 3 to re-spline them.

If you also want to improve your idle you could involve subtle mouth movements, or nostril movement if you have the flexes for them.

Thanks for reading and I hope this tutorial helps.

If you enjoyed this guide please rate it up and favourite, if you didn't please tell me what you disliked about this guide so I can improve it in the future.

If you also have any topics you would like me to talk about please tell me.