LESSON - Animation Loops (Patreon)

In this lesson, I’ll explain the thought process of how I did my animation loop. I won’t be doing a full step-by-step process, but rather I’m highlighting the key concepts that make the animation look good.

I’ll be using some terms from the 12 Principles of Animation, and I’ll try to explain them whenever they come up. However, if you like, you can use this video by Alan Becker as a primer: https://www.youtube.com/watch?v=uDqjIdI4bF4

DISCLAIMER: I'm not an expert in animation, so I might use certain words or terms incorrectly, apologies in advance. This lesson is only for giving you basic knowledge on how to do a simple animation loop.

I start with my static sketch:

Because this is a loop without any fancy camera movements, I can simply use this one sketch and work my motion based on it.

Now let’s get to animating!

Primary Action

First, I think it’s good to determine the Primary Action, which is basically the focal point of the movement. In something like a walking/running cycle, the Primary Action is gonna be the legs. In something like a punch, the Primary Action is gonna be the fist.

In my case here, the Primary Action is the top’s pelvic thrust. Everything else, like the arms swaying, the bottom being pushed around, etc. will count as Secondary Actions.

I’m gonna represent his pelvis with this shape here.

You can use a circle if you want, but I find that using something slightly more defined like this will help to visualise the motion better, and it translates to the final animation easier as well.

Mapping Out Motion

Here, I start to build the loop. I’m doing a very short loop so I’m aiming for 5-8 frames.

To start the mapping out process, I have to determine the motion of the thrust. Do I want it slow and gentle, or do I want it fast and forceful?

You can play around and see what they look like. For example, slow and gentle would look like this.

Tender, almost like he’s only teasing instead of actually pounding.

And here’s the arc of the motion. I placed a dot just to track the movement.

Here, I’m using the concept of “Slow In - Slow Out”. This basically reflects how the momentum of the torso is gained AND lost gradually, i.e. the fast impact starts with a slow build up, and ends with a slow fade-out.

What about fast and forceful?

I’m using fewer frames here, only 5 compared to 8 in the slow one above. This is simply because the movement happens faster, therefore less time, therefore fewer frames.

Let’s look at the arc.

Here, I’m still using Slow In - Slow Out, but I’m also using the principle of “ Anticipation - Overshoot - Settle”

Anticipation is when the object is building up power. 

Overshoot is when that power is released explosively, and actually shoots past the target point. 

Settle is when the object comes back to a resting position after releasing power.

This principle is usually more prominent in high-energy actions, like jumping or throwing a punch.

HOWEVER, Whatever you do, do NOT use a uniform motion.

Doing it like this will take away any chance of making it look life-like. Only robots move like this.

---

In any case, I ended up going with something in between. 7 Frames, so a bit slower, but with a pretty strong impact.

I added a hold frame, where the pelvis barely moves for 1 additional frame after the impact, to really sell that WHAM motion.

Once I map out the motion, it’s time to draw the actual body!

K.I.S.S. - Keep It Simple, ------!

The actual saying is “K.I.S.S. - Keep it simple, stupid!”, but I don’t think any of you are stupid ksgjhds

So just Keep it Simple!

Here’s an example.

Something like this will give you a MOUNTAIN of problems. The abs might look janky, the nipples might jump all over the place, etc. etc. etc.. 

Trying to fix all of the tiny little problems over several frames will be a NIGHTMARE.

Just omit all the muscle details for now and draw the silhouette. You can add details back in later.

Here we just have the silhouette. A lot simpler!

But if you look closely, there’s still lots of tiny little line details that will cause you problems, like those abs and the nipple for example.

Simplify it further!

This may look very plain, but it’s actually extremely advantageous for animating.

Remember, You can add details back in later.

For now, look!

You only have to worry about 8 lines! 

Even if you have to do a bunch of fixing, fiddling, and redrawing, it’s only 8 Lines. Significantly less work compared to the nightmare we have in the beginning.

From there we can start making it move!

Even with how simple that is, doesn’t it look beautiful already?

Now that the Primary Action is drawn, let’s move on to Secondary Actions. This calls for applying another set of principles, Drag and Time lag.

Drag / Time Lag

Drag usually refers to how appendages tend to lag behind the main, moving body. Here’s an example from the 12 Principles video: https://youtu.be/uDqjIdI4bF4?t=581 (timestamped).

The concept of Drag (or follow through, or overlapping action) will apply to some parts of the body. In this case, maybe the arm or the hair, or some other parts, but I won’t delve too deep into it in this lesson.

Aside from Drag, there’s a similar but different concept. 

It’s something I like to call Time Lag, which happens when two objects transfer motion into each other. In our case, the top’s pelvis transfers motion to the bottom’s pelvis.

Before I explain in detail, here is the shape I’m using to represent the bottom’s pelvis.

And now to map out the motion, you might be inclined to follow the exact same motion as the top’s pelvic thrust…

...It ends up looking a little mechanical. Kind of like train wheels rotating in sync with each other, instead of, ykno, intense pounding.

What we need here is the Time Lag. Essentially this means the bottom’s pelvis moves 1 or 2 frames late compared to the top’s. Something like this.

And here’s the arc of the motion, numbered so you can see the time lag.

The top’s thrust happens at frame #3, but the bottom bounces forward at frame #4, i.e. he lags 1 frame behind.

All there’s to do now is to add a biiit of squish during the impact at frame #3

And that makes the animation just go 1 step further at being lifelike.

Now to skip ahead a little bit, I actually applied the same concept of time lag to the body as well.

If you take a closer look, the front part of the bottom’s body (i.e. the shoulders in this case) lags 1 frame behind the butt bouncing.

Here it is again in slower motion

This technique is crucial if you really wanna make a lifelike animation loop.

Conclusion

Creating a good animation requires a lot of thought and planning. I definitely recommend to take your time in planning the movements.

Don’t rush, because it’s a LOT easier to prevent problems than it is to fix them if they already happened. 

The last thing you want is to have to redraw the body 20 times because you didn’t take time to plan the movement properly. Think of your poor hands!!

Repeating what I said in the other lesson, I’m not an expert animator, so here are a couple of recommendations for further reading:

• 12 Principles of Animation illustrated by Alan Becker (creator of Animator vs Animation): https://www.youtube.com/watch?v=uDqjIdI4bF4
• Animation Tips by Toniko Pantoja: https://www.tonikopantoja.com/tips

---

As always, if you have any questions, feel free to hit me up in the Art Labs channels in the AA Labs discord!