Principles of animating a Bouncing Ball - 4

In-betweens

The last step is to do the in-betweens. In-betweens are the drawings/frames between the key frames which help to create the illusion of motion.

When doing the in-betweens using traditional animation you need to remember to transform the ball from its round shape to move of an oval shape but using 3D such as Maya it will do the in-betweens for you but you will need to use the graph editor to make sure the ease-in and ease-outs work and that the ball is stretching along the arc and that the transitions work. Your ball bounce with in-betweens should look a bit like my drawing below on the right.

The best way to work out your animation is to PLAN! You will hear this over and over again but planning is very important. It may seem at the time like you know what you want and can skip it but trust me when it comes to it you will end up animating and reanimating until you end up doing the planning any way.

Below is the ball bounce that I made in Flash to show what the final thing should be like. Sorry that its poor quality. Something that happens in the uploading to blogspot I think.

Principles of animating a Bouncing Ball - 3

Squash and Stretch

Now onto something you hear a lot about in animation - Squash and Stretch. You also see it in the real world (a funny picture of this is shown on left). Actually the starting place of learning about it for all animators is with a bouncing ball. A basic explanation of it is that the ball is round at the top of an arc and as it travels it stretches as it speeds up and when it contacts the floor in squashes and as it bounces back up the next arc it stretches again and then back round and the cycle continues until the ball comes to a stop.

To start doing this use Key Poses; for our bounce it is going to be when the ball is a circle and when it squashes on the floor as you can see in my drawing on the left. This is all done to give the ball weight and is very important but you must make sure you keep the same volume area when squashed as it is round.


The speed the ball is going also depends on the amount of squash you have; in other words the faster it's travelling the more squashed and stretched it will be. I made the image on the right to explain this with squash on top and stretch below.

Next up you need to add the stretches which are the main breakdown drawings/poses, in a sense they are really in-between drawings that explain the action the ball is making. In-betweens are the poses that are between the Key Poses. Below is an update of the image I made with the Break Downs added in yellow.

As you can see, the marks we have used so far have all been in the centre of the poses so you can now see how they came in handy ;)

Any way, back to stretch; unlike with squash that mainly shows weight, stretch shows the speed a ball is moving although you do also need to take in its weight.


A great blog that has some posts on Squash and Stretch is HERE. It has some great examples and really explains what it is and its principles so if you want to know more I strongly recommend visiting it.

Principles of animating a Bouncing Ball - 2

Slow-In and Slow-Out

The next principle of animating a bouncing ball is Slow-In and Slow-Out. This is the action the ball takes on the Path of Action. In the case of the ball, the beginning of the arc is called Slow-In and after the ball does its bounce it goes into Slow-Out, this is because it loses some of its momentum so slows as it approaches the top.

A great tip I was recommended to do when planning your Slow-In and Slow-Out is to put marks along the arc so you can easily work out the balls position and timing. For Slow-In you want the marks to be quite close together and gradually have more space in-between and then the opposite of this for your Slow-Out. Here you can see I've added some marks to my drawing to explain this.

REMEMBER - The closer together the marks are the slower it will move!

Principles of animating a Bouncing Ball - 1

Carrying on with arcs I will present to you my research on how to animate a ball, one of the first places to start animating and is made up of arcs! It does also use some of the other principles such as timing, slow-out, slow-in, squash and stretch.

Path of Action

Firstly you need a path of action. This is where the ball will bounce and is just arcs. We will just focus on doing one bounce for now as once you know how to do one you can do more.

If you wanted to do more bounces, the arcs would need to stay in line like the red line shows with the arcs in the bottom drawing on the left.

Fixed the ball

I fixed my ball. I noticed that the ball was stretching too early and that the bounces were like it was heading into wind so I checked the graph editor and i had forgotten to make the stretches ease in and out so I did that and noticed a missing stretch so fixed that too. I then changed the bounces in the graph editor too so now I think its lots better. Below is my 1 ball bouncing from a side view and below that is with a copy of it imported into the original but at a different angle so you can see both balls.

Please comment if you notice anything I have missed.

Some comments from my classmates

Charlie - Nice job Emma! Couple things that I noticed:

1. Turn off the grid for your playblasts, it'll make things easier to see.

2. Zoom the image in more. Don't forget you can Alt, L, M, and R buttons to make it fit better. You want to be as close to the action as possible to see it clearly.

3. For now I'd take out the stretch and squash and get comfortable with your timing and spacing. Remember each bounce the ground is taking away some of the energy from the bounce so it shouldn't keep bouncing full force.

4. The ball speeds up pretty fast then suddenly slows down as its traveling across the screen. It should gradually get slower along the way.

5. Each subsequent bounce should be around 70% less than the previous one give or take. Bow your curves out on the graph editor and break your tangents for more control.

Love how you thought outside the box by having the ball bounce down the steps, nice thinking! Good luck!

Marcelo - Nice!

Just watch out ball skidding on frame 94.

Said also did this drawing on top of someones work to explain how a ball should bounce. I thought I'd post it as it will be helpful for people who read this blog and myself in the future.

2nd attempt at the stairs

Well, here is my second attempt. I think its still slightly not right but Said did say that we don't need to do squash and stretch yet so I think I will just import the second ball tomorrow and move onto the Robot Arm! I've been looking forward to animating that any way :D

Ball Bouncing Down Stairs & Critique

I decided that I would make my bouncing ball more interesting so I animated it bouncing down some stairs. You can see it below.

I knew somethings weren't right about it but as I ran out of time I still showed what I had done to Said during todays Q&A and he had some points about what I did wrong.

Firstly a ball goes into a bounce quicker than it comes out so I need to move my first stretch of a bounce back a frame and not stretch the ball so much on the bounce out. I had thought that might be one of the problems but as my Q&A was starting I needed to upload what I had. Its good to have my suspicion confirmed too :)

Secondly, my bounces are too sharp. Said drew on my animation to explain what it should be like (See left), this was another thing I had noticed and was planning on changing. I'm thinking of missing a step too as it's unusual for a bouncy ball to hit each step. It speeds up a bit and goes further before it slowly bounces to a stop. Even Said in his drawing suggested this.

Thirdly was the view. Although I had planned on doing what Said had said but as I was uploading it quickly so just used the view I was in. Said said that Mentors can get annoyed when a ball just starts from the sky and doesn't roll to a stop or just go off screen. So I need to change it so its looking at the stairs sideways on, put the ball so it starts off frame and make it roll to a stop or roll off screen. Also, change the stretches and jump spacing.

Another point Said made was PLANNING! We were told that we must plan animations before we do them. Which, yes I know... if I had planned out my animation using thumbnail sketches I would of realised that the spacing was off and also the ball stretches so I have learned my lesson to not try and cut corners by not planning. Its actually going to take me longer to fix my mistakes than it would of taken me to of planned it first.

Graph Editor & Bouncing Balls

So we are in Week 8 and this week the is again 2 assignments. The first is to make a ball bounce and to do this I had to use the graph editor a lot. I did at first use the ball rig we were given but for some reason the was no squash or scale controls in the channel box so I started again but this time I used a ball rig I had gotten from the online Escape Studios course I did as it has squash controls. It is quite a lot different to the AM rig as I find it easier to control as Escape put handy control handles on the ball. You can see the difference in the image below.

Any way, after we had one ball bouncing, we had to save it as another name and then import one of the ball bounce files into the other so I then had a second ball doing exactly the same thing. But the second ball needed to bounce a little different than the first so I had to change it. This class really taught me a lot about the graph editor and what it does although I had learned it before it was good to have a refresher and to find out a few new things.

What my graph editor looks like after one bounce (with Translate X & Y selected)

The reason the is a tiny bump in the middle is because I was taught in my Escape course that it is better to make your ball be forced to touch the floor on the frame before it lands so in this case it landed on frame 10 so I forced it to the floor on frame 9 by key framing the Translate X & Y to 0 but with the stretch still on but then still squashes on frame 10. It did mess up the path but I fixed this by using the graph editor and making it look like it does above. This just makes it easier to read the squash on the floor. As you can see in my video below.

What my graph editor looks like after four bounces (with Squash Bottom selected)

What my graph editor looks like after four bounces (with Squash Top selected)

And here is what my four bounces looks like.

1st assignment where I get to animate!

Wooo! I've been really looking forward to starting an animation assignment and here it is this week :D Although it is very simple. The first assignment is to just move a ball around to show you can use keyframes and do playblast's. I've done this just quickly but I might have a play with it and make it more fun. Maybe, create a Quidditch pitch and have the ball as a bludger that flies around and scores a goal. Any way, here is my first attempt at this assignment. I know its not right but as I said I will have a play later to make it better.

Our second assignment is to create an animation of a ball moving in a circular motion using the ball model we were provided and to remember to select and set keys on the Control Curves in the graph editor ONLY! Below is what I did. I put a circle curve in front of it to show it does do a circle.