Brendan's Bouncing Ball Lecture


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Dragon Walk


To show how useful this theory is I’ve selected a couple of examples of my work where I’ve incorporated what we’ve just looked at. I’m not suggesting theses examples are brilliantly animated but they do show how this can be applied.

As you can see this dragon walk cycle uses the three body masses offset in a similar way to our bouncing balls. The chest is offset from the hips by about 6 frames, and I’ve put drag and follow through on the wings and tail. You'll notice that, unlike our walk, the head rotation leads the vertical movement instead of overlapping it. This is to give the impression of the creature putting more effort into the walk.

Squirrel Run


Here’s a squirrel run animation I’ve done, this movie shows the cycle from a ¾ perspective and, above, the same animation travelling along the ground.

Squirrel Run Profile


You can see when we look at the profile view of this animation how the ball motion has been incorporated in this cycle. This time the head leads with a one frame offset on the chest, then a 2 frame offset on the hips. The gaps in the falling balls have been pushed as much as possible, especially in the hips. And the tail has been used for drag and follow through.

I chose these two example as they make an interesting comparison. The Dragon is obviously an imaginary creature, and there is nothing alive today that we could use as reference for it, bipeds of this size died out millions of years ago. But, facing this problem, it's possible to rely on what we've learnt from the bouncing ball to get some thing that looks convincingly heavy and moves fluidly.

The squirrel, on the other hand, is a real animal. But to simply rotoscope live action footage of a squirrel would be a mistake. Whenever live-action is simply copied, the weight and fluidity of the action is lost. You should always strive to exaggerate or caricature motion, even when you’re trying to create realistic animation. And you can use the bouncing ball principles to inject life, weight and fluidity back into reallife motion.

So, even though the two creatures are totally different the bouncing ball can still be applied to both.

5 Frame Bouncing Ball


That squirrel run cycle was created in animation development for Charlie and the Chocolate Factory. We had to create a library of cycles, some running slower, some faster, walking cycles, burrowing etc. I decided to try to use this bouncing ball theory to create the fastest run I could.
If we go back to our bouncing ball, I've created the fastest bouncing ball possible. It still has 2 frames at the bottom but only 3 at the top. If we were to try and go faster and have just 2 frames at the top we would lose the difference in timing and the animation would look like a sewing machine.

5 Frame Squirrel Run


Here we can see that I’ve now applied the vertical motion of this bouncing ball to the squirrel. I have to admit that this cycle on the spot isn’t very easy on the eye, I’ve had to use some rather ugly poses to maintain our bouncing balls ...

5 Frame Squirrel Run from Afar


... but once we see the cycle as it will ordinarily be viewed, moving along the ground in a long shot. It works and we have achieved the fluidity and weight we were after.
It is worth noting that this is not the fastest cycle we could create, in animation books, like Richard William’s, he shows tricks to creating even faster cycles, but this is the fastest you can go using the bouncing ball.

Walk with Jaw


Here’s our walk cycle again, and now I’ve added a jaw, with the bouncing ball spacing, it's offset further and follows on from the rotation of the head. It’s not normally advisable to have the jaw opening this much during a walk cycle. I've done this to explain a technique of animating dialogue while the character is walking.
The trick comes from the old Disney animators and is this - choose the accents you want to hit in the dialogue, find the frames where the mouth will be at it's widest and work backward through the animation so that the movement of the jaw follows on from a footstep in the walk. So, the foot hits the ground, then the body drops, then the head, then the head rotates down, then the mouth opens at the point of the accent in the dialogue.
It's a technique that some of the old Disney animators used their whole careers and it still always works well. In fact it will look wrong if you don’t do it this way, if the mouth opens as the head is in movement, instead of waiting for the downward movement to finish, the mouth will look as if it's fighting against the action of the head.

Walk with Eye


I’ve now added an eye blink to one of the steps. Even this small touch adds an extra level of weight and life.
The eyelid also follows the same principles as the bouncing ball, and often should. This is not as important in long shots, but in close-ups, if you follow the bouncing ball spacing - starting with the eye open, cushion out to a big gap, then hold it closed for 2 frames, then a jump back up and a cushion in – you’ll get a very powerful blink.

Walk with Arm


Unfortunately I didn't have the time to animate this arm as well as I'd like, the idea I'm trying to show here is that bouncing balls are not always vertical. Here the ball moves on a curved horizontal path.
Hopefully you can see that you can continue to add more body parts that are bouncing balls and are further offset. As well as adding more drag and follow through, and you'll maintain the feeling of weight while giving your animation more life and fluidity. And hopefully I've shown that by using the simple bouncing ball as a building block you can create something more complex but still maintains the weight and life of the bouncing ball.



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© Brendan Body 2008