Animating a Jump

In this tutorial we will make our animation doll jump from the purple block onto the blue block.

Jumping gives us a very good example of how energy is put into a motion and how the energy is dissipated from the motion.

As for our previous examples, we will adopt a four phase approach.
1) Keys (the story)
2) Extremes (the motion)
3) Breakdowns (the energy)
4) Straight Throughs (the character)

1) The Keys
Before you start setting keys, make sure your keys are set to stepped.

Start by putting your character in a standing position, with the body posed in a way such that it looks like the character is thinking about jumping (frame 0).

 

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The second key piece of information is when the character lands (frame 20). This is a key because it determines what kind of jump it is and this will thus in turn determine the nature of the extremes and the breakdowns. ..

2) The Extremes
The next thing we need to do is describe the motion. How high does he jump? How much does he crouch before jumping? How much does he have bend his knees to receive his momentum when he lands? Essentially we have to map out the extreme ups and downs of the jump here.

The initial down pose. Because we are using stepped keys, we can move to say frame 4 and lower his pelvis without loosing his original footing.

 

The final down pose. You can move to frame 20 and then middle mouse drag back a few frames such that the final down pose footing is the same and the final standing pose.

 


The extreme top pose. Now with both down poses keyed in we can key in the top of the arc. The weight comes from the pelvis and the pelvis follows a parabolic curve. As the body reaches the top of the curve, to increase momentum, the limbs must pull in towards the body.

3) The Breakdowns

To create the breakdowns, we will first establish the poses of the breakdowns, and later when we are satisfied with them we will work on their timing.

In terms of energy, we need to express the energy going into the jump (anticipation), the energy of the jump itself, and the dissipation of the jump's energy (follow through).

First we can create the energy poses of the actual jump. We will start to develop our breakdowns in the same way as we did for our run. The pelvis will still follow the arc described by the extremes. To start, just key in the pelvis motion (making sure to RMB drag back from the final down pose to conserve the foot placement).

   
We can pose our character a bit better now that the pelvis is in place. Remember that these poses express the energy of our movement. So the first peel-off breakdown is thrusting the weight upwards. The contact pose on the way down is balancing the weight so the character doesn't end up falling flat on his face.
   

Now we can add in an anticipation pose and a follow through. Note no timing of frames has been done yet. The anticipation pose swings back to develop some locomotion. The follow through pose extends the momentum of the arms and pelvis downwards.

 

Our jump is starting to look believable, but the timing is still too robotic.
Now we need to work on the timing to give the character its weight. Currently all our keys are equally spaced. Below these keys we see the redistributed keys that take into account the relative time for energy of the jump.

In terms of the energy and timing, to get over such a big gap, more anticipation is needed to put more energy into the jump, followed by a quick thrust upwards, gravity and parabolic motion follow, the momentum forces the body into the follow through for a similar time as that of anticipation, until the momentum dies down enough to rebalance and stand upright again.

4) Straight Ahead

Now for some character. At this stage you can add as much crazy keyframing as you want, as long as you don't change the timing or pose of the existing structured keyframes.

Its up to you what you do with the straight ahead sections. For this animation I will add some fidgeting prior to the anticipation, and then some balancing movements as well as some checking of the ravine after he has jumped. Here is the final animation from two perspectives.