Animating walk cycles: biped walk

In this post I will be discussing how I animated the walk cycle below.

Step 1:

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Draw the two contact positions. Right leg forward on the first and left leg forward on the second. Don’t worry about the arms for now, we will add them later. Note that if you want to animate the walk in place as I did then the second contact would be positioned directly on top of the first.

Step 2:

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Now add the key poses between the two contacts. The top image shows the drawings spaced apart so you can see what is going on, but again, if you are animating in place the frames should be layered on top of each other as shown in the bottom image. Note that the head should Move in a linear up and down motion (a slight curve is fine but avoid circular motions as this can give an odd bird like effect) and the stepping foot should move in an arc.

Step 3:

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Now it’s time to add the inbetweens. The timing chart above shows the positioning of the inbetweens, the key frames that we have already drawn are circled. The speed of a standard walk is about half a second per step, so 12 frames when animating at 24fps (frame 13 is the start of the next step)

It’s important to take care that the foot follows a smooth arched trajectory. The easiest way to do this is to pick a point on the foot (I used the heel) and actually draw the ark through this point on all the key frames, then when you add the inbetweens make sure the heel is always positioned exactly on this line.

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The image above shows two different ways to animate the foot. There is nothing wrong with diagram 1 but it can look a little stiff. If you drag the foot as shown in diagram 2 it will give the animation more flexibility.

Step 4:

You have now animated the character taking 1 step. To animate the second step you need to follow the same process again but this time starting on the opposite foot. When you are done the animation should start and end in the first contact position.

Step 5:IMG_1232

 

Now we can add the arms. The above image shows the key poses for a swinging arm. Our walk starts with the right leg forward and left leg back. The arms should be the opposite, right arm back, left arm forward. Instead of just having the arm straight on frame 7 you can “break the joint” so it bends the wrong way, since it is only bent this way for one frame (don’t bend it on any of the inbetweens) the viewer won’t register it but it will give a feeling of flexibility to the animation. You can also drag the hand like we did with the foot.

Step 6:

Fill in the inbetweens for the arms and you’re done!

 

 

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