Assignment #4: Walk Cycle

Assigned: Thursday, Jan 27th, 2011
Due: Thursday, Feb 3rd at 3:00pm

Resources:


Part 1: Video Reference

Reality is always the foundation on which to start when approaching any sort of animated movement. Starting this week, video reference will become a critical tool that helps you plan and execute more believable motion.

What to do:

  1. Take video reference of three unique walks. This reference should not include yourself or anyone else enrolled in this class. Try to get these walks in their "natural" state. If people know you are filming them because of their walk, their style of movement will inevitably change.
  2. Take reference of yourself doing a normal walk from both a front and side view. Keep in mind that for this particular walk you are trying to understand the mechanics of a walk itself, so try not to get too creative. Just walk as you would normally.

    Study this reference exhaustively. Pay attention to things like the rotation of your hips versus the rotation of your shoulders, how your hips shift and orient depending on where the weight is (from both the front and the side), and how your arms swing.

Part 2: Animating a Walk Cycle

Walk cycles are very important in animation. They are important not just because they are a common type of motion, but because they reinforce many of the motion principles you learned. Squash and stretch, arcs, overlapping action, follow-through, timing, and weight all play big roles. Walks are also a particularly complicated motion with a vast amount of different styles - many with only the subtlest of differences.

Luckily walk cycles have been done so often and are so important that there are already a few established ways of approaching them. Read the section on walks in the Animator's Survival Kit. You will be using what Richard Williams calls the "contact method". A walk cycle has four basic poses: contact, down, passing, and up. Each given step in the contact method starts and ends with the contact pose, coming out to a total of eight poses in one cycle.

It is important to keep in mind that the preceding poses are only a guideline. They should give you a general idea about weight and motion arcs, but what you do within and in-between these poses will determine the style of walk. The reference you took is a version of your "normal" walk, but everybody walks differently.

What to do:

  1. Start by blocking in the contact poses. Use the video reference of your normal walk as a guideline.
    • This involves completing two full steps, after which the animation will repeat. There will be eight unique poses. The final ninth pose should be identical to the first contact pose only with shifted Z translate - this will be essential in eventually getting the cycle to loop.
    • Your character must walk across the screen and not in place. This way you won't have to worry about sliding feet.
    • As far as the workflow, you may find it useful to have the video reference paused in one monitor while you pose the character in the other. Exaggerate details where necessary; don't just do a one-to-one translation (due to differing proportions this would be impossible anyway).
    • Don't neglect the weight shifts and leg positions in the front view! Pay special attention to how the hips are moving and rotating at all times.
    • When you are finished, save out a copy of your Maya file with just these poses.

  2. Add breakdowns and polish your animation. Make sure the motion looks good from all angles (side, front, perspective). Insert breakdowns when needed to help define motion arcs and overlap as you did for the forward jump. Use clamped tangents on the feet so they don't overshoot their animation curves and go through the ground. When you are finished, look at this mini-tutorial on how to make your animation loop.

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