Tuesday, January 4, 2011

Can You Provide Some Tips on the Mechanics of Walking?


A walk is such an easy thing.

An easy thing to screw up.

Too much overlap on the swinging arms. Too much bobbling up and down. Too much head sway. Those are a lot of distractions!

Let’s focus on what is going on in the body. One leg is pushing off the earth and moving forward to make contact and propel the body forward. (Can you tell I took physics in college? I didn’t pass, but I took it.) What the foot does then is capture the weight of the body to make sure its owner doesn’t come crashing to the ground.

That’s essentially it – as far as the legs go. It’s a fall. Every single step. After that foot crosses the magical midpoint of the center of gravity, that big old body wants to fall. Mr. Foot connected to Mrs. Leg has to hurry up and make sure the body doesn’t fall, so it has to hurry up just a bit to get in front of the body and stop its fall.

So there’s the silly explanation for what happens. How can you put that into practice? Something I do all the time is observing people. I love to go to the airport (no, not to just hang out) but to watch people get from one place to another. What do their feet do? How do their hips rise and fall for each step. Just how much swing is in their arms? I study and learn.

Then I put it in the computer. A long time ago, I used to do mechanical exercises in the computer by using a layered approach to animating. This goes against all that’s in my fiber of being now, but I used it strictly as a learning technique to understand force, momentum and balance on a walk (it was actually a skip for Captain Hook). What I did was took his COG (center of gravity) and translated that in space. I made him feel like he was walking (I know I said skipping, but I’m stretching the truth to make a point). I would then add a little bit of rotation. Get that momentum going up and then have a nice overlap as the foot would hit (even though I didn’t animate that foot hitting yet).

Then I would go up the chain – mid body, upper body, neck, and head. I would add some twist on the body so it would go the opposite way the hips were going until the shoulders were completely the opposite of the hips.

Next would be the legs. At first, I would do ONLY the steps, no transitions. I would keep this in stepped mode too. It would look funky to the outsider but to us abnormal folk (animators), it looked fine. After I got this placement correct, I would add my spacing for the feet. It takes the foot longer to get to the transition (the passing pose) than it does to the impact.

Arms would follow and so on – you get the picture.

My point?

My point is, I got to feel how EACH part of the body FELT during the walk. What were the hips doing? How much opposite were the shoulders? Just how much x rotation was needed? All of this was answered by doing that little exercise. By doing that, I gained knowledge of what goes into a walk.

Sometimes you have to do the grunt work to get the good stuff…


Guest Blogger Mike Gasaway