Join Dermot O' Connor for an in-depth discussion in this video The poses: Contact, down, passing, and high point, part of 2D Animation: Walk Cycles Basics.
- The walk cycle is built from four poses; the contact, the low pose, the passing pose and the high pose, after which we walk back into the contact pose. In the contact pose, the tip of the front heel contacts the ground. In the low position, the leading foot is completely flat on the ground. The passing pose is the midpoint between the two contacts, and the high point is the peak of the walk, and then finally we walk back into the next contact pose that completes the first part of the cycle. Sometimes you'll see the low point referred to as the recoil but I think the calling it the low pose or the down pose is clearer.
Now, in this image I removed the arms so you can focus on the legs. I've shaded the far side to make the action easier to read. Notice the red and blue lines on the ground which show the path traveled by the left and right feet, and I've colored the blue for right and the red for left. It's important that the feet are aligned to these lines, or they'll seem to float above or slice below the ground plane. Now let's add the arms. Notice that when the right leg is forward, the right arm is back and vice versa, and this is called an Opposing Action, and it applies to most walks and runs.
The arms oppose the legs to maintain balance, and notice that the arms are at the most outstretched from the body in the low pose, not on the contact. So to notice this, you'll see here is the trailing arm on this side, and notice how it's bounced a little further out from the body, and it's also a little bit higher if you follow the mouse level across there. Here is the entire walk, seen in the side view and the front view. So now I'm going to overlay the arc path of the head and the upper body. And in this case, it's a very gentle motion, but this is just enough to keep the walk from seeming angular or mechanical.
As long as the arcs and the spacing have been structured correctly, you should see something that looks like this. This is our basic introduction to the four poses of the walk cycle, the contact, the low, the passing, and the high, and the sequence in which we create them. Contact, passing, and then the low, then the high. Let's get very familiar with them as they're the essential building blocks of every walk cycle, so with that we'll proceed to timing and frame rates, and it's a little technical but not too difficult.
Bear with me and I will wrap our heads around these principals.
First, he reviews the poses—contact, down, passing, and high point—and the creative decisions you have to make about timing, frame rates, and placement. (Traditionally, walk cycles can be animated in place or across the screen.) In the following chapters, Dermot animates a character walking in profile and also from a front view. These two projects give you opportunities to see animation techniques, such as creating poses and in-betweens and troubleshooting arcing and timing issues, in action.