Similar to our conventional walk cycle, Richard Williams also provides us with a solid formula to work from:
I thought this would be an interesting kind of walk to attempt to emulate with the Moom character, especially with all the bending and twisting going on in the torso. I find the arms quite interesting too, I love the way they're posed almost timidly. They remind me of a little hamster! I think it would be possible to get some really nice head and wrist movement with this walk.
To save myself a great deal of stress, I decided to adapt this formula for my characterised walk cycle. Just copying the frames is no good by itself though, it doesn't really give you any indication of the timing or any real sense of the weight. Observing and performing the action yourself is always the best way to go.
There's a disappointing lack of reference footage online for this particular sneak, but I did find a short clip from the DVD set that kind of demonstrates it:
It's not brilliant but it does serve to give you more of an idea about how the weight shifts in relation to the movement of the legs and so forth.
I also did a sketch of the key frames from the diagram - it's pretty much just a carbon copy but I found that having to draw the poses myself gave me a much better understanding of how the body was poised, how the hips were tilted, where the weight was, etc. Even if you're just copying it's always good to draw things yourself - it gets you actually thinking about the mechanics of what's going on.
Following these examples, I started blocking out the walk cycle using Softimage's "stepped" interpolation method. Being able to set up and view the key poses without Softimage's rather distracting automatic keyframes. It allows you to much more easily check the flow between each pose and quickly see where things don't align.
Getting the poses right was actually a lot trickier than I originally anticipated. Due to the way the rig is set up it's really tricky to try and get the curve in the spine just right — I tried all sorts of methods including some ridiculously over-complicated method involving translating his chest object to bring it in line with the hips, but it just looked weird. Ther doesn't seem to be any way to adjust how much he leans forward with this rig — tilting the hips and chest does not re-position his upper body at all, and translating his upper body control moves his entire body. As a result he doesn't lean forward quite as much as I'd like, but I think it's looking okay.
There are also some slight issues with the foot slipping around — his back leg goes back too far on what I think is the passing position, when he leans forward. It needs to stay stationary to give the impression that he's pushing himself forward.
Switching to splined interpolation allows us to see that his foot definitely slips back, and there's also a bit of a weird 'bump' in his torso around one of his contact positions. I think there's a stray translation keyframe in there somewhere that got left behind.