What exactly is a walk cycle???? Well in quite simple terms, if you look at someone walking you realise they are simply repeating the movements over and over again as if they were on loop so the walk cycle covers from the first step right the way back to that same step.
How the walk cycle came about is unknown to me but I know of one man who may have helped to understand walk cycles. This man was Eadweard Muybridge (April 9, 1830 – May 8, 1904) whose work has been referenced by animators and artists for decades.
Using a device called zoopraxiscope he managed to film a horse galloping and using the stills he could put it together to create the effect of the horse galloping.
When it was put together by Muybridge it produced a motion picture which we would call a video now of a horse galloping...
Here we see how stills can effectively be used to produce a cycle. This is the basis of the walk cycle can be made. There have been many references to the walk cycle and many animators have their different techniques to create the cycle. Here is an example of how legendary animator Preston Blair describes the walk cycle amongst others in his book Advanced Animation...
As Preston Blair was an animator at Warner Bro's and worked on the Looney Toons characters, he used SQUASH AND STRETCH at a very cartoony level with very exxagerated bounces as the character walks along. The use of EXXAGERATION and ANTICIPATION is very heavily used by Blair and we can see this in all the characters. I really think this cartoon style matches the wackyness of Looney Toons and that if the animators did it in a more literal way it would not have the same impact as it does. As Bugs Bunny shows in this clip how the exxagerated style of squash and strech and anticipation can really bring the wackyness to life.
When he is pulling the cannon you can really see the walk cycle that Blair drew in the book come to life in the character of bugs bunny. The horse that catches the cannon ball is a great example of exxagerated anticipation as we see the horse rise to an extreme up postion and as the cannon ball comes into contact with him he goes straight down with the weight as it should be however in this style of exxagerated animation the horse almost does a flip on the way down with its hind legs stretched in the air and then returns to the normal position. Also looking at the way that the horses gallop you can see in comparism the difference between this video and the Muybridge horse video. This is an example of how the artistic style creates the feel of the animation.
On the other hand if we reference into the more literal way of doing a walk cycle such as studying the stills that Muybridge provides you end up with a more realistic 'normal' walk cycle.
This shows a woman walking in a very 'normal' realistic and natural way. In the Animators survival kit there is reference to creating the walk cycle using certain poses which work as the keyframes.
There is the contact position in which both feet are in contact with the ground and the arms are generally slightly infront and behind. The next keyframe would be the down position in which the front foot would go fully down and the rear leg would begin to lift with the arms now generally extending to extreme position as the body needs to maintain balance. The next keyframe would be the passing position in which the back leg passes the front one and both arms pass the body. The next keyframe would be the up position which is generally the heighest point in the walk cycle in which the front leg which has now become the back leg lifts up to tip toe and the back leg, now the front begins to extend out ready to go into the contact position once more. A quick attempt at this on ToonBoom studios really helped me visualize it although this is not a very good attempt and there are parts that look very stupid but here it is nonetheless.
I've just noticed about this walk cycle that while the legs seem to be fine, I have seriously messed up the arms which I think has been caused by simple carelessness and the fact that I did not really spend alot of time on this walk cycle. I think if I had spent more time I would've used colours to distinguish the left from right. I also would've tried and given it a slightly more natural and kinetic feel especially in the arms.