The creation of a walk cycle may seem relatively simple but is deceptively tricky. We have many of the same issues that we faced with the bouncing ball here too, but now we have to contend with limbs, a head and a neck, and how they work together as a single unit is of huge importance. Moreover, I suppose because we are used to seeing people walk every day of our lives, a clunky walk cycle sticks out like a sore thumb.
So in order to get it right, as ever, the first step is to gather good reference. Watch people walk: watch kids toddle, the elderly hobble, watch skinny legs stride, watch stout legs waddle. Walk around the house yourself. Work out how many frames are needed to take a step. Get a feeling for what part of the body is leading and which are following (eg the arms will follow the movement of the torso). Gauge how and when weight is transferred from one leg to another. Look for the subtle details such as the slight bob of the head, as these small points add such a lot of depth to the finished piece.
Before beginning the animation, make sure to check your animation preferences. Again, I will be working in PAL (25fps) and as we will be working Pose to Pose, I will also set my Default out tangents to Stepped. You will find this setting under the Tangents tab in the Animation category. This will hold each pose until we hit the next key without any interpolation between. Finally, make sure the arms are in FK mode and the legs are in IK mode. A final point of admin: for this walk cycle, every step will take 12 frames, making the full loop 24 frames.
Once your character is in the starting pose you can create an animation that replicates a full movement that includes the limbs swinging/kicking to the opposite position and then returning to this initial pose. By doing a full cycle we insure that they are now ready to do the same animation again and the positions at the start of the animation will line up.
When you have completed your walk your character will find itself in a very unnatural position. Running the start walk animation would only continue to push the character into a weirder stance. You need to animate the character back to a standing position. To achieve this you can do the opposite animation of the Walk Start and your character will be back where they started at the very beginning.
A Natural Walking MotionOne way animators study for their work is to videotape themselves or others and break down what they see. If you want to create an animation that matches your walking style have a friend videotape you and try to break down what joints are moving when.
At the core of the walking motion are the movement of the legs and the swinging of the arms. The arms swing to counter to the leg motion. This means your right arm swings in sync with the opposite or left leg.
But as adult animators, walking suddenly becomes complicated again. In this lecture, we will learn how to make our animations adhere to the laws of physics, and to accomplish this goal, we will give ourselves the task of animating a character's full walk cycle.
This concept cannot be stressed enough. It is the most common error that shows up in student animations of characters trying to walk. So to hammer this home, stand up and try it. Stand with your feet shoulder width apart with your hips evenly between them. Now try to lift one of your feet off the ground without shifting your hips over the other foot. Can't do it? Neither can Edgar or any other character you animate.
With all this talk about the importance of staying in balance, this next sentence may come as a surprise. But a lot of motion happens because objects are, at least temporarily, out of balance. This is best illustrated by a walk.
A walk is little more than a controlled perpetual fall forward. The character intentionally throws itself out of balance and begins to fall forward. The other leg quickly snaps forward to catch the character before it hits the ground. Then the whole process repeats.
In principle, that is all a walk cycle is. But in practice, animating a walk cycle is a lot more complicated. Walk cycles are hard, even for the most seasoned of animators. It is a constant tug-of-war with the different forces and masses of the body as it continually tries to throw itself out of balance just enough to propel itself forward.
Walk cycles, like all character animation cycles, are made up of poses. When we go to create our first walk cycle, that's where we start. In this section we will break down the crucial poses that make up every walk cycle and the forces that are happening in those poses.
As you can see from the illustration above, the order of the poses as they occur in the walk are: 1) contact, 2) down, 3) passing, 4) up, and 5) contact (which all repeat again mirrored on the other side of the body). That is the order they occur in the walk, but that is not necessarily the order we are going to create them. We are going to work in a pose to pose fashion, which means we can create the poses in any order we would like.
As you can see, what we are doing is repeatedly cutting sections of the time line in half in order to correct the automatic tweening Maya will give us and to help us create a believable transition between the poses. By starting with poses that are far away from each other on the timeline and breaking our walk cycle down into smaller and smaller chunks, we can insure that we are laying out the road map for the animation and subdividing each part of the process.
The first and last pose of a walk cycle is called the contact pose. It is the pose where the heel of the front foot is just slightly touching or "contacting" the ground. The rear foot and leg are pushing the body forward. The character's mass is traveling forward and downward, toward the ground.
Technically, there are two contact poses: the first is the first frame and pose of the animation, and the second contact pose is in the middle of the animation when the foot contacts the ground for the second step. The contact pose at the end is actually just a repeat of frame one, so that the animation loops. This is just to see where the character pose needs to end, more of a place holder. For the animation to cycle, this last frame will be dropped, so it doesn't repeat when the animation loops.
It is important to recognize that all of these poses are just for one footstep of the walk, and it will take two steps to make a full looping walk cycle. So each of the poses we discuss will be repeated again with the side of the body flipped. The walk cycle will end with a duplicate pose of the first contact pose, causing the animation to loop.
Now that we're cozy with the Melvin rig, it's time to get him strolling. The first poses we'll work on with Melvin are his two contact poses. Follow along in the video below as we get Melvin ready to walk.
From the front view you will see that the character's mass is completely over the supporting leg. The grounded leg is nearly straight, pushing the character's hips upward. This is not the highest point of the character's walk cycle, but it is important to note that the leg is driving the character's mass upward.
By the time the character reaches the up pose, it has tipped its weight over the supporting front leg and is beginning to fall forward. The up pose is the highest pose of the entire walk cycle. A slight tip toe on the rear foot (formerly the front foot) will help elevate the hips and head to the highest position.
When we give Melvin his up pose, we'll have a complete walk cycle. Granted, it will still need a lot of polishing, which we'll look at in the next section, but for now the important thing to remember is that the up pose is the final piece of the puzzle. The up pose will occur on frame nine, between the passing pose on frame six and the mirrored contact pose on frame 12. A mirrored up pose will occur on frame 21. Follow along in the video below to complete Melvin's walk cycle:
How does it feel to have a fully walking Melvin on your hands? Are you a little worried he might walk away from you? Don't worry. We'll keep him around to polish him up. First, make sure to review the key points from the video:
The next few videos in this lecture will walk you though the process of polishing the walk cycle and making the animation great. But there are several aspects that many animators overlook while polishing their walk cycle that warrant more discussion.
The arc of the foot is of particular concern because the foot takes a very specific path in a walk animation. Although it is easy to assume the foot makes an arc similar to the bouncing ball, a foot's arc is actually more complex, looking similar to the image below.
Offsetting the keys on different parts of the body will help this problem. This is similar to the way we offset parts of the tail on the previous lecture's animation. Body parts that are higher in the hierarchy will move first, leading the motion. The body parts that are lower in the hierarchy will drag behind, starting a frame or so later. This is evident in the arms, spine, and head. So focusing on those areas will help loosen the walk cycle and make the motion feel more fluid.
Now that you have a standard walk, often called a vanilla walk, you can use this as a base to add character and emotion to the walk. The beauty of the vanilla walk is that all the physicality is built into it; all of the motion is complete. The only thing missing is emotion.
Imagine you wanted to alter the walk to show that the character is looking up at the sky. They easiest way to do this is to simply shift the X rotation curve in the Graph Editor. All the keyframes are already on the curve, we just want each of them rotated higher. So we shift the curve. One easy step can change the entire animation.
Similarly, when adding emotion to a vanilla walk, we need think in terms of pose. To make the character look at the sky, all we'd do is change the general pose of the entire animation, which is much easier than altering each keyframe individually. We alter the overall pose to look upward rather than straight forward. 2b1af7f3a8