This week, our task was to choose one character from resources to create a full body walk cycle. I chose the hottest girl model.
Reference
A walk cycle can be basically divide into 4 sections: contact, low point, passing, high point. Before I got into my work, I saw a tutorial on YouTube, which gives a great demonstration of full body walk cycle.
In addition to basic hand and foot swings, there are the following things to note:
Weight and hip shift
When doing a walk cycle, the body doesn’t stay front all the time. As the feet alternately lift and step down, the body’s weight will shift constantly from left to right or from right to left. When lift one feet (a), the weight of body will shift to the opposite side (b), so I should drag the hip to this side (b) slightly in order to show the other feet (b) supporting the weight of body. Besides, While walking, the hip and waist of the feet that going forward is also facing forward a little bit. Simultaneously, When lift one leg, the hip on the other side is slightly higher, therefore, I should rotate the hip down to the raised leg. Passing is usually the extreme point.
Rotation and swing of lower leg and ankle
When the leg and ankle are going up, they don’t just go in a straight line, they should open and rotate a little bit.
Rotation of torso
The rotation on z axis of torso is always opposite to hip’s so as to offset the imbalance of whole body.
Rotation of shoulder
It is always the shoulder that drives the arm to swing, so when the arm wants to swing forward, the shoulder should move forward in advance. On the contrary, when the arm is about to swing backward, the arm should rotate back in advance.
Process
Followed the principles in reference, I finished keying the first 25 frames. Afterwards, I used a command loop to expand the first 25 frames of action. Firstly, selected all controllers, went to graph editor, selected all curves, clicked on view – infinity, and then clicked on curves – post infinity – cycle with offset. Then the first 25 frames got an infinity loop.
Constraints & parenting
Point
The constrained object’s centre point snaps to the parent’s. However, when you rotate the parent, the constrained object remains unchanged.
Orient
Scale
Aim
Parenting
Parenting physically put the object within the other one in the outliner.
Difference between constraints and parenting
- When using parenting, the first object you click on is child. However, when using constrains, the first one click on is parent.
- After constraining, the child cannot be move away. Ever if it is moved, it will back to the original position as the parent move around. However, if you want to move the child individually, the child should be grouped before constraining. In that case, you can move the constrained object individually. But, do not move the group cause it is the child of parent.
After distinguishing these functions, I wanted to let my character holding a cup in her hand while walking.
I adjusted her fingers to make her holding the cup tightly. And then I selected the body first and secondly the cup to make the cup constrained to the body. Now if I clicked on the play button, she was holding the cup and walking forward.
Outcome
Summary
Through this task, I had a better understanding of whole body walk cycle as well as the rotation and movement of every rig and joint. Furthermore, I learned how to use parenting and constraints. However, the animation outcome seems that the walk pace of character is not smooth enough, it seems that she is stopping and restarting within her every step. The reason causing this happened is the curve of translate z is not smooth enough, there are ripples in the line.