Yu 3D Animation

Part I: Ball Tailed

It’s time to make a little ball motion with a tail!

In order to better understand the trajectory of the ball with a tail, I first looked up a reference picture on the Internet. From the reference picture, you can see the change of the ball’s tail in the process of rising and falling.

I found that the tail’s movement is very typical of an S-curve, which is a soft and flexible object with one main driving force at one point. By relying on their own or external momentum, the force transitions from one end to the other. Squirrels, for example, are characterized by movements that are made of spherical and circular shapes. As the squirrel jumps or runs, its tail will curve accordingly.

I chose to divide the animation of creating the sphere’s motion with the tail into two parts. The motion of the sphere is created first, and then the motion of the tail is created. In this way, I can think about the individual objects’ motion and adjust the overall motion curve during the process.

Here’s a draft drawing of my design for the tailed ball movement.

Model diagram of the scene produced:

Making an animation curve of the sphere’s motion. I started creating keyframes of the sphere’s motion by looking at the ball as a single individual. This way, the subsequent production can adjust the direction of the tail’s movement in reference to the ball’s motion.

Video of ball’s basic motion production:

Now let’s make a tail movement pattern. I chose to create the tail motion keyframes first to see the effect of the tail motion more visually.

Tail’s animation curves panel:

Video of the making tail keyframes:

After making the keyframes, I noticed that the tail was still a bit stiff and not soft. So based on the keyframes, I adjusted the controls for the tail separately. Starting with the controller closest to the tail’s root, I adjusted the two keyframes backward in order. For example, the first controller adjusts two keyframes backward, and the second controller adjusts four keyframes backward.

After adjusting the keyframes:

There are two things I’ve found that it is important to keep in mind during the making process.

1. The arc size before and after the parabola will change.

2. Acceleration and deceleration in motion.

Rending video:

Part II: Ball Walker

I collect reference pictures before making keyframes. In these pictures, I can see the changes in the ball’s movements as it walks.

I divided it into two parts to create keyframes. In this case, I started with the ball legs’ walking motion, then adjusted the details of the ball’s movement and stretching. The ball’s legs are very similar to humans, so I also try to create curves based on the human walking posture.

Reference image about human walking motion:

In the process of walking, the left and right feet alternate forward, driving the torso to move forward. In order to maintain the balance of the body, in line with the two legs to bend and stretch, stride, the upper limbs of the arms need to swing back and forth. In order to maintain the center of gravity when walking, one leg always supports the other leg to lift the stride. Therefore, in the process of walking, the height of the head is bound to move in waves.

Let’s make ball walking! There is a formula to calculate the distance the ball will travel. Distance moved from the waist = distance from the front foot + distance from the back foot + distance from the waist.

Using formulas in the process of making the animation will make the ball move more naturally. Since the ball walking is a circular motion, I made “0” “6” “18” “24” first. Then start making intermediate frames.

Keyframe curves for the lower half of the ball action:

Ball’s basic walk keyframe curves:

This is the motion curve of the ball’s head:

I achieved the goal of moving the model by moving the ball controller and the foot controller during the build process, keeping the total controller free of displacement changes throughout the fabrication process.

This is the movement curves of the final overall model:

Playblast video:

However! A problem has arisen!

I noticed that the ball’s walk looks very terrible. After seeing the playblast video repeatedly, I noticed that the ball’s walk looked skating. Also, the ball’s head movement’s magnitude was unnatural. I could see the ball’s head swinging too low or too high as it moved.

In reviewing the process of making the keyframes, I found the problem. When I was making the foot motion, I rotated the circle controller for the ball’s ankles, which causes the entire foot to rotate with the heel as the center point. This causes the foot’s keyframes to be inconsistent, and the foot will slide forward.

Is there any remedy for this? (Of course, I know that redoing it is a good idea. But please let me try to see if I can remedy it.)

I tried moving the foot back to where it should be at each keyframe. It isn’t pleasant processing but looks better than before.

Ball’s modified controller curve:

Plus board that moves up and down at the feet of the ball.

Look again. Well, much better.

Rending video:

Part one：12 Principles of Animation

Before the production of 3D animation, 12 principles of animation should be fully acquainted. The 12 principles of animation were first introduced by Disney animators Ollie Johnston and Frank Thomas in their work of The Illusion Of Life: Disney Animation. 

In this book, Johnston and Thomas study the work of Disney animators. After the 1930s, their method was reduced to 12 basic principles of animation. These principles form the basis of all animation works.

12 basic principles of animationconsist of:

1. Squash and Stretch
2. Anticipation
3. Staging
4. Straight Ahead Action and Pose to Pose
5. Follow Through and Overlapping Action
6. Slow-in and Slow-out
7. Arcs
8. Secondary Action
9. Timing
10. Exaggeration
11. Solid Drawing and Solid Posing
12. Appeal

I found a picture of the 12 cardinal principles, which I thought would be more interesting to read and help me remind myself to abide by them.

I collected videos about 12 principles of animation and we can see the process of animation production more clearly in the video. Animation comes from life, and respecting the basic laws of physics is the most important. In this way, the logic of action design can be rationalized.

Part two: Bouncing Ball

Before making, I found a sample picture of square and stretch, and we can clearly observe the deformation and trajectory of the ball in the process of free falling in this picture.

In the process of making the bouncing ball animation, I choose two kinds of balls of different quality for squash and stretch motion.

Production process:

In the falling process of the ball, the ball will produce a flattening deformation phenomenon due to the influence of gravity.

In the rising process of the ball, the ball will become an upward elliptical shape due to the influence of gravity.

Graph Editor:

The translate Y axis of a small ball (elastic)

In the first edition of the production of small ball bouncing, the height difference of small ball is too large, resulting in the whole movement looks unnatural. After adjusting the curve panel, I found that the highest point of the ball bouncing keeps a gentle and continuous decline state, which will make the whole movement more natural.

Translate Y axis of big ball (lighter weight)

In order to make the movement of the two balls more in line with the movement rules, I have made adjustments and modifications in the graph editor of each ball. Smooth for both sides of the node of the curve. The object will lose some energy in the process of motion for conservation of energy, so the height of each ball falling will be lower than that of the previous frame.

I think there are two points to pay attention to in the production process:

• Compression and elongation are suitable for elastic objects. They should not be overused, otherwise they will lose the elasticity and become powerless.

• In the process of compression and elongation, the shape of the object changes, while the volume and direction of movement can not be changed.

Bouncing ball animation:

Part 3: Maze of Bouncing Ball

Firstly, the process of maze and bouncing ball is designed. The picture below is the draft.

I hope that the three plates hit by the ball in the process of falling can change their positions after being hit by the ball. Between the two plates on the right side of the design, the bouncing ball will constantly impact, and the speed of the bouncing ball will be faster than that of the plate in the air.

Scene model making：

Making the key frame of bouncing ball movement:

Animation Graph Editor

Stretch the shape of the ball as the ball moves. The shape of the ball in the collision and moving is more in line with the law of motion.

The ball will stretch in the process of acceleration

The ball will be extrusion when it collides

Playbast:

I also tried to render the project for the previous production is realistic style rendering, while this model is not complex for fast rendering. I want to use the cartoon rendering style, so the material of maze model is standard surface.

The material of the bouncing ball is a surface shader. I hope the ball emits light directly so that I can observe its trajectory. I also used a gradient skydome light material.

Renderings:

I reall love this picture style.

Final rendering video:

I really enjoyed the process of making 3D animation. During the learning process, I explored animated keyframing and rendering. This style of the rendering I haven’t tried before. I will try to explore more MAYA production techniques in the future.