1.0 First Production
Step1: Making plan
First, understand the principle of the falling motion of the bouncing ball. The core of this process revolves around the four stages: falling – collision – rebound – attenuation.
- Fall: When a small ball falls from a height, it is subject to the force of gravity, resulting in an increasing speed and larger distance in the falling stage.
- Collision: This demonstrates the Squash and Stretch in 12 Principles of Animation. The ball will be stretched by the force of gravity when it approaches the ground (as shown in the blue part of the picture), and compressed by the impact when it touches the ground (as shown in the pink part of the picture).
- Bounce: The ball bounces back after colliding with the ground.
- Damping: After each collision, the kinetic energy of the ball decreases due to friction and deformation, causing the rebound height to gradually decrease and the speed in the horizontal direction to gradually slow down.
Note:
The trajectory of the small ball is a smooth parabola. Due to energy loss, the parabola gradually becomes smaller, and the moving distance of the ball in the horizontal direction decreases.
Step2: Animating
- Set keyframes for the movement trajectory of the small ball:
First, adjust the screen to the front view. Then, set keyframes at the highest and lowest points of each movement trajectory of the small ball. Open the curve editor, cut off the keyframe of the lowest point, adjust each parabolic curve, so that the movement trajectory of the small ball is smooth.
- Set keyframes for the rotation of the small ball:
During the bouncing process of the small ball, it will keep rotating. After stopping bouncing, it will continue to roll for a certain distance.
- Set keyframes for the deformation of the small ball:
According to the plan, the small ball will stretch when approaching the ground and squash when colliding with the ground. Each deformation is weaker than the previous one. When it no longer bounces, it will roll without deformation.
Note:
When the small ball collides with the ground, it must not go beyond the ground; otherwise, it will cause a collision through the model.
2.0 Revised
Step1: Planning
As a plan, I need to label the data as precisely as possible. Therefore, during the revision process, I added specific key frame plans, as well as when the ball squash and stretch, and also drew the deceleration movement of the ball at the end of the roll.
Step2: Animating
- Added the ground.
- Due to the poor elasticity of the ball in the real scene, I reduced the deformation degree of the ball.
- When the ball stops bouncing, its rolling speed decreases gradually until it stops.
- Turned off the controller to observe the ball animation.