Animation creates the illusion of motion by showing a sequence of still images quickly enough that the brain connects them into continuous action. Each drawing or digital pose is a frame, and small changes from one frame to the next make objects appear to move. This matters in art because timing, spacing, and shape changes can make the same bouncing ball feel heavy, light, playful, or realistic.
Good animation is not just many pictures, but carefully planned visual change over time.
A filmstrip or timeline helps animators control motion by organizing frames in order. Wide spacing between positions makes motion look fast, while close spacing makes motion look slow. Techniques such as squash and stretch, arcs, anticipation, and follow-through help drawings feel alive while still obeying believable movement.
When a bouncing ball is animated well, the viewer can read gravity, impact, energy loss, and character from a simple sequence of drawings.
Key Facts
- Animation is created by displaying still frames in rapid sequence.
- Frame rate measures how many images are shown each second, such as 24 fps.
- Time per frame = 1 / frame rate, so at 24 fps each frame lasts about 0.0417 s.
- Speed in animation depends on spacing: speed = distance between positions / time between frames.
- Squash and stretch changes shape to show force and flexibility while keeping volume nearly consistent.
- Arcs make motion feel natural because many real objects move along curved paths under gravity or joint rotation.
Vocabulary
- Frame
- A frame is one still image in an animation sequence.
- Frame rate
- Frame rate is the number of frames shown each second, usually measured in frames per second.
- Timing
- Timing is the control of how long an action takes in an animation.
- Spacing
- Spacing is the distance an object moves between one frame and the next.
- Squash and stretch
- Squash and stretch is an animation principle that changes an object's shape to show impact, speed, or flexibility.
Common Mistakes to Avoid
- Drawing equal spacing for every part of a bounce, because real and believable motion usually speeds up while falling and slows near the top.
- Changing the ball's size during squash and stretch, because the shape may deform but the apparent volume should stay nearly the same.
- Ignoring the arc of motion, because a bouncing object usually follows a curved path rather than jumping between random straight-line positions.
- Adding more frames without planning timing, because smoothness alone does not create convincing weight, force, or personality.
Practice Questions
- 1 An animation runs at 24 fps and a bouncing ball is shown for 48 frames. How many seconds does the bounce last?
- 2 A ball moves 12 cm across the screen in 6 frames at 30 fps. What is its average screen speed in cm/s?
- 3 Two bouncing ball animations use the same number of frames. In one version, the drawings are close together near the top and far apart during the fall. In the other, all drawings are evenly spaced. Which version will look more believable, and why?