Lesson Plan
Course Title:
Animation
Session Title: Creating the Bouncing Ball: Arcs, Easing,
and Squash and Stretch
Lesson Duration: Two 90-minute class periods
[Lesson length is subjective and will vary from instructor to instructor]
Performance Objective:
Upon completion of this assignment, the student will complete an animation of a bouncing ball
that includes motion in arcs, easing, and squash and stretch.
Specific Objectives:
1. State the rationale of the bouncing ball animation.
2. Identify three principles of animation covered in the bouncing ball animation.
3. Discuss the principles of animation involved in creating a bouncing ball animation.
Preparation
TEKS Correlations:
130.83(C)
(2) The student understands professional communications strategies. The student is expected
to:
(A) adapt language for audience, purpose, situation, and intent; and
(E) apply active listening skills.
(10) The student develops an understanding of animation. The student is expected to:
(A) demonstrate appropriate use of hardware components;
(B) demonstrate appropriate use of software programs;
(C) demonstrate appropriate use of storage devices;
(I) publish and deliver the product in a variety of media;
(L) evaluate a product using critical thinking skills; and
(N) create animation projects using a variety of techniques and software programs.
Instructor/Trainer
References:
1. Webster, Chris (August, 2005). Animation: The Mechanics of Motion. Focal Press. ISBN:
0240516660
Instructional Aids:
1. Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch slide presentation
2. Bouncing Ball Schematics (drawing of correct placement and shape of individual frames)
3. Creating a Bouncing Ball Animation Rubric
(Note: Teachers may need to adapt rubric terminology and elements to fit the course
materials and/or software used)
Materials Needed:
Bouncing ball
AAVTC: Animation: Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch
Copyright © Texas Education Agency, 2012. All rights reserved.
1
Optional: Lightboard, drawing paper, sketch pencils
Search online for a video of a bouncing ball animation
Equipment Needed:
1. Projection system to display the slide presentation and to watch an online video.
2. Computer with some animation software. The students’ animation projects may be
completed using any 3D or 2D application. The projects may also be completed using a
lightboard and paper for traditional hand drawn animation.
Learner
None.
Introduction
MI
Introduction (LSI Quadrant I):
ASK: As a ball bounces along, what does the path look like?
[A bouncing ball moves in an arced path.]
DO:
Use a white board and illustrate the path.
ASK: What happens to the speed of the ball as it bounces?
[The ball speeds up when moving down then slows down on the upward path
due to gravity.]
ASK: What happens to the shape of the ball as it bounces?
[Depending on the type of material the ball is made from, the ball squashes
on impact and stretches before and after impact.]
Outline
MI
Outline (LSI Quadrant II):
I. Rationale of the bouncing ball animation
A. Starting point for all animators
B. If an animator cannot make a ball bounce in a
believable fashion, it would not be wise to try more
complex exercises
C. Animators should have an example of a bouncing
ball somewhere in their portfolio (reel)
Instructor Notes:
Use the software
presentation (Slide 2)
to discuss the rationale.
II. Three principles of animation covered in the bouncing
ball animation
A. Motion in arcs
B. Slow in/slow out (easing)
C. Squash and stretch
Ask students to attempt
to identify the applied
principles in the
bouncing ball animation
before showing Slide 3.
III. Principles of animation involved in creating a bouncing
ball animation
A. Motion in arcs
 Ball falls in an elliptical arc through space
 If the ball moved in a straight line between the
Use the software
presentation (Slides 413) to discuss these
concepts.
AAVTC: Animation: Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch
Copyright © Texas Education Agency, 2012. All rights reserved.
2
top and bottom points of the bounce, the action
would appear unnatural.
B. Slow in/slow out (easing)
 As the ball falls it is accelerated by gravity
 As the ball bounces, it moves very fast at first,
then is slowed by gravity at the high point of its
bounce
 At the high point of the bounce, the ball is
weightless
C. Squash and stretch
 When it impacts the ground, the ball squashes.
The volume must remain the same. If an object
becomes wider (squashed) it must also become
shorter. Squeezing a balloon illustrates the
concept of constant volume while squashing
and stretching.
 At some point as the ball falls, it stretches.
When it impacts the ground, it squashes. When
it bounces off the ground, it stretches again.
Note how quickly the ball regains its circular
shape.
Application
MI
Guided Practice (LSI Quadrant III):
Go over the slide presentation with the class and discuss the principles involved in
creating an animation project. The teacher should go over the techniques required in
the software application that will be used. Students should watch the demonstration
and provide input in response to the teachers’ questions and the class discussion.
MI
Independent Practice (LSI Quadrant III):
Students will use online software or hand drawings to create a four-second bouncing
ball animation that uses the principles of arcs, easing, and squash and stretch.
AAVTC: Animation: Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch
Copyright © Texas Education Agency, 2012. All rights reserved.
3
Summary
MI
Review (LSI Quadrants I and IV):
Once the students finish their animations, they should share their finished projects
with the whole class. Throughout the presentations, students should try to see if any
of the animations are missing one or more of the basic principles for creating a
bouncing ball.
Evaluation
MI
Informal Assessment (LSI Quadrant III):
Teacher monitors individual progress as students work on the project. The teacher
will assist any student that has problems with the software or basic concepts of the
project.
MI
Formal Assessment (LSI Quadrant III, IV):
The teacher will assess the final bouncing ball animation using the rubric.
(Note: Teachers may need to adapt rubric terminology and elements to fit the
course materials and/or software used)
Extension
MI
Extension/Enrichment (LSI Quadrant IV):
Students may use this technique in many creative ways such as:
 Making a ball bounce down a set of stairs.
 Making a ball bounce around a room – bouncing off the floor, walls, and ceiling.
 Making a helium balloon bounce around a room.
 Animating a character dribbling a basketball.
AAVTC: Animation: Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch
Copyright © Texas Education Agency, 2012. All rights reserved.
4
Creating a Bouncing Ball Animation Rubric
Criteria
Modeling
(5 pts)
Squash and
Stretch
(30 pts)
Motion in Arcs
(30 pts)
Easing
(30 pts)
Lighting and
Rendering
(5 pts)
Exceptional
Above Average
Below Average
Poor
5 points
4 points
All objects are
created at the
expected size
and proportion.
There is one
minor modeling
mistake.
27-30 points
24-26 points
3 points
More than one
modeling mistake
but they caused
only minimal
problems to the
animation.
21-23 points
0-2 points
More than one
modeling
mistake that
caused major
problems to the
animation.
0-20 points
The ball is scaled
appropriately so
that squash and
stretch is evident.
There are a
couple of minor
problems with
squash and
stretch.
There are several
problems with
squash and
stretch.
Squash and
stretch was not
applied or
caused major
problems.
27-30 points
24-26 points
21-23 points
0-20 points
The ball always
moves in a
believable arc.
There are a
couple of minor
problems with the
path of the ball.
There are several
problems with the
path of the ball.
There are major
problems with
the path of the
ball.
27-30 points
24-26 points
21-23 points
0-20 points
The ball moves at
an appropriate
speed with no
easing problems.
There are a
couple of minor
problems with
easing.
There are several
problems with
easing.
Easing was not
applied or
caused major
problems.
5 points
4 points
3 points
0-2 points
The animation
used appropriate
lighting and was
rendered as
directed.
There was one
minor problem
with lighting or
rendering.
There were two
or more minor
problems with
lighting or
rendering.
There were
major problems
with lighting or
rendering.
Points
Total_______________
AAVTC: Animation: Creating the Bouncing Ball: Arcs, Easing, and Squash and Stretch
Copyright © Texas Education Agency, 2012. All rights reserved.
5