Simulating Cartoon Style Animation
Stephen Chenney
Mark Pingel
Rob Iverson
Marcin Szymanski
University of Wisconsin at Madison ∗
Abstract
Traditional hand animation is in many cases superior to simu-
lated motion for conveying information about character and events.
Much of this superiority comes from an animator’s ability to ab-
stract motion and play to human perceptual effects. However, expe-
rienced animators are difficult to come by and the resulting motion
is typically not interactive. On the other hand, procedural models
for generating motion, such as physical simulation, can create mo-
tion on the fly but are poor at stylizing movement. We start to bridge
this gap with a technique that creates cartoon style deformations au-
tomatically while preserving desirable qualities of the object’s ap-
pearance and motion. Our method is focused on squash-and-stretch
deformations based on the velocity and collision parameters of the
object, making it suitable for procedural animation systems. The
user has direct control of the object’s motion through a set of sim-
ple parameters that drive specific features of the motion, such as
the degree of squash and stretch. We demonstrate our approach
with examples from our prototype system.
Keywords: deformation, squash-and-stretch, physical simulation,
stylized animation, stylized rendering
1
Introduction
Animators are expert at conveying information through moving im-
agery, be it the personality of a character, their actions, or the ele-
ments of a story. Procedural animation methods, such as physically-
based simulation, also attempt to convey information, yet are typ-
ically less effective than hand animation. Users have traditionally
faced a choice between the high-quality, high-cost of hand anima-
tion and the lower-quality, interactivity of simulated motion.
The superiority of hand animation for communication is not due
to deficiencies in the procedural models, rather to two key anima-
tion skills:
Abstraction Animators extract the essence of a situation and di-
rect a