Game Development Reference
8 Keyframe animation
Animation is magic. Creating static imagery by any means, drawing,
painting, sculpture or CGI, is interesting and the results can often be
arresting and full of emotion, but they are not magic. Animation is magic.
Seeing the results of your labours come to life, walking, talking or fighting,
as is the case with far too many computer games, generates the buzz of
excitement that is the real reward for the hard work. If you are new to
animation then seeing your character move for the first time will be a huge
kick. If you intend to do some animation of your own and you are starting
from scratch, I recommend using as much reference material as you can.
You will be particularly interested in the section about using live action.
This chapter covers essentially two topics. We look at animation from the
artist's perspective and we look at it from the programmer's viewpoint.
Since this topic is essentially for programmers, you may be surprised at
the coverage of the artists' concerns, but if you intend to write software
that will be used by artists then you need to know their problems before
you can provide the solutions. Otherwise, you provide solutions to non-
existent problems and no solution to their real problems.
Principles of animation
Most people know that animation is made up from a series of static
images that are changed rapidly before the viewer, who, being unable to
detect the change of image, reads the result as a moving sequence.
Animation uses a limitation of our eyes, persistence of vision. Our eyes
are terrific at detecting movement but there is a finite limit to how quickly
we can view a changing scene. In the nineteenth century, lots of toys were
invented that exploit this limitation. It was discovered that if you flash a
series of static images quickly enough then the result appears to our eyes
as a moving scene. These early devices included 'Zoetropes' and
'Praxinoscopes'. A Zoetrope is a short, wide cylinder that has a series of