Game Development Reference
In-Depth Information
likely to be tall with long legs, and in the second case, it is probably a small creature
with short legs and a fussy temper.
Now let's start the animation workflow. The character's illustration has been imported
in Adobe Flash and has been separated into layers; everything is ready for work.
Traditional animators used frame-by-frame methods to animate characters, drawing
each new frame from scratch. But we can use the advantages of automatic interpol-
ation provided by
Motion Tween
. You need to create only key frames that store the
important phases of motion. All transitional frames are generated automatically. The
following figure shows the basic phases of the protagonist's walking cycle:
The walking cycle consists of two equal parts—step sequences for each leg—so at
least there should be three positions for key frames on the timeline. Let's call them
the
main phases
. The first main phase includes a posture: when the character's
right leg is in front, the right foot is in contact with the surface. This is the beginning
of a step sequence for the left leg, which starts to move forward. The second main
phase is opposite to the first one: the left leg is now in front and has contact. The
third main phase is identical to the first one (it is created by duplicating key frames)
and is needed to create a proper arc for interpolation between the second and first
main phases. To make an important remark, the last frame should be rejected after
the export procedure because it is identical to the first frame of the sequence; if this
is not the case, the sprite sheet will have an unnecessary frozen section and the
walking cycle will not be smooth. In other words, if you have 11 frames in the se-
quence, the first main phase is placed on the frames 1 and 11, the second phase
is on frame 6, and after export, only ten frames will be used because frame 11 is
only technical and is unnecessary. To throw such a frame automatically, you can use
the graphic symbol for your animation. Place it on the main scene, but reduce the
length of the main timeline by one (the graphic symbol will have 11 frames, but the
main scene's timeline will show only 10). Primarily, you need to create the first main
phase, arranging parts of the character in the correct pose. The following basic prin-
ciples can help you with this captious job:
