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Chapter 7
Animation
The animation of the fish is divided into two sections. First there is the animation of the fish
form, which at this stage comprises only the movement of the fins. The second section is the
behaviour of the fish which determines the way in which the fish moves around the environment.
This is achieved by implementing a simple flocking algorithm. Although these two sections are
discussed separately they are not mutually exclusive in the rendering process: as fish move
around the environment they move their fins, producing a realistic swimming motion.
7.1 Fin Motion
A very simple movement model for the fin motion has been implemented. There is no deformation of the body area at this stage, although this is theoretically possible, nor are the fins
deformable. The only movement is due to certain of the fins moving back and forth. The dorsal,
adipose and anal fins do not move at all in relation to the body (See Figure 7.1for a summary).
The caudal fin moves back and forth, up to a certain maximum angle, we will call this maximum angle the movement angle of the fin. The movement angle is specified by the user in the
Side View
Top View
Figure 7.1: Fish structure showing fin movements.
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