Visualizing the motion of the pectoral fins is important for enhancing the authentic quality of the artificial fish model. A pair of motionless pectoral fins can make an otherwise life-like swimming fish look awkward. From the simplified functional modeling of the pectoral fins described in Section , a straightforward visualization will be to make the geometric model of the pectoral fins be at an angle corresponding to the 's. Since will only change when necessary and successive angles are generally not continuous, the fin motion will unfortunately look sudden, stiff and hence unrealistic. If we interpolate the angles to yield smooth motion, the fins will look almost motionless compared to the fish's lively body movement. For this reason, we separate the control for visualization purpose from the control for fish locomotion (or functional purpose) described in Chapter .
Real fish can move their pectoral fins in extremely subtle and complex ways that may not be possible to capture accurately using our simplified model. However, many of these delicate details of the fin motions are barely detectable from any distance. In fact, the pectoral fins often move so quickly that only a rough motion pattern, such as flapping or oaring, is distinguishable. We have simulated these two main motion patterns of pectoral movement in the artificial fishes. The implementation details can be found in Appendix and the results are depicted in Fig. and Fig. below.
Figure: Snapshots of the pectoral flapping motion.
|Xiaoyuan Tu||January 1996|