Abstract
This thesis describes a method for simulating the flight of birds in a flock with the use of physically-based aerodynamics. The resulting flocking behavior dramatically improves on results previously obtained in computer graphics and animation. Previous attempts at simulating flocks realistically, although believable, do not consider the subtle motions a bird makes when maneuvering to remain in a flock. The motion of the bird's wing is pre-stored as a cubic spline curve. Aerodynamic properties such as the surface area of the wing, the wingspan and the wing velocity are also stored as cubic splines for immediate retrieval during simulation. A flight simulator interface allows the flock's path to be choreographed from the viewpoint of a lead bird. As the bird is maneuvering, subtle changes in the twisting and flapping of the wings, as well as a dynamically maneuverable tail are made to provide the bird with the necessary mechanics to maneuver through the air. A control system (mimicking the bird's internal control strategy) differentially twists the wings, and maneuvers the tail in such a way as to provide the lift and torque necessary to turn the bird in a desired direction. This provides more realism because the subtle changes occur in a way similar to an actual bird. Previous flocking methods do not consider differential twisting of the wings and do not manipulate the tail to assist in a turn. The flocking algorithm is built upon the aerodynamic bird model and control system. This algorithm provides desired direction and speed for each bird, and the control system adjusts the bird's behavior to achieve these goals.
Ringham, Michael Lynn (1996). Physically-based aerodynamic flight of birds: an interactive approach to behavioral flocking. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1996 -THESIS -R56.