Realtime CG Animation of Realistic Fishes using NURBS, Inverse Kinematics and a Co-operative Motion Model

Abstract

In this paper, we present a realistic CG (Computer Graphics) animation method to move fishes. These have highly realistic appearance and movement. NURBS (Non-Uniform Rational B-Spline) is employed for both modeling and deformation of CG fishes. This makes the surface data of the fishes very simple to obtain. We can create the very smooth shape of the fishes (one side) by using about 8 x 4 control points of NURBS. Realistic deformation of the fish is also achieved by forming the control points into several groups and moving them. Inverse kinematics are also incorporated into this deformation. The fishes can swim naturally using a combination of 3 deformation patterns and 3 locomotion patterns. Autonomy of the fishes is realized by a mental model employing random numbers. Both schooling behaviors and collision avoidances are obtained by an algorithm employing detection vector and direction vector. Since the computing costs for this method are not high, we can run the program using general-purpose graphics workstations in realtime.