Animator: an object-oriented approach

Object-oriented programming is presented as a paradigm for developing interactive systems for computer animation. Object types, evolved conceptually from graphics turtles, are implemented to provide the animator with familiar metaphors for the specification of motion in three-dimensional space. The intention is to create objects that can represent actors, cameras, and decor that the user can direct and animate in a relatively intuitive manner. Vector and turtle objects support the actors, which respond to messages to orient, accelerate and draw themselves on the screen. The MacApp object libraries are used to implement the standard Macintosh user interface and a unit is developed which implements vectors, actors and three-dimensional graphics turtles as obects. The object-oriented approach encourages a conceptual consistency in the external and internal interfaces and is intended to facilitate the development of extensible characters and tools through the cooperative efforts of animators and programmers