Tools, Mediators, and Interaction Operators


We present a flexible and powerful concept for the modeling of interaction in virtual environments. Our approach is based on three basic entities: tools, mediators, and interaction operators.
Tools define the basic interaction mode and are the interface to the user. Mediators are the interface to the scene graph and are attached to nodes in the scene graph. Interaction operators implement the actual interaction functionality and use a tool and a mediator as parameters.
We realized this interaction concept in Avocado, our framework for developing virtual environment applications. We implemented a variety of tools, mediators, and interaction operators for different application prototypes and found our concept to be quite convenient to use.