Optic Flow Backgrounds: Using Egomotion Perception to Support Navigation in a 3D Computer World

As computer systems become increasingly complicated, it is harder for users to maintain an overview. In many professional applications, user tasks are spread out over many windows located on different virtual screens, and sometimes displayed on a single physical screen. The design of the interface for this must enable the user to understand the relative locations of these windows. Studies of navigation in airplanes and automobiles have established that egomotion is an important contributor to people’s sense of orientation: people can rapidly, accurately, and with little conscious effort tell the direction of movement from visual flow patterns displayed on a screen. It has also been reported that this perception of egomotion can be elicited from computer graphics that simulate the flow of a visual scene moving past an observer. This paper proposes an interface that uses such visual flow patterns to support users navigating between application windows on screens that are virtually placed around the user. Three-dimensional background images on a computer screen are generated to give users a sense of egomotion. One “home” window is located in the direction of egomotion, and serves as a reference point for the application acting as a main menu or a starting/exit point. Users can switch between multiple windows located on both sides of the home window, just like turning their head right or left. When they turn to the direction of their screen, the flow in the background helps them to stay aware of the direction of the home window. The proposed interface was implemented into an e-mail application and validated through an experiment. Eighteen undergraduate students participated as subjects. Performance data showed that the proposed method had a significant advantage in reducing errors. Subjective evaluations also indicated a significant advantage of the proposed interface for a user’s overview of a complex environment.