Abstract
We interact with rotating panels like doors in our day-to-day life. Doors afford the action of entry and exit from an enclosed space. Since a rotating door can pose a risk of collision to a person standing within the swept volume of the door, the ability to judge a safe distance from the door is imperative. The current study investigated the optical information available to judge whether a rotating panel would collide with or bypass a stationary object nearby. On a desktop computer, participants saw the top-down view of a door-like panel, which rotated about one of three different axes of rotation. A stationary object was placed at a certain distance, within or outside the swept volume of the panel. On top-down view, the axis of rotation of the panel could be at the bottom edge of the panel, at the midpoint between the bottom edge and the middle of the panel, or at the middle of the panel. This means that the proportion of the panel that swung towards the stationary object in each case was 1, 0.75 and 0.5 respectively. Analysis by Cabe (2019) shows that, as a panel rotates towards a nearby object, there is a definite pattern of change in the angle subtended on the object, by the edge of the panel moving towards the object. Such invariant patterns of information may be directly perceivable, which enables the observer to become aware of what the door affords them This study empirically tested whether participants utilize this optical information to judge an imminent collision or bypass. Results suggest that the pattern of change in angle helps observers in judging the event accurately. More importantly, the results also indicate that proper feedback can help in improving such affordance judgments.