Pano: Design and Evaluation of a 360° Through-the-Lens Technique

International audience; Virtual Reality experiments have enabled immersed users to perform virtual tasks in a Virtual Environment (VE). Before beginning a task, however, users must locate and select the different objects they will need in the VE. This first step is important and affects global performance in the virtual task. If a user takes too long to locate and select an object, the duration of the task is increased. Moreover, both the comfort and global efficiency of users deteriorate as search and selection time increase. We have developed Pano, a technique which reduces this time by increasing the users natural field of view. More precisely, we provide a 360 panoramic virtual image which is displayed on a specific window, called the PanoWindow. Thanks to the PanoWindow, users can perceive and interact with the part of the Virtual Environment (VE) that is behind them without any additional head or body movement. In this paper, we present two user studies with 30 and 21 participants in different VEs. For the first study, participants were invited to perform object-finding tasks with and without Pano. The second study involved position-estimating tasks in order to know if the PanoWindow image enables users to build an accurate representation of the environment. First, the results show that Pano both reduces task duration and improves user comfort. Second, they demonstrate that good object-localization accuracy can be achieved using Pano.