Raycasting-based interaction techniques are widely used for object selection in immersive environments. Despite their intuitive use, they come with challenges due to small or far away objects, hand tremor, and tracking inaccuracies. Previous adaptations for raycasting, such as directly snapping the ray to the closest target, extruding the ray to a cone, or multi-step selection techniques, require additional time for users to become familiar with them. To address these issues, we propose three assistive techniques in which the visible selection ray is subtly redirected towards a target, with a proximity and gain based increase in the redirection amount. In a user study (N = 26), we compared these redirection techniques with a baseline condition based on a Fitts’ law task and collected performance measures as well as comprehensive subjective feedback. The results indicate that the three redirection techniques are significantly faster and have higher effective throughput than the baseline condition. Participants retained a high sense of agency with all redirection techniques and reported significantly lower total workload compared to the baseline. The majority of participants preferred selection with assistive ray redirection and perceived it as not distracting or intrusive. Our findings support that assistive redirected raycasting techniques can improve object selection performance and user experience in virtual environments.

Free access to the definitive version of this paper in the ACM Digital Library: https://dl.acm.org/doi/10.1145/3611659.3615716?cid=99659576953

The research for this paper was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC 2176 'Understanding Written Artefacts: Material, Interaction and Transmission in Manuscript Cultures', project no. 390893796. The research was conducted within the scope of the Centre for the Study of Manuscript Cultures (CSMC) at Universität Hamburg.