Trade-offs in Virtual Grasping: The Interplay of Interaction Fidelity and Object Affordance

초록

In Virtual Reality (VR), object grasping is a core interaction that critically influences both user immersion and task performance. While contemporary systems offer both high-precision controllers and intuitive hand tracking, they present a trade-off between performance and naturalness. However, empirical guidance for selecting an optimal grasping method for object grasping remains limited. In particular, how object shape and size (as affordance-related factors) modulate this trade-off within a standardized pick-and-place paradigm is underexplored. We investigate the interplay between interaction fidelity and object shape/size and its impact on user performance and experience in a controlled pick-and-place task. We conducted a within-subjects study with a 3 (grasping modality: controller, pinch, plausible gesture) x 5 (object shape: cube, sphere, cylinder, handled mug, complex model) x 3 (object size) factorial design. We measured objective performance (task completion time, placement accuracy) and subjective experience (NASA-TLX workload, IPQ presence). Our findings provide evidence-based answers to the scoped question: "Which grasping method is best suited for an object of a given shape and size in a pick-and-place task?" Ultimately, this work offers actionable guidelines to help VR developers design effective and satisfying object-grasping interactions tailored to users' task goals and virtual environments, without claiming a single universally "best" method.