DOF-Separation for 3D Manipulation in XR: Understanding Finger-Wrist Separation to Simultaneously Translate and Rotate Objects

Hand-tracking based 3D object manipulation in Extended Reality (XR) typically employs a pinch gesture for acquisition and manipulation through a direct mapping from 6-degrees-of-freedom (DOF) hand movement to that of the object. In this work, we investigate the effect of separating this mapping to concurrent 3DOF controls (DOF-Separation) of translation and rotation of the virtual object using the position and orientation of the hand independently. We aim to understand how DOF-Separation could ease manipulation for different techniques with varying requirements for hand position and orientation during acquisition, including Virtual Hand, Hand Ray, and Gaze&Pinch. Through a user study that features a docking task in VR, we found that DOF-Separation significantly improves the manipulation performance of Hand Ray, while improving that of Virtual Hand only in difficult tasks of combined translation and rotation. We suggest future XR systems to adopt DOF-Separation for input in manipulation-heavy applications, such as 3D design.