VR-Grasp: A Human Grasp Taxonomy for Virtual Reality

This paper presents a comprehensive Virtual Reality (VR) grasping taxonomy,
which represents the common grasping patterns employed by users in VR, and is
directly comparable to real object grasping taxonomies. With grasping being one
of the primary interfaces we have with the physical world, seminal work has sought
to explore our explicit grasping actions with real objects with the aim to define
structured reasoning in the form of taxonomies. However, limited work has replicated
this approach, for immersive technology (i.e., VR) and to address this, we present
the first complete taxonomy of grasping interaction for VR, which builds on the
body of work from real object grasping alongside recent approaches which have
been applied into VR. We present a formal elicitation study, wherein a Wizard of
Oz (WoZ) methodology is applied with users (N = 50) tasked to grasp and translate
virtual twins of real objects. We present results from the analysis of 4800 grasps
into a formal structured taxonomy which details the frequency of all potential real
grasps and draws comparisons to the body of prior work in both real grasping and
VR grasping studies. Results highlight the reduced number of grasp types used in VR
(27), and the differences in commonality, frequency, and grasping approach between
real grasping and VR grasping taxonomies. Focus is especially given to the nuances
of the grasp, and via an in-depth evaluation of object properties, namely shape and
size, we illustrate the common trends in VR grasping. Results from this work are
also combined with VR grasping findings from prior published work, leading to the
presentation of the most common grasps (5) for VR and recommendations for future
analysis and use in intuitive and natural VR systems.