Controller-Free Hand Tracking for Grab-and-Place Tasks in Immersive Virtual Reality: Design Elements and Their Empirical Study

Alexander Masurovsky,David Przewozny,Michael Gaebler,Detlef Runde,Paul Chojecki,Mustafa Lafci

doi:10.3390/mti4040091

Abstract

Hand tracking enables controller-free interaction with virtual environments, which can, compared to traditional handheld controllers, make virtual reality (VR) experiences more natural and immersive. As naturalness hinges on both technological and user-based features, fine-tuning the former while assessing the latter can be used to increase usability. For a grab-and-place use case in immersive VR, we compared a prototype of a camera-based hand tracking interface (Leap Motion) with customized design elements to the standard Leap Motion application programming interface (API) and a traditional controller solution (Oculus Touch). Usability was tested in 32 young healthy participants, whose performance was analyzed in terms of accuracy, speed and errors as well as subjective experience. We found higher performance and overall usability as well as overall preference for the handheld controller compared to both controller-free solutions. While most measures did not differ between the two controller-free solutions, the modifications made to the Leap API to form our prototype led to a significant decrease in accidental drops. Our results do not support the assumption of higher naturalness for hand tracking but suggest design elements to improve the robustness of controller-free object interaction in a grab-and-place scenario.

Highlights

Immersive Virtual Reality (VR) enables the user to “dive into” a computer-generated 3D environment
There were significant main effects of interface for all performance measures (Table 1), which were driven by the Oculus controller performing significantly better than the HHI_Leap on all performance metrics (Table 2)
Our study forms a basis for determining the state of the art of a flexible, common implementation of a hand tracking virtual reality (VR) interface by comparing it to a traditional VR controller, on a task representative of the types of motions found in VR applications

Summary

Introduction

Immersive Virtual Reality (VR) enables the user to “dive into” a computer-generated 3D environment. Commercial VR systems (e.g., Oculus Rift, HTC Vive) enable interaction with virtual environments and objects (beyond head movements) typically by way of handheld controllers (e.g., the Oculus Touch). Such setups have been used, for example, for safety and equipment training in mining (e.g., [4]) or manufacturing scenarios (e.g., [5]). VR enables naturalistic (i.e., dynamic, multisensory, interactive) experiments while maintaining full experimental control and allowing precise measurements of the participant’s behavior [6,7,8,9].

Methods

Results

Discussion

Conclusion