Trade-Off between Task Accuracy, Task Completion Time and Naturalness for Direct Object Manipulation in Virtual Reality

Jari Kangas,Roope Raisamo,Jorma Järnstedt,Sriram Kishore Kumar,Helena Mehtonen

doi:10.3390/mti6010006

Abstract

Virtual reality devices are used for several application domains, such as medicine, entertainment, marketing and training. A handheld controller is the common interaction method for direct object manipulation in virtual reality environments. Using hands would be a straightforward way to directly manipulate objects in the virtual environment if hand-tracking technology were reliable enough. In recent comparison studies, hand-based systems compared unfavorably against the handheld controllers in task completion times and accuracy. In our controlled study, we compare these two interaction techniques with a new hybrid interaction technique which combines the controller tracking with hand gestures for a rigid object manipulation task. The results demonstrate that the hybrid interaction technique is the most preferred because it is intuitive, easy to use, fast, reliable and it provides haptic feedback resembling the real-world object grab. This suggests that there is a trade-off between naturalness, task accuracy and task completion time when using these direct manipulation interaction techniques, and participants prefer to use interaction techniques that provide a balance between these three factors.

Highlights

Virtual reality (VR) devices, e.g., head-mounted displays (HMDs), are becoming mainstream tools in a wide range of different domains, for example, in entertainment, marketing, education, and training
The results indicate that while there were no significant differences between methods in task performance or workload, the participants preferred the mixed mode
We found statistically significant differences between the interaction techniques, where HandOnly was significantly slower than both other methods (the p-value was in both cases below 0.017 (= 0.05/3), using Bonferroni correction of doing three comparisons, p < 0.005, CI = 5.6 − 12.4, 1 − β = 0.92 for comparison between HandOnly and Controller+Trigger, p < 0.005, CI = 4.7 − 10.9, 1 − β = 0.86

Summary

Introduction

Virtual reality (VR) devices, e.g., head-mounted displays (HMDs), are becoming mainstream tools in a wide range of different domains, for example, in entertainment, marketing, education, and training. They make it easy to cater immersive experiences with the user situated in a realistic three-dimensional (3D) environment where he/she can, for example, observe, learn and act on virtual, dynamic constructions that could not be arranged in reality. Hand tracking [17,18,19,20,21,22] is a prime example of direct manipulation methods (Shneiderman [23]) in which objects are interacted physically and incrementally with immediate feedback.

Methods

Findings

Discussion

Conclusion