A Comparative Study on Methods to Interact with Close-Distance Objects in Mixed Reality Environment: Direct Method vs. Raycasting Method

Mixed Reality (MR) technology allows users to interact with virtual objects generated in the real world intuitively. The raycasting method, which uses hand gestures, is a useful way to interact with virtual objects located at a distance in a controller-free environment. However, considering a real-world situation where various obstacles may block the user’s view, it is necessary to study how to interact with close objects. This study aimed to compare the usability of the direct and raycasting methods for interacting with close virtual objects. In the experiment, participants were instructed to manipulate the buttons that were randomly generated at nine specified locations (3 by 3 array) with a distance of 0.5 meters. They were asked to perform the task using both methods and then evaluate the usability and preference of each method. Additionally, task completion time and error frequency were measured to quantitatively compare task performances of them. The results showed that the participants preferred the raycasting method, even though the errors occurred more frequently. It was also found that there was a difference between the two methods in the variation of task performance and preference by button location. This result may be due to the fact that there are some differences between the two methods in terms of interaction characteristics and required body movements. The results of this study are expected to contribute to design more user-friendly user interfaces in MR environments.