Rotation Methods for 360° Videos in Virtual Reality - A Comparative Study

Abstract

Advances in VR technology enabled the development and distribution of 360° videos. Also called panoramic videos, this type of media is shot from multiple camera angles, forming a complete surround experience. Paired with a HMD device, this creates a fully immersive experience. For the majority of 360° video players, view point changes in order to explore all viewing directions are often exclusively performed by head movements. While this design helps greatly with immersion, it also creates some practical problems. To explore the content of a video in all viewing directions, a viewer has to rotate their whole body along the yaw axis. This is especially problematic if the viewer wishes to remain stationary, for example on a non-rotating chair. In this case, the whole video content can only be accessed by performing extreme head movements and straining neck rotations. This work focuses on implementing alternative rotation methods which allow a viewer to fully navigate the content of a video while remaining in a stationary position and while avoiding straining head rotations. To this end, three distinct rotation methods have been created, each being a representative for a basic interaction concept. A GUI method, which implements additional graphical user interface elements, a thumbstick method, utilising a physical VR controller as input, and a dragging method, which uses gestures for video rotation. These methods are then analysed and compared against each other in a user study, focusing both on viewer performance as well as subjective feedback. The results show that while there is no complete elimination of head movement, nor significant difference of it between the three rotation methods, every rotation method allows a viewer to navigate the video content from a stationary position. Participant feedback suggests that the Thumbstick method was best suited for this task. These results suggest that implementing the Thumbstick method into 360° video players provides viewers with a powerful alternative for video navigation. The additional inclusion of the Dragging method provides viewers with multiple options for rotation which accommodates different preferences.