Effect of a constant camera rotation on the visibility of transsaccadic camera shifts

Abstract

Often in 3D games and virtual reality, changes in fixation occur during locomotion or other simulated head movements. We investigated whether a constant camera rotation in a virtual scene modulates saccadic suppression. The users viewed 3D scenes from the vantage point of a virtual camera which was either stationary or rotated at a constant rate about a vertical axis (camera pan) or horizontal axis (camera tilt). During this motion, observers fixated an object that was suddenly displaced horizontally/vertically in the scene, triggering them to produce a saccade. During the saccade an additional sudden movement was applied to the virtual camera. We estimated discrimination thresholds for these transsaccadic camera shifts using a Bayesian adaptive procedure. With an ongoing camera pan, we found higher thresholds (less noticeability) for additional sudden horizontal camera motion. Likewise, during simulated vertical head movements (i.e. a camera tilt), vertical transsaccadic image displacements were better hidden from the users for both horizontal and vertical saccades. Understanding the effect of continuous movement on the visibility of a sudden transsaccadic change can help optimize the visual performance of gaze-contingent displays and improve user experience.