Perception-based high quality distributed virtual reality

Abstract

Virtual reality has great potential to enable remote collaborative work from anywhere in the world. Developing virtual reality into a platform suitable for natural interaction and immersive collaboration requires the experience to be reliably stable. For a networked collaborative environment, perceived smoothness of motion is limited by the tick rate, that is, the frequency at which information is distributed. As tick rate increases, motion will appear increasingly smooth; however, excessive tick rates may introduce additional load on a network without any perceptible benefit to a user. This paper details two visual psychophysics experiments (N_1 = 16, N_2 = 11) carried out to evaluate participant sensitivity to tick rate in virtual reality. The influence of three variables, velocity, complexity, and digital medium were investigated. Both velocity and digital medium displayed a significant effect, whilst complexity did not show significance. A model was then built and validated from the results of these experiments. The model predicts for average walking speed within the desktop condition, that 90% of the population will perceive motion to be smooth at 56 Hz, whilst this 90% threshold lies at 113 Hz for the VR condition. This model can predict participant perception of tick rate under given conditions, enabling networks to intelligently optimise participant experience without adding unnecessary further load on the network.