Evaluating Foveated Frame Rate Reduction in Virtual Reality for Head-Mounted Displays

TL;DR

This study explores how reducing frame rate in the peripheral vision of VR headsets affects user perception, showing significant rendering cost savings with minimal perceived artifacts.

Contribution

It is the first comprehensive user study on foveated temporal resolution reduction in VR, demonstrating perceptual thresholds for frame rate artifacts.

Findings

Significant reduction in rendering costs achievable

Participants did not perceive artifacts at high levels of frame rate reduction

Perceptual thresholds depend on gaze eccentricity

Abstract

Foveated rendering methods usually reduce spatial resolution in the periphery of the users' view. However, using foveated rendering to reduce temporal resolution, i.e., rendering frame rate, seems less explored. In this work, we present the results of a user study investigating the perceptual effects of foveated temporal resolution reduction, where only the temporal resolution (frame rate) is reduced in the periphery without affecting spatial quality (pixel density). In particular, we investigated the perception of temporal resolution artifacts caused by reducing the frame rate dependent on the eccentricity of the user's gaze. Our user study with 15 participants was conducted in a virtual reality setting using a head-mounted display. Our results indicate that it was possible to reduce average rendering costs, i.e., the number of rendered pixels, to a large degree before participants consistently reported perceiving temporal artifacts.