Evaluating Foveated Frame Rate Reduction in Virtual Reality for Head-Mounted Displays (2505.03682v1)

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.

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

The paper "Evaluating Foveated Frame Rate Reduction in Virtual Reality for Head-Mounted Displays" presents a novel approach for improving rendering performance in virtual reality (VR) environments by using foveated temporal resolution reduction. This method selectively reduces the frame update rate in the peripheral regions of the user's field of view without affecting the spatial quality.

Overview

In the context of VR, where computational demand is high, traditional foveated rendering techniques primarily reduce spatial resolution in peripheral vision areas to enhance rendering efficiency. However, the concept of modulating temporal resolution, that is, altering the refresh rate based on eccentricity, remains relatively unexplored. This paper addresses this gap by evaluating how frequency reduction in peripheral vision affects user perception and comfort.

Methodology and Results

The research involved a user paper with 15 participants utilizing VR headsets to explore the perceptual effects of varying frame rates across different gaze-dependent screen regions. This setup employed distinct frame rate configurations, where inner foveal areas maintained a high refresh rate, and outer peripheral zones were set to lower rates. The paper analyzed feedback on perception, distraction, and discomfort related to the temporal artifacts caused by this approach.

Notably, the findings indicate that rendering costs can be reduced significantly—up to 63.6%—without provoking noticeable discomfort in users. Despite perceiving temporal artifacts, users reported low levels of discomfort, suggesting potential for practical application in VR systems where computational constraints are critical.

Implications

The implications of this research are multifaceted. Practically, this technique could enhance the performance of VR systems by significantly reducing the computational load, potentially enabling more immersive and detailed experiences without upgrading hardware. Theoretically, it opens avenues for further exploration of temporal resolution modulation across various contexts, challenging the predominant focus on spatial degradation alone.

Speculations on Future Developments

Looking forward, this paper's insights suggest several promising directions for advancing VR rendering methods. Integrating spatio-temporal re-projection techniques could further refine the balance between perception quality and performance efficiency. Future investigations may include expanded user studies with diverse demographics to more thoroughly understand the potential variability in perception and discomfort. Moreover, exploring adaptive methods that dynamically adjust both spatial and temporal resolution in response to real-time user behavior could further enhance VR experiences.

In conclusion, this paper contributes a compelling perspective on leveraging temporal resolution manipulation in VR, emphasizing the feasibility and efficacy of this technique under specific conditions, while also laying the groundwork for future investigations into its broader applications and optimizations.