Towards Understanding Depth Perception in Foveated Rendering

TL;DR

This study investigates how foveated rendering, which reduces peripheral visual detail, affects stereoscopic depth perception in virtual reality, finding that depth perception remains unaffected even with significant peripheral blur.

Contribution

The paper provides the first quantitative evaluation of peripheral blur's impact on stereoscopic depth perception and proposes a perceptual model for foveation levels that preserve stereoacuity.

Findings

Stereoscopic acuity remains unaffected by high peripheral blur levels.

Foveated rendering does not impair depth perception up to 2x stronger foveation.

The proposed perceptual model guides foveation settings without degrading stereoacuity.

Abstract

The true vision for real-time virtual and augmented reality is reproducing our visual reality in its entirety on immersive displays. To this end, foveated rendering leverages the limitations of spatial acuity in human peripheral vision to allocate computational resources to the fovea while reducing quality in the periphery. Such methods are often derived from studies on the spatial resolution of the human visual system and its ability to perceive blur in the periphery, enabling the potential for high spatial quality in real-time. However, the effects of blur on other visual cues that depend on luminance contrast, such as depth, remain largely unexplored. It is critical to understand this interplay, as accurate depth representation is a fundamental aspect of visual realism. In this paper, we present the first evaluation exploring the effects of foveated rendering on stereoscopic depth perception. We design a psychovisual experiment to quantitatively study the effects of peripheral blur on depth perception. Our analysis demonstrates that stereoscopic acuity remains unaffected (or even improves) by high levels of peripheral blur. Based on our studies, we derive a simple perceptual model that determines the amount of foveation that does not affect stereoacuity. Furthermore, we analyze the model in the context of common foveation practices reported in literature. The findings indicate that foveated rendering does not impact stereoscopic depth perception, and stereoacuity remains unaffected with up to 2x stronger foveation than commonly used. Finally, we conduct a validation experiment and show that our findings hold for complex natural stimuli.