Low-Latency Ocular Parallax Rendering and Investigation of Its Effect on Depth Perception in Virtual Reality

Area of Science:

• Human-computer interaction
• Virtual and Augmented Reality
• Visual Perception

Background:

• Virtual/augmented reality (VR/AR) displays increasingly incorporate eye states for immersive experiences.
• Ocular parallax, generated by eye rotation, significantly impacts depth perception but is challenging to assess due to head-mounted display (HMD) latency.
• Accurate assessment of ocular parallax requires high-speed, low-latency systems.

Purpose of the Study:

• To develop a high-speed, low-latency ocular parallax rendering system.
• To investigate the latency requirements for perceptually stable ocular parallax rendering.
• To evaluate the effects of ocular parallax on binocular fusion and monocular depth perception.

Main Methods:

• Developed a custom eye tracker and a high-speed (360 Hz), low-latency (4.8 ms) ocular parallax rendering system.
• Conducted experiments to determine latency thresholds for stable ocular parallax perception.
• Assessed the impact of ocular parallax on binocular fusion and monocular depth perception under free viewing conditions.

Main Results:

• Ocular parallax rendering stability is compromised when latency exceeds 43.72 ms (1.3 D) and 21.50 ms (2.0 D) in binocular viewing.
• Minimized latency enhances binocular fusion.
• Ocular parallax has a limited effect on monocular depth perception under minimized latency conditions.

Conclusions:

• A high-speed, low-latency system is essential for stable ocular parallax rendering in VR/AR.
• Reducing latency significantly improves binocular fusion but has minimal impact on monocular depth perception.
• Further research may explore optimizing ocular parallax for enhanced depth perception in VR/AR displays.