Introduction
Virtual reality (VR) technology has advanced rapidly in recent years. With headsets like the Oculus Quest 2 providing high resolution visuals, immersive audio, and intuitive motion tracking, many people feel like they’ve been transported into another world when using VR. But despite these major improvements, we still have a ways to go before reaching photorealistic VR that is indistinguishable from real life. In this article, I’ll examine how close we are to photorealistic VR by looking at the key areas that need to improve.
Display Resolution and Field of View
The visual experience is arguably the most important aspect of achieving photorealism in VR. Two key factors for visual fidelity are display resolution and field of view.
Display Resolution
Higher resolution displays can render images with more detail and less noticeable pixels. Currently, most VR headsets have displays in the range of 2K to 4K resolution per eye. For reference, the human eye sees the equivalent of about 576 megapixels. So there is still a large gap between current VR resolution and true human vision.
To reach photorealism, some estimates suggest VR headsets will need 16K resolution per eye or higher. This would equal about 32,000 x 16,000 pixels per eye, providing incredibly sharp and detailed visuals. We still have a ways to go, but display technology continues to rapidly improve.
Field of View
Field of view (FOV) refers to how much of the world can be seen at one time. Humans have a FOV of about 210 degrees. But current VR headsets only provide 90-120 degrees FOV. This limited FOV can cause a “scuba mask” effect.
Expanding the FOV requires innovative lens and display designs. Some prototypes aim for 180 degree FOV or more. A wider FOV coupled with high resolution will help deliver truly immersive and realistic VR environments.
Graphics and Rendering
Lifelike graphics and fast rendering speeds are also key for photorealism. The virtual world needs to react instantly to head and body movements. Slow response times can ruin the illusion.
Graphics
Game-like computer generated graphics are steadily improving. But there is still work to be done on lighting, shadows, reflections, textures, physics, animations, and other details that add realism. Ray tracing technology precisely simulates how light behaves in the real world and can greatly enhance realism. AI techniques like deep learning and generative adversarial networks can also help generate highly realistic graphics and animations.
Rendering Speed
No matter how good the graphics, choppy frame rates will diminish the experience. To feel natural, VR needs sustained frame rates of 90 fps or higher. This requires very fast processing and rendering speeds. Foveated rendering, where only the focused visual area is rendered at full resolution, can improve speeds by reducing overall rendering work. Dedicated VR processing chips like the Qualcomm Snapdragon XR2 also aim to provide smooth, stutter-free performance.
Tracking and Input
Accurate, low latency tracking of the user’s head, hands, and body allows for natural interaction and immersion in VR. And comfortable, intuitive input devices are needed.
Tracking
Inside-out tracking using cameras on the headset itself has gotten very good. This allows 6 degrees of freedom motion without external sensors. But there are still occasional tracking errors and jitter. Completely flawless tracking across large spaces remains elusive. Improved sensor fusion algorithms will help headsets better combine data from cameras and inertial sensors.
Hand tracking is also advancing rapidly, removing the need for controllers. But fine finger tracking with low latency still needs work. Full body tracking remains expensive and unwieldy with current external solutions. Internal tracking of eye movements and facial expressions could take immersion to the next level.
Input
Controllers with natural hand presence are the current standard. Yet these still fall short of directly interacting with virtual objects using your real hands. Hand and finger tracking combined with haptic gloves that provide touch feedback could one day allow amazingly natural interaction. Voice and eye tracking input already exists, but needs refinement before becoming viable mainstream options.
Audio Quality
Believable 3D audio is key for presence. Current VR audio is quite good, but still lacks some realism in spatialization and sound propagation. Headsets still predominantly rely on generic head-related transfer functions (HRTFs) for 3D audio.
Personalized HRTF modeling based on scans of an individual’s head and ear geometry could provide more natural and accurate spatial audio. More complex sound propagation modeling to simulate how sounds interact with the virtual environment will add realism. Most current software uses basic approximations at best. There is still room for improvement here.
Comfort and Usability
For VR to replace other media formats, it needs to be comfortable to wear and easy to use for extended periods. Many users still find current headsets heavy, hot, and cumbersome.
Comfort
Advances in display tech should enable thinner, sleeker, lighter headset designs. Improved weight distribution and adjustable fits will also help. Cooling fans and heat sinks may become common to reduce heat buildup around the eyes and face. Lighter, flexible materials could provide a more customized fit. There are also efforts to make VR glasses more like regular glasses. Overall, physical comfort needs more attention as a part of achieving photorealistic VR.
Usability
As VR moves into the mainstream, setup and usage need to become as easy as picking up a phone and putting on headphones. This means intuitive software interactions, inside-out tracking, and wireless connectivity. Hand and eye tracking inputs could allow much more natural menu navigation and system controls. comfort and usability remain ongoing challenges on the path to photorealistic VR.
Conclusion
While great strides have been made recently in VR technology, there are still significant advancements needed before reaching fully photorealistic VR experiences. Display resolution, field of view, graphics capabilities, tracking accuracy, input methods, audio quality, and wearable comfort/usability are key areas that require improvement. With continued rapid innovation in these domains driven by consumer demand and competition amongst tech giants, we may reach photorealistic consumer VR within the next 10 to 15 years. But it’s an immense technical challenge and we still have a long way to go. The next decade promises to be an exciting one for virtual reality.
