Virtual Reality Challenges

Consumer-level virtual reality is steadily becoming lighter, cheaper, and more polished, but it still has a number of technical hurdles to overcome to truly reach the potential of the mass consumer. Fortunately, the renewed interest in virtual reality in the past few years has led to an influx of investments in the field, which should speed up the discovery of solutions. The following information explores some of the major problems facing virtual reality today and how some companies are working to solve them.

Virtual Reality Challenge 1: Simulation Disease
Early HMDs generated widespread user complaints of motion sickness. This problem alone was enough to cripple early VR mass consumer devices like Sega’s VR and Nintendo’s Virtual Boy. It’s a problem that modern headphone manufacturers are still dealing with.
Motion sickness can occur when there are inconsistent signals between the sense of vestibular movement in your inner ear and what your eyes see. As your brain senses that these signals are inconsistent, it then assumes your body is sick, likely due to poison or some other affliction. At this point, your brain may decide to induce headaches, dizziness, confusion, and nausea. Using a virtual reality headset can lead to a type of motion sickness that doesn’t necessarily involve any real movement; Researchers called it mimicry disease.
There are a number of ways to combat mimesis, including some unconventional ones. One study conducted by Purdue University’s Department of Computer Graphics Technology suggested adding a “virtual nose” to every VR application to add a stabilizing effect to the user. Virtualis LLC markets this virtual nose, calling it nasum virtualis. Embedding the nose in the user’s field of view serves as a stable reference point to alleviate VR sickness. Your bodily nose appears in your field of view in real life, but you often do not realize it there. Likewise, most users in the Virtualis studies did not even notice a virtual nose in VR, but reported a 13.5% reduction in disease severity and an increase in time spent in the simulator.
The most effective way that VR developers can combat simulated disease is to reduce the latency between a user’s physical movement and the headset’s response. In the real world, there is no latency between the movement of our heads and the visual response to the world around us. Reproducing this lack of latency in the headphone is critical.
With the prevalence of virtual reality on low-power mobile devices, it is more important than ever to keep the frames per second (FPS) that each headset can display as high as possible. Doing so enables the visual elements of the headset to stay in line with the user’s movement.
Here are some other suggestions for avoiding simulated sickness when creating or using virtual reality applications:
1. Make sure the headset is set correctly. If the virtual world looks blurry when you try the headset, then most likely the headset needs adjustment. Most headphones allow users to adjust the fit of the device and distance from their eyes to eliminate any distortion. Make sure your headset is set correctly before entering any virtual reality experience.
2. Sit down. For some people, the feeling of stability that sitting provides helps them overcome motion sickness.
3. Mark the text as legible. Avoid reading or using small font text in VR, and keep text use to a minimum (only a few words at a time).
4. There is no unexpected movement. When developing, don’t move the camera programmatically for no reason. The user must feel that the movement is caused by his movement or is triggered by the interaction.
5. Avoid acceleration. It is possible to move the virtual cameras without causing the simulation sickness, but this movement should be smooth. Avoid speeding up or slowing the user down when movement in the virtual space is required.
6. Always keep track of the user’s movements. Do not invert the camera to reverse the user’s movement or stop tracking the position of the user’s head. The user’s view should be refreshed with their head movement.
7. Avoid items with a fixed width. Fixed-width elements (elements that do not change when the view changes, such as a pop-up informing the user of something in the middle of the screen or a vertical display [HUD]) are very common in 2D games today. However, this mechanism does not work well in virtual reality, as it is not something that users are accustomed to in the real world.
As hardware becomes more powerful, emulation due to lower frames per second, in theory, should become less common. The more powerful the device, the better the ability to maintain visuals and movement of the virtual world tracks the user’s physical movement, reducing the main cause of simulation sickness.
However, even though we have far exceeded the processing power of old computers, we still encounter programs that often run slower than games of 20 years ago. In general, the more powerful our devices are, the more we require them. Better pictures! More items on screen! Bigger fields of vision! More effects! Knowing the possible causes of mimicry disease should help you overcome these issues should they arise.

VR Challenge 2: Screen Door Effect
Put on any old VR headsets, or some current smartphone-powered VR headsets, and look closely at the image produced in the headset. Depending on the resolution of the device you’re using, you may notice “lines” between the displayed pixels. As a kid, you might have noticed the same thing if you sat too close to your old TV. This problem is called the “screen door effect”, for its similarity to looking at the world through a screened door. Although this problem has long been resolved for today’s Ultra HD TVs, it has been reintroduced in some VR headsets.
This effect is most pronounced on lower-resolution displays, such as old headphones or some smartphones, which were never meant to be used in the first place as virtual reality machines, placed inches from your nose and magnified by optical lenses.
Various proposals were made to resolve this issue. For example, LG suggested placing a “light diffuser” between the screen and the lenses, although most people would agree that the real fix would be higher-resolution screens. High-resolution screens should mitigate the effect of a screen door, as is the case for a television, but will require more processing power to run. As with mimesis, the hope is that the better the hardware, the less likely this effect will be. With a bit of luck, the screen door effect should become a relic of the past in the next generation or two of VR headsets.

Virtual Reality Challenge 3: Motion in Virtual Reality
Transitioning through the digital environment of virtual reality remains an issue. High-end headphones, such as the Vive and Rift, allow users to be tracked across the room, but not much further than that. Anything more than that requires some sort of movement mechanism built into the app itself, or specialized hardware beyond what’s likely available to most consumers.
Movement over large distances in virtual reality is likely to be an ongoing logistical problem for application developers. Even using some of the previously mentioned solutions, movement in VR that is not compatible with physical movement can lead to simulated sickness in some users. And even if you can guarantee an omnidirectional treadmill for each user to track their movement, there are often large distances that users won’t want to cover while walking. In addition, users with limited mobility may not be able to traverse walking distances. Mobility is a problem that hardware and software developers will need to work together to solve. There are solutions available.

Virtual Reality Challenge 4: Health Effects
Health risks are perhaps the biggest unknowns on this list. Oculus Rift health and safety guidelines caution against its use if the user is pregnant, elderly, tired, or has heart disease. They also warn that users may experience severe dizziness, seizures, or fainting. Things look scary! There are also many unknowns regarding the long-term health effects of virtual reality. Researchers have yet to study the effect of long-term use of VR headsets on eyesight and the brain.
Preliminary studies have generally shown that most adverse health effects are short-lived, with little lasting impact on the user. However, as users begin to stay in the VR space for longer periods at a time, more studies will be needed to discover any long-term effects of VR use.
Meanwhile, virtual reality companies appear to be erring on the side of caution regarding the potential long-term effects. As Sarah Sharples, chair of the Chartered Institute of Ergonomics and Human Factors, said in an interview with The Guardian, “There are certainly potential negative effects of using virtual reality. The most important thing we should do is be careful and rational. But we should not let that stop us from taking advantage of The huge potential that this technology offers as well.”

VR Challenge 5: Deconstructing the Market
One recent concern concerns the VR market as a whole. The mobile market (specifically the cheapest app, Google Cardboard) has the advantage of massive reliance on high-end headphones (see Table 2-3). And perhaps for good reason. It’s easier for a consumer to buy a low-cost $20 mobile VR headset than to save a few hundred dollars for a high-end model.
As expected, lower quality headphones tend to deliver low-key experiences. The user may dismiss an inferior VR system as more than just a game, believing that it represents the current level of immersion in VR, when nothing could be further from the truth. However, perception can often become a reality. Could the proliferation of low-end VR applications harm long-term adoption of VR, fragmenting its market?
It’s possible that the lower-end device sales numbers have caused some companies to stand up and take notice. Many manufacturers seem to be focusing on a multi-level strategy for the next generation of headphones, offering experiences ranging from the low end to the high end for consumers. For example, Oculus co-founder Nate Mitchell claimed in an interview with Ars Technica that Oculus will focus on a three-head strategy for the next generation of consumer headphones, with the standalone Oculus Go releasing in 2018, as a lower-end standalone device, followed by Oculus Santa Cruz, a mid-tier headphone experience. Similarly, HTC released the HTC Vive Pro as a high-end device, with the standalone HTC Vive Focus (released in China) focusing more on the mid-tier market.
In the long term, there is likely to be a broad enough market base to support all forms of VR. With the advent of the next generation of headphones, it will be interesting to see which devices are the most successful with consumers. The near future is likely to lead to a rise in headphones for mid-range mobile devices, while external headphones based on PC cater to those who use all the high-end devices. The latter is a smaller demographic, but is willing to spend more to get the best-in-class experience that virtual reality can offer.