Light field, showing the next big hot spot in the field to create a light field or a cure for "virtual reality disease"

Although virtual reality technology is very hot in recent years, it faces significant problems. First of all, the virtual reality helmet is so cumbersome that it looks stupid to wear it. Secondly, what you see does not match what you feel, and there is another problem that exacerbates this imbalance: the visual convergence of both eyes Focus adjustment conflicts. These have led to "virtual reality sickness."

According to the official website of Wired magazine, at the recent International Conference on Computer Graphics and Interactive Technology (SIGGRAPH), Professor Gordon Wittendan of Stanford University and his colleagues showed a new head-mounted virtual reality. Device that minimizes the problem of visual convergence and focus adjustment conflicts.

The conflict is not big, the consequences are very serious

What is the relationship between the conflict between visual convergence and focus adjustment and the “virtual reality disease”?

When you look at an object, two things happen. First of all, you have to focus on your eye. If the object is very close, your visual axis will naturally focus on it; if it is far away, your visual axis will diverge. This creates a visual convergence; second, the lens of the eye focuses on the object, which is called focus adjustment.

In the natural world, these two roles are combined. In other words, in the real world we rarely experience the conflict between the two. But when you bring a virtual reality helmet such as the Oculus Rift or Samsung's Gear VR, the situation is different.

These three-dimensional helmet devices create a three-dimensional effect by displaying visually offset images for the left and right eyes, respectively. The more the offset between images, the closer the object's spatial imaging point looks, and the farther it is. This makes it possible to use the convergence of the eye to create a spatial sense of depth on the screen. However, the focus adjustment of your eyes is still on the screen.

This means that your eyes should adapt to the screen worn on the head while focusing on further distances, thus creating a conflict between visual convergence and focus adjustment. This kind of conflict is contrary to the physiological laws of human beings. When the eyes are constantly adjusted between these two functions, visual fatigue, physical discomfort and other "virtual reality diseases" will arrive as scheduled.

Light field + special algorithm to effectively coordinate conflicts

This is not just a problem facing the academic circle. Leading virtual reality companies, such as Oculus and Microsoft, know very well that their virtual reality helmets have this problem. Augmented reality company Magic Leap, based in Florida, has also worked hard on this issue.

The team at Wittenstein designed a device that would resolve this conflict. It is a large box with three or four planes showing different parts of the same image. These bits have a lens that changes power and can focus on different parts of the picture.

Unlike ordinary virtual reality devices that use flat images to create a three-dimensional effect, the device creates a light field that simulates the reflection of light on an object in the real world and projects a three-dimensional effect.

The device also includes a two-layer stacked liquid crystal display. The researchers used an algorithm to make different parts of the image appear differently on a two-layer LCD: distant objects would show more detail on the back display, and closer distances would show more on the front display. detail. This perfectly coordinates the conflict between visual convergence and focus adjustment.

According to Witztan, the entire equipment is made up of off-the-shelf components. "The real difference is this algorithm."

Traditional technology may be a "dead end"

Martin Banks, a visual scientist at the University of California, Berkeley, said: "This is a very exciting area of ​​research, and I think this will be the next big show in the display field."

But we still don't expect to use this "artifact" when playing video games soon. Although more planes can bring more realistic images, the field of view of this device is only 90 degrees, and the resolution can not reach the standard of Oculus virtual reality helmet, so its birth does not mean head-mounted virtual reality equipment. The problem of conflict between visual convergence and visual adjustment is completely solved.

Wittstein said that the research team is trying to make the light field by bending the light through the micro lens, but it is more difficult to use this method to improve the resolution of the picture. According to reports, Magic Leap is also doing research on the light field, but it is still unclear about its specific research direction.

Wired magazine's official website commented that Oculus and Samsung's virtual reality devices rely on traditional three-dimensional display. This display technology is great, but it may be a dead end in the face of conflicts between visual convergence and visual adjustment. In order to eradicate "virtual reality disease", this industry may need to start again in the light field.

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