Technology

Kirill Yurovskiy: How to choose a VR system

One of the most anticipated gaming technologies – VR – is slowly becoming a reality. More and more VR-systems are produced, their capabilities are growing every month, and their prices do not look prohibitive anymore. How to choose a VR-system, which characteristics are important and which are not? The answers are in this article.

Image parameters

It would seem, what is so special about the image of VR glasses? Just another display of another gadget with familiar characteristics and the principles of their selection. But no, there are some subtleties.

Resolution

As usual, the higher the better. It is true that in other gadgets the resolution has already surpassed the limit beyond which individual pixels become indistinguishable. But in the case of VR glasses, most users complain about the “mosquito net” effect – not only the pixels are clearly distinguishable, but also the space between them. 

And this despite the fact that the resolution of most glasses at first glance looks good. From 2880×1600 to 4320×2160 – better than the top smartphones. What’s the matter?

The fact that the glasses claim to capture the entire field of view, rather than a small part of it, as in the case of smartphones. The selectivity of the average person’s vision is about 1 angular minute, and the field of view is 210 degrees horizontally and 140 vertically. It turns out that the resolution at which the pixels will start to merge is 12600×8400! And this at the size of the screen no larger than a normal smartphone. So far, there are no such displays or graphics cards. And pixels in VR glasses will be visible on any model.  

So now resolution in VR glasses is one of the most important factors. Here we can draw an analogy with monitors and graphics cards in the 90s. The main gaming resolution back then was 320×200. This was the resolution millions of people were playing Doom. And what a breakthrough on this background resolution seemed 640×480. With glasses it is almost the same – increasing the resolution has a big influence on the effect of the picture. Much more than, for example, in video – the transition from 2K to 4K. Source of text is here 

Viewing Angle

One way to reduce the resolution requirement is to reduce the viewing angle. It is necessary to reduce the horizontal viewing angle from 210º to 100º and you need only 6000 pixels horizontally instead of 12600. Producers say it is quite acceptable, because the field of view, in which a person sees objects more or less clearly, is even less – only 60º. But when you reduce the angle of view, there is an unpleasant feeling as if you are looking at the world around you through a tube or a diving mask. This sensation is called the diving mask effect.

But if you do not squint your eyes, it begins to show only if the viewing angle is less than 120º. That is why the best VR-glasses have a viewing angle of 120º, and the top models have 140º and even more – up to 200º. But don’t forget – the higher the viewing angle, the higher the resolution should be. 

Screen refresh rate

Here everything is standard. The higher the refresh rate, the smoother the movement of objects on the screen. But do not prioritize this parameter:

  • Firstly, it affects the immersion effect less than the resolution or viewing angle.
  • Secondly, the difference between the refresh rate of 75Hz and 100Hz will only be noticeable when the video card can steadily deliver more than 75 FPS. If this is not the case, it is better to spend on a video card upgrade than to chase a high refresh rate.

Sensors and controllers

VR systems are not just about 3D video. It’s also about interacting with the world around you. Without this, it is impossible to achieve full immersion. All interaction can be divided into two parts:

  • Changing the image when you move, turn and tilt your head;
  • Tracking movements of the player’s arms, legs and body.

All of this is provided by sensors located in the helmet or in the base stations, controllers and trackers.

Built-in sensors

  • The gyroscope tracks the position of the VR helmet relative to the earth’s surface. When you tilt your head, the image in the VR glasses tilts in sync. The gyroscope makes this happen.
  • The accelerometer (or rather, a set of three accelerometers) tracks the helmet’s movements in space. The accelerometer and gyroscope work together to provide accurate and quick recognition of any head movements.
  • The magnetometer tracks the position of the helmet relative to the Earth’s magnetic field. It is typically used to improve accuracy for complex head movements. 
  • The proximity sensor measures the distance from the lens to the user’s face. On simple models, it is used simply to determine when the glasses are on. On more complex models, the lens can adjust to the distance to the eyes for greater image clarity.
  • Tracking sensors are designed to track real-world objects and link them to the virtual world. So, with the help of the tracking sensor, the glasses can warn about the dangerous approach to the wall or furniture. Also with the help of tracking sensors the position of controllers and trackers is fixed.

Base stations included

Tracking sensors can be located on the helmet itself. This simplifies (and cheapens) the system, but then the sensors have extensive blind spots. For example, such a sensor will “lose” the controller if you put your hand behind your back or simply move it sideways while looking the other way.

Another principle of tracking is to install sensors on base stations located on the sides of the player at a certain distance. With such a system, all movements are tracked more clearly and accurately, and controllers are not missing from the system’s attention at any location relative to the player. This option is preferable, but the price is higher. In addition, you need to find a place in the room for the base stations.

Controllers and trackers

A VR system controller is not really a regular controller. Yes, its functions are the same as those of a game controller. By pressing buttons on it, you activate certain game features. But the most important thing about them is that they exist in both real and virtual worlds. Sensors track the position of the controllers and render them in VR. You can use them to highlight objects in the virtual world, point at them, move them around, etc.

A tracker is a specialized controller that tracks the position of human body parts and transmits them to the system. Using a tracker, it is possible to read the position of hands and feet, fingers. With its use, there is no need for a controller. For example, it is no longer possible to pick up an object by pressing the corresponding button on the controller, but simply by moving your fingers. This contributes to immersion in virtuality, but significantly increases the requirements for computing power of the PC and the game itself. So far there are not many games that fully support trackers. And the cost of a VR-system with trackers is very impressive.

Synchronization with devices and minimum requirements

Most VR systems are not independent devices. They only display a prepared image and transmit information about their position. The processing of this information and the preparation of the image takes place on some central device, which can be a smartphone, a game console or a PC.

Synchronization with a device

  • Smartphones. It should be understood that the processing power of even the top-of-the-line smartphones is far inferior to the PC. Therefore, you should not expect from such VR-glasses capabilities, as on the bundle PC + VR-system. The image quality will definitely be worse, because smartphones do not have powerful graphics cards with 3D support. 
  • Gaming console. VR-glasses that are paired with a gaming console are quite comparable with computer glasses. The main difference is that such VR-glasses can only work with the “native” console and you can play only original games for this platform. But there are no problems with compatibility and resource requirements.
  • PC. The top models and the main market for games with virtual reality support is still focused on computers. But the computer to the computer is different, and virtual reality – a very resource-intensive thing. So on many PCs glasses will “slow down” and some will not work at all. When choosing glasses for the PC, be sure to pay attention to the minimum requirements.

Minimum OS Requirements

It’s simple, if you have an earlier version of the system than the minimum requirements, the VR system will not work. Switch to the new OS.

Minimum requirements for memory, video card and processor

This is like the minimum requirements for games. If points require a minimum GTX 970, it doesn’t mean that everything will “fly” if you have this graphics card. It means that simple games will work, but in more complex games you will have to play on minimal settings or enjoy a “slideshow” in dynamic scenes. The same applies to memory and to the processor. If you are just going to buy a PC to get acquainted with virtuality, immediately “aim” at a couple of notches higher than the minimum requirements.

Choices for VR systems

If you want to play 3D games from your smartphone, and the capabilities of simple 3D glasses are no longer enough for you, look at VR systems that pair with your smartphone. But keep in mind that at an “adult” price, they are in many ways inferior to systems that interface with PCs or game consoles.

The degree of immersion in virtuality depends largely on the quality of the picture. So for the best effect, choose among models with higher resolution and viewing angle.

The presence of controllers in the kit allows you to interact with the objects of the game world, making it almost real.

If you have enough space in your game room, choose among models with base stations included. Such VR systems are much better at tracking the position of controllers and trackers.

If you do not have the most productive computer, and you do not plan to make an upgrade, choose among not the most demanding models.

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