2016 is known as the first year of VR. The global hardware, content and capital giants have made frequent moves. VR devices will be the next computing platform after computers and mobile phones. By 2025, the hardware revenue of VR and AR will reach 110 billion US dollars. Since last year, including Facebook, Samsung, Sony, HTC and even Alibaba The VR strategy has been laid out in the whole line to seize the market of 100 billion scale. The instantaneous outbreak of industrial scale is bound to promote the establishment of VR industry norms and healthy ecology. According to the “global VR technology standard”, it is the first time to define the three key technical standards of VR products: less than 20ms delay, more than 75Hz refresh rate and more than 1K gyroscope refresh rate, which will become the rules of the new VR industry.
According to the latest global virtual reality headgear forecast report of strategy analytics, the global virtual reality (VR) headgear shipment in 2016 was about 12.8 million. At the same time of the strong industry scale and the rapid growth of the market, it is inevitable to have a shadow, including different forms of hardware products, unclear key parameters, extremely poor sense of experience, price polarization and so on. Driven by the essence of “pursuing profits”, the industry is actively hyping the concept and confusing the public.
As the next computing platform to change the world, the use experience of VR products will directly affect the process of the whole industry. The latest global VR technology standards have made clear requirements for product delay and refresh rate, which will quickly standardize the VR industry and enhance consumer market awareness.
VR experience actually requires a complex technological process, from sensor acquisition, transmission, game engine processing, hardware rendering, LCD pixel color switching, and finally to the human eye to see the corresponding picture. Every step in the process will produce a latency, which we call latency. Thus, three key parameters that VR products must support are derived: 20ms millisecond delay, picture refresh rate above 75Hz and gyro refresh rate above 1K.
VR delay refers to the matching degree of head movement and visual perception of VR devices. Human biological research shows that the delay of head movement and visual field return must be less than 20 ms, otherwise it will produce a sense of visual drag and lead to strong vertigo. According to the algorithm of the above three indicators, VR standard analysis is as follows:
At present, the TFT screen delay itself is higher than 20ms MS, so only OLED or better screens are considered in VR product hardware. Let’s take a look at the general OLED screen refresh rate of 60Hz, and use the formula of 1s / 60Hz =The delay of each eye is 8.3 MS, which is the hard delay that the VR device can’t avoid. To achieve a better VR experience, we need to consider the delay of “OLED screen delay 2ms” + “anti distortion and anti dispersion algorithm delay 3MS” + “1K refresh rate gyroscope delay 1ms precision plus data reporting delay 1ms” 2ms.
The GPU performance speed of VR products must be within 20ms-8.3ms-2ms-3ms-2ms, that is, 4.7ms MS to complete all kinds of rendering and return to the human eye; according to the current chip GPU performance calculation, when the screen refresh rate is 75Hz or above, the experience effect of VR products is more smooth, so the ability of chip GPU and the matching depth algorithm are the key factors to determine the VR product experience.
Improving the refresh rate is the general trend to improve the VR experience. The higher the refresh rate is, the smaller the VR delay is, the better the flicker and delay of the screen will be, and the better the experience will be. VR products with lower than 60Hz refresh rate screens or even TFT screens can not improve the delay, and the experience is extremely bad and vertigo is strong, which is defined as defect level VR products by the industry. Therefore, VR devices with refresh rate between 75Hz and 90hz are the entry-level standard indicators; VR devices with refresh rate higher than 90hz are medium level VR products.
Generally, VR industry divides it into three categories: mobile head display, PC head display and all-in-one head display. In order to get a better experience, no matter what form of VR, the performance of GPU is required to be very high. GPU determines whether it can meet the two key indicators of VR, i.e., delay within 20ms and millisecond and support the refresh rate of 75Hz ~ 90hz screen.
GPU performance quantification is generally based on the industry standard “triangle filling rate”. According to the malit760mp4 performance of the mainstream entry-level VR GPU in the market, the operating frequency of 28nm nano HPM manufacturing process is 600MHz, the output rate is more than 300 million triangles per second, and the filling rate is 2.6g pixels per second. Therefore, GPU performance must reach 300m per second, i.e. 300 million triangle output rate, in order to meet the requirements of entry-level VR products. All chips with GPU triangle output rate lower than 1.39 billion, whether the CPU is four core or eight core configuration, do not meet the industry standard of entry-level VR products, let alone support the mainstream mid-level VR market.
During this period, the technical standards of VR industry will play the role of purifying the industry. It will accelerate the elimination speed of brands and solution providers with poor experience and affecting the development process of VR industry. Industry analysis shows that in the process of VR hardware development, optical technology, immersive solution, structural design with optics, SDK, and developer tools are integrated solutions. If the most basic technical indicators cannot be achieved, the experience can not be done well, and the VR industry ecology is out of the question.