VR classification and application and limitations -- Dr. Li She


The three characteristics of 5G network are high speed, low delay and large connection. First, it uses millimeter-wave technology to transmit data at much higher rates than previous cellular networks, faster than the current wired Internet. The second is that the response time is shorter and the network latency is lower. The third is the connection capacity, can be connected to 1 million terminals per square kilometer. These advantages also provide a wide range of application scenarios for 5G technology. One of the most important applications is EMBB, which provides high speed applications such as VR/AR, HD video, holographic projection, etc. Virtual reality is that VR technology integrates computer graphics technology, computer simulation technology, artificial intelligence, sensing technology, display technology, network parallel processing technology and other technologies to create a virtual environment, so as to give people a sense of "immersive".

The general virtual reality system is mainly composed of professional graphics processing computer, application software system, input equipment and demonstration equipment, and one of its characteristics is man-machine interaction. In order to realize the full exchange of information between man and machine, special input tools and demonstration equipment can be designed according to the specific application, which can identify the various input commands of people and provide corresponding feedback information, so as to realize the real simulation effect.

1. Classification of VR

1.1 Desktop Virtual Reality

Desktop virtual reality technology uses personal computers and low-level workstations for simulation, the computer screen is used as a window for users to observe the virtual environment. For example, the virtual reality technology of static image is used to continuously shoot images and videos, and the virtual space of real scene is established by stitching in the computer, which makes the highly complex and realistic virtual scene can be obtained at a very small computational cost, so that the virtual reality technology is realized in the PC end. And VRML (Virtual Reality Modeling Language) is also a common realization means of desktop virtual reality, which is a promising technology applied in the Internet. It uses descriptive text language to describe the basic three-dimensional object modeling, through certain control, these basic three-dimensional modeling combined into virtual scene, when the browser browse these text information, local interpretation, can generate virtual three-dimensional scene, greatly reducing the amount of data transmitted on the Internet. Applications based on this type of technology have actually penetrated into our lives, such as various types of sports watches and some medical devices are the application of this technology.

1.2 Immersive virtual reality

Into virtual reality is a kind of advanced virtual reality system, using special equipment to participants of the visual, auditory and other sensory closed up, and then provide the user with the feeling of a new virtual space, the environment is to use a variety of sensors such as position tracking device, the data glove or other manual input devices built an immersion system. There are three common types of immersion systems. The first is wearable devices, which exchange information rapidly with the body through various measurement sensors and provide three-dimensional virtual perception according to the characteristics of various parts of the body, so that participants can interact with the virtual world in a natural way just like the real world. Another is the projection of virtual reality, the use of visual art combined with computer image data processing functions in the eyes of the participants to create a virtual space, again through the sensors to the movements of the participants in the real-time interaction and virtual space, change the current active state of the virtual space, bring brand-new experience, this technology has attracted the general game company. Another is remote presence systems, which combine virtual reality with robotic control technology, so that when a participant in one place controls a virtual reality, the result happens somewhere else. The participant gets a sense of depth from a stereoscopic display, which is connected to a remote camera. Through the motion tracking and feedback device to track the operator's movement, feedback the remote motion process such as damping, collision, etc., and transfer the action to the remote completion.

1.3 Augmented Reality Virtual Reality

Augmented reality virtual reality is not only the use of virtual reality technology to simulate the real world, simulate the real world. It is more important to use it to enhance the participants' perception of the real environment, that is, feelings that cannot or are inconvenient to perceive in augmented reality. Example of this type of virtual reality is a fighter pilot head-up display, it can install the meter reading and weapons aiming at data onto the transmission on the screen in front of the pilot, it can make the pilots don't have to lower the head to read data in the cockpit instrument, which can focus on staring at the enemy planes and navigation deviation.

1.4 Distributed virtual reality

Distributed virtual reality is to let multiple users connect together through the computer network, at the same time to participate in a virtual space, experience virtual experience together, that virtual reality is promoted to a higher level. At present, the typical distributed virtual reality operating system is combat simulation Internet, which is one of the largest VR projects at present. The goal is to allow various simulators to connect over a vast network, a standard promoted by the U.S. Department of Defense.

2, application

Since the advent of VR technology, it has opened up a vast world for human-computer interaction interface and brought huge social and economic benefits. Many developed countries are vigorously researching, developing and applying this technology, and actively exploring its application in various fields, especially in the development of new weapons and new education.

2.1 Application in weapon equipment research and new weapon display

First, in the process of weapon design and development, VR technology is used to provide advance demonstration and test design schemes, and advanced design ideas are integrated into the whole process of weapon equipment development, so as to ensure quality and efficiency. In addition, for some impossible experiments or high experimental cost of weapon development work, VR system can also be completed, to provide conditions for improving weapons.

Secondly, developers and users can easily get involved in the whole process of system modeling and simulation test by using VR technology, which can not only speed up the development cycle of the weapon system, but also reasonably evaluate its combat effectiveness and the rationality of its operation, so as to make it closer to the actual combat requirements.

Thirdly, VR technology is used to simulate the battlefield environment, technical performance and use efficiency of weapons and equipment in the future high-tech war, which is conducive to the selection of key weapon and equipment systems and the optimization of their overall quality and combat effect.

Fourth, many weapon suppliers use the network to display various capabilities of weapons using VR systems.

2.2 New Education

First, the virtual campus uses VR technology to simulate the campus environment. At present, the main browsing function is given priority to. With the emergence of a variety of flexible browsing methods in a new form, the virtual campus is attracting everyone's attention in a new attitude. (Virtual Campus of Hangzhou Institute of Electronic Technology)

Secondly, in higher education, especially in the teaching of science and engineering courses, the introduction of VR technology has made a qualitative breakthrough in teaching, making the classroom more vivid and able to complete some interactive experiments, and creating a virtual education environment. For example, the Virtual Reality and Multimedia Research Laboratory of Zhejiang University CAD&CG State Key Laboratory has developed a virtual character based electronic learning environment (ELVIS) in the European Union science and technology project, which is used to assist primary school students aged 9 to 12 years to create stories.

Third, distance education. VR technology breaks through the limitations of physical time and space and effectively uses the characteristics of shared resources. It can also create virtual teachers and experimental equipment, etc., which has a great development prospect. For example, the Distance Education College of China Radio and Television University has invested a lot of manpower and material resources to adopt the game image engine based on the Internet and integrate the actual functions of the Network College into the graphics engine.

Fourth, special education. VR technology is a kind of interactive form oriented to nature, which has a special influx for some special education. The "Chinese Sign Language Synthetic System" developed by the Institute of Computing Science, Chinese Academy of Sciences, adopts the 3D motion data acquisition method of sign language based on motion tracking, makes use of data gloves and spatial position tracking and positioning equipment, and can obtain accurate 3D motion data of sign language. Use this method. The Chinese sign language synthesis system has completed the data collection of 5,596 words of sign language, forming a three-dimensional display database of Chinese sign language, which has facilitated the life of many deaf and mute people.

3. Development prospects and limitations

VR technology field was born in the United States, originally to meet the needs of national defense and aerospace, with the rapid development of computer technology, especially graphic display technology, in the actual production has more applications. Its main development trend is toward the direction of production convenience and providing the sense of entertainment experience. But at the same time, as VR technology is an emerging science and technology, its development is also dependent on the development of other technologies, subject to the current restrictions of other science and technology. There is still a certain gap between the ideal situation that people pursue in their hearts. Further improvement and perfection are needed in terms of immersion and interactivity, mainly including the following aspects:

(1) Limitations of hardware devices. The related equipment is not convenient to use and the effect is not good. The variety of hardware equipment also needs to be further expanded and the cost of equipment is a major limitation.

(2) Limitations of software. Most of the VR software generally has strong professional language, poor versatility and poor usability. At the same time, the effect that software can realize has received the time and the space greatly influence, many calculate large and many related theories are not mature, for example, in the new sensing and the perception mechanism, the geometric and the physical modeling machine method, etc.,