Problem description:
I hope I can provide some knowledge about virtual reality, preferably VRML, thank you!
Analysis:
Vrml virtual reality technology 1
Virtual reality is a more ideal form of man-machine interface between computer and user. Usually, users wear helmets (head-mounted displays that display stereoscopic images) and hold sensing gloves, as if they were in an imaginary world, roaming in a virtual environment and allowing them to operate the "objects" in it. Compared with traditional computers, virtual reality system has three important characteristics: proximity, interactivity and imagination. Virtual reality technology has a wide range of potential applications, such as national defense, architectural design, industrial design, training and medical treatment. For example, architects can use virtual reality technology to provide customers with three-dimensional virtual models, and surgeons can also try a new surgical operation on three-dimensional virtual patients.
After more than 20 years of research and exploration, virtual reality technology went out of the laboratory in the late 1980s and began to enter the practical stage. At present, a few developed countries in the world have begun to widely use this high-tech in the economic, artistic and even military fields, and have achieved remarkable comprehensive benefits. According to foreign reports, the US Army 1994 "Louisiana 94" combat exercise was conducted using virtual reality technology. This exercise not only tested and demonstrated the laws and regulations, tactics and force composition formulated by the US Army, but also made it more in line with the operational requirements of 2 1 century, and also saved nearly $2 billion in exercise funds.
So, what is virtual reality technology? Simply put, it is a new technology that people use computers to generate realistic three-dimensional virtual environment and use sensing equipment to interact with it through natural skills. It is completely different from the traditional simulation technology, which combines the simulation environment, the visual system and the simulation system into one, and uses sensing equipment such as helmet display, graphic glasses, data suit, stereo headphones, data gloves and pedals. Connect the operator with the computer-generated three-dimensional virtual environment. Through the interaction between the sensing device and the virtual environment, the operator can obtain a variety of senses such as vision, hearing and touch, and change the "involuntary" virtual environment according to his own wishes. For example, the computer virtual environment is a building with all kinds of equipment and objects. The operator can walk around the house, check through various sensing devices, open and close doors and move objects as if he were there. If you are dissatisfied with the design of the house, you can change it at will. Obviously, it is much easier and cheaper to use this virtual reality technology to modify the design of buildings, machinery and weapons, as well as to conduct technical operation training and military exercises.
Once virtual reality technology is applied, it shows attractive prospects to people, so it is favored by the military circles of various countries. From the early 1990s, the United States took the lead in applying virtual reality technology to the military field, mainly in the following four aspects: First, the virtual battlefield environment. That is, through the corresponding three-dimensional battlefield environment graphic image library, including combat background, battlefield scenes, various weapons and equipment and combatants, a dangerous and almost real three-dimensional battlefield environment is created for users. In order to enhance their sense of existence and improve the quality of training. The second is to conduct individual simulation training. Let soldiers wear data suits, helmet displays and data gloves, select different battlefield backgrounds by operating sensing devices, input different disposal schemes, enjoy different combat effects, and exercise and improve their technical level, quick response ability and psychological endurance as in actual combat. For example, the flight training simulator developed by the United States Air Force with virtual reality technology can produce visual control, can handle three-dimensional real-time interactive graphics, and has sound and touch other than graphics. It can not only manipulate and control the aircraft in a normal way, but also deal with various situations outside the aircraft in virtual reality, such as the threat of balloons and the launch trajectory of missiles. Third, joint exercises of various services and arms should be carried out, and a "virtual battlefield" should be established, so that the two sides participating in the war can be on the spot, and according to various situations and changes in the virtual environment, "deploy troops and dispatch troops" and "fight with wits" to conduct "real" confrontation exercises. The fourth is to conduct commander training. Using virtual reality technology, the battlefield panorama is synthesized according to the reconnaissance intelligence data, so that the trained commander can observe the enemy and the battlefield situation through the sensing device, thus judging the enemy situation and making correct decisions. The "Virtual Battleship Command Center" developed by the US Navy can realistically simulate an environment that is almost completely similar to the real battleship command center, and has vivid visual, auditory and tactile effects, so that the trained officers are immersed in the "real" battlefield.
Of course, virtual reality is a young science and technology, and there are still many problems to be solved. For example, in a computer-generated virtual environment, the computer must update the three-dimensional image every time the operator turns his head. Because the updated data is too large, the computer can't complete the real-time operation. This leads to system lag. For another example, the visual action signals generated by the virtual reality simulator of the US Air Force are also different from people's feelings, which is easy to make people feel headache and dizziness.
But after all, virtual reality technology has opened up a new field, with great development potential, which will be improved day by day with the passage of time, and its application in the military field will be more and more extensive and its role will be greater and greater.
Virtual reality world
The emergence of the World Wide Web produced hypertext.
Markup language (HTML). In this way, text and graphics can be displayed at the same time.
Displayed on the same page, and CGI (Universal Gateway Interface)
With the popularity of the World Wide Web and people's interest in Network Day.
With the increasing demand, new network languages need to be constantly produced.
The appearance of Java enables people to enjoy animation directly on the web page.
Java language is an object-oriented language, and people can set actions on the page.
Draw, and use Perl and c programming to generate executable code.
At present, the popular text languages are HTML and SGML (standard
Generalized markup language). Are described with labels.
Describe the different elements in the data structure.
Recently, a new network language VRML (Virtual Reality) appeared.
Modeling language). It is a model language for descriptive purposes.
How objects are presented on the Web. Like HTML, VRML has it.
A description language interpreted by browsers, except that VRML is not described as
Page format, but described as the layout of 3D environment and target.
The difference between HTML and VRML and the difference between the blueprint of the building and its model.
The same is true.
1. What is virtual reality (VR)?
Virtual reality is a three-dimensional environment simulated by computer. Users can walk in.
Environment and manipulate objects in the system. Virtual reality is the most important and attractive place.
It is real-time and interactive. Through the computer network, multiple users can participate.
The same virtual world has the same visual and auditory feelings as the real world, and even
More colorful.
What is described above is the future virtual reality world, not the present virtual reality.
The real system is far from meeting people's requirements. First, the transmission speed of the network is not good.
Meet the real-time transmission of video and data exchange of large amount of information; Followed by virtual reality.
The equipment actually used is in the development stage and far from being popularized.
2. Hardware equipment required for virtual reality
Virtual reality and multimedia are essentially different. Multimedia is on the screen.
A series of two-dimensional images are displayed in sequence, while virtual reality uses length, width and height, and
Display its three-dimensional image from all directions. Another important difference between them is that
Hardware equipment.
Ordinary computer interactive equipment includes keyboard, mouse, operation sign, etc. , and then
Multimedia system (keyboard, mouse,
Computers and installed monitors). The tracker is mechanical and super alive.
, magnetic induction, light induction and passive, its dexterity far exceeds the general cross.
Common equipment is much superior. The "helmet" consists of a display, an optical system and a stereo.
Box and tracking system.
Three. Examples of existing network virtual reality systems
1.SIMNET It is a system used for military exercises, belonging to the US military.
SIMNET, which aims to reduce the training cost of tank troops, is the first large-scale one.
An example of scale network VR can adjust the modulus of the full-motion image near 1000.
Shaper.
2.VR games Many game companies have partially virtualized their products.
The real environment, especially on the local area network, makes real-time and interactive become a reality.
.
4. Virtual reality language
VRML (Virtual Reality Modeling Language) is virtual.
The establishment of the environment provides a standard and synthesizes the scene description language of the existing three-dimensional software.
The advantages of strictness. It defines basic elements, vertices, lines and faces, and coordinate transformation.
There are scaling, rotation and translation,
And has an optimized data structure.
Verb (abbreviation for verb) VRML browser
If VRML is a language, obviously VRML browser is.
Indeed, the main function of VRML browser is to read VRML code.
Archive and interpret it as a graphic image.
At present, there are many kinds of VRML browser software, such as Netscape.
Live3D
(Landscape/Product/Product/Navigation/
Live3d/index), WebFX of paper software company.
(paperinc/), SGI and template graphics
Cyberspace of Sofare
(web space . SGI/web space/whats new/)，
The worldview of Invista Software Company
(Webmaster /vrml/) and Microsoft's
Virtual resource manager
(Microsoft /windows/ie/vrml) and so on.
They basically realize the transformation effect of objects, such as illumination, angle transformation, mode and so on.
Paste, cut, shadow, projection, collision? Badger?
6. Create a VRML file
The basic objects of VRML language are spheres, cones, cylinders and cubes.
, text, etc. provide convenience for creating scenes, such as the establishment of a real sphere below.
For example.
# VRML V 1.0 ASCII
Delimiter {
Material {diffuse color 1 0 0}
# Red
Sphere {}
}
At present, many model softwares create VRML files, which reduces people's attention to VRML.
Fear of language, there are many softwares that can put other 3D files.
Convert to VRML files, such as 3DS, RAW, etc.
it.sohu/webcourse/webmonkey/ 1multimedia/vrml/