An introduction to Virtual Reality (VR)

By the rapid growth of technology, Virtual reality (VR) has become an emerging implement which allows a user to interact with a computer-simulated environment, whether that environment is a simulation of the real world or an imaginary world. The main points of VR are full immersion and inside participation. A simulation technology without immersing user as an insider in a simulated environment is not a VR technology. Most current virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special or stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones.

Some advanced, haptic systems now include tactile information, generally known as force feedback, in medical and gaming applications. Users can interact with a virtual environment or a virtual artifact (VA) either through the use of standard input devices such as a keyboard and mouse, or through multimodal devices such as a wired glove, the Polhemus boom arm, and omnidirectional treadmill. The simulated environment can be similar to the real world, for example, simulations for pilot or combat training, or it can differ significantly from reality, as in VR games. In practice, it is currently very difficult to create a high-fidelity virtual reality experience, due largely to technical limitations on processing power, image resolution and communication bandwidth. However, those limitations are expected to eventually be overcome as processor, imaging

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and data communication technologies become more powerful and cost-effective over time.

Virtual Reality is often used to describe a wide variety of applications, commonly associated with its immersive, highly visual, 3D environments. Lastly, it is introduced that VR falls into three main categories: 1) text-based, 2) desktop and 3) immersive VR. Text-based networked VR involves real-time environments described textually on the Internet where people interact by typing commands and "speak" by typing messages on their computer keyboards. This has been valuable in distance education. Desktop VR is an extension of interactive multimedia involving three-dimensional images and added to the experience of interactive multimedia without being considered immersive.

Immersive VR, involves a mixture of hardware, software and concepts that allow the user to interact with a three dimensional computer generated "world"

Features of Virtual Reality [5]

Winn and Bricken suggested 6 features for pedagogy:

1. Students can obtain a definite direction in learning through VR

2. Since VR is an overall operation, students can fully immerse themselves in the learning environment.

14 number of important changes in human life and activity. Virtual reality will be integrated into daily life and activity and will be used in various human ways.

 Techniques will be developed to influence human behavior, interpersonal communication, and cognition.

 As we spend more and more time in virtual space, there will be a gradual

“migration to virtual space,” resulting in important changes in economics, worldview, and culture.

 The design of virtual environments may be used to extend basic human rights into virtual space, to promote human freedom and well-being, and to promote social stability as we move from one stage in socio-political development to the next.

Heritage and Archaeology [5]

The use of VR in Heritage and Archaeology has enormous potential in museum and visitor centre applications, but its use has been tempered by the difficulty in presenting a 'quick to learn' real time experience to numerous people. Many historic reconstructions tend to be in a pre-rendered format to a shared video

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display, thus allowing more than one person to view a computer generated world, but limiting the interaction that full-scale VR can provide.

Mass media [5]

Mass media has been a great advocate and perhaps a great hindrance to its development over the years. During the research “boom” of the late 1980s into the 1990s the news media‟s prognostication on the potential of VR — and potential overexposure in publishing the predictions of anyone who had one (whether or not that person had a true perspective on the technology and its limits) — built up the expectations of the technology so high as to be impossible to achieve under the technology then or any technology to date. Entertainment media reinforced these concepts with futuristic imagery many generations beyond contemporary capabilities.

Architecture and Real Estate [5]

Architects use this technology to create virtual plan of their designed stuffs where people can walk through, feel and then decode. It‟s an accurate idea how your house will look like after completion.

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Surgeons have tried using virtual reality technology to not only educate and train, but also to conduct remote surgery with the help of robotic devices.

3.1.2 The three essential factors for Virtual Reality [6]

According to the publishing “Virtual Reality Technology” by Grigore Burdea and Philippe Coffet, they raised three essential factors for virtual reality:

1. Imagination:

It has been proposed that the whole of human cognition is based upon imagination. When sense organs are stimulated, messages will be transmitted to the nervous system and produce illusion which is like imitating the real world.

2. Immersion:

Immersion is the state of consciousness where an immersant's awareness of physical self is diminished or lost by being surrounded in an engrossing total environment; often artificial. This state is frequently accompanied by spatial excess, intense focus, a distorted sense of time, and effortless action. In this way, when users are fully immersed into the virtual environment, they may highly enhance the efficiency of the work and will be benefitted a lot.

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3. Interaction:

Interaction is a kind of action that occurs as two or more objects have an effect upon one another. The idea of a two-way effect is essential in the concept of interaction, as opposed to a one-way causal effect. Combinations of many simple interactions can lead to surprising emergent phenomena. Interaction highly applied in Virtual Reality in the 3D area. Through this features, the machine can detect the activities with humans and carry on any further communications and motions, and thus create a better working environment.

3.1.3 Civil Engineering Problems and Solution by VR [7]

Even though the computer gives us a lot of helps as mentioned above in load-acting responses, safety checks and CAD draft drawings, with civil engineering trend to complex and requirement to project contents rises, it cannot satisfy our needs sometime like a large project to require several side participants to act coordinately. The problems that met in CAE projects can be summarized as below.

・ The whole image about complex and large-scale projects cannot be easily grasped by 2D drawings or verbal description. Some table scaled-models are very limited.

・ Planned projects are frequently modified to satisfy the need of all the aspects.

・ Project management during construction becoming difficult because of complex process.

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・ Multi-system running in city need a more feasible tool to display.

・ Landscape and environment evaluation trend toward a high level and cannot be realized only by imagining.

・Underground projects increase so that the unseen components arranging crowdedly.

3.1.4 Program languages of Virtual Reality [8]

1. VRML (Virtual Reality Modeling Language):

It is one of the network languages or a standard file format used for illustrating virtual space, especially for emphasizing the features of independent platform, augmentation, application in low brand-width network. At the time of VRML's popularity, a majority of users, both business and personal, were using slow dial-up internet access. This had the unfortunate side effect of having users wait for extended periods of time only to find a blocky, ill-lit room with distorted text hanging in seemingly random locations.

2. X3D:

X3D defines several profiles (sets of components) for various levels of capability including X3D Core, X3D Interchange, X3D Interactive, X3D CADInterchange, X3D Immersive, and X3D Full. Browser makers can define their own component extensions prior to submitting them for standardisation by the Web3D Consortium. Here are several applications, most of them being open source software, which natively parse and interpret X3D files, including the 3D

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graphics and animations. It is also expected to be a future standard language for 3D graphics.

3. Java 3D:

Java 3D is a scene graph-based 3D application programming interface (API) for the Java platform. It runs on top of either OpenGL or Direct3D. Compared to other solutions, Java 3D is not only a wrapper around these graphics APIs, but an interface that encapsulates the graphics programming using a real, object-oriented concept. Here a scene is constructed using a scene graph that is a representation of the objects that have to be shown. This scene graph is structured as a tree containing several elements that are necessary to display the objects.

3.1.5 Devices of Virtual Reality [6]

1. Head-Mounted Display, HMD:

It is a display device, worn on the head or as part of a helmet, that has a small display optic in front of one (monocular HMD) or each eye (binocular HMD). It mainly includes: 1) microphone which is used for communication. 2) Headset for receiving signals. 3) Head-Tracking Device for tracing the users‟ own action and they can transmit any messages of their motivations, locations etc back to the computers as well. 4) LCD Screen, which is belonged to the locus system.

(Fig 3.1) HMD normally applied in aviation, tactical, engineering, medical, gaming and sports.

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2. Force Feed-Back Devices:

It is an I/O tactile device and categorized as the following:

1) Shadow Dextrous Hand:

The Shadow Dexterous Hand is an advanced robot hand system that reproduces all the movements of the human hand and provides comparable force output and sensitivity.

2) Rumble Chair:

Thundering Audio Technology creates a true Force-Feedback sensation for unmatched interactive gaming.(Fig 3.2)

3. Data Glove:

It is a glove-like input device for virtual reality environments. Various sensor technologies are used to capture physical data such as bending of fingers. Often a motion tracker, such as a magnetic tracking device or inertial tracking device, is attached to capture the global position/rotation data of the glove. These movements are then interpreted by the software that accompanies the glove, so any movement can mean any number of things. (Fig. 3.3)

4. Space mouse:

This is a cheaper device among others. It is reformed to a 3D input device instead of the traditional 2D input technique. Users can move and rotate in the 3-dimensional space by the fingertips only. (Fig 3.4)It can also provide intuitive and precise interactive motion control of three-dimensional graphic objects in up to six degrees of freedom simultaneously.

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5. 3D glasses:

The illusion of three dimensions on a two dimensional surface can be created by providing each eye with different visual information. Classic 3D glasses create the illusion of three dimensions when viewing specially prepared images. The classic 3D glasses have one red lens and one blue. It is made of cardboard and plastic are distributed at 3D movies. Another kind of 3D glasses uses polarized filters, with one lens polarized vertically and the other horizontally, with the two images required for stereo vision polarized the same way. Polarized 3D glasses allow for color 3D, while the red-blue lenses produce a dull black-and-white picture. (Fig. 3.5)

6. Projection VR

Projection VR permits more users with 3D glasses to get into the virtual environment at the same time. Its principle requires a projector to make projection on a large screen and users can experience the effect by wearing the 3D glasses. Most of the projection VR can be found in amazement parks, museums or 360 degree projection movies.