1	"Virtual Reality" Virtual Reality
2	History of Virtual Reality The term 'Virtual Reality' (VR) was initially coined by Jaron Lanier, founder of VPL Research (1989). Other related terms include 'Artificial Reality' (Myron Krueger, 1970s), 'Cyberspace' (William Gibson, 1984), and, more recently, 'Virtual Worlds' and 'Virtual Environments' (1990s). Today, 'Virtual Reality' is used in a variety of ways and often in a confusing and misleading manner. Originally, the term referred to 'Immersive Virtual Reality.' In immersive VR, the user becomes fully immersed in an artificial, three-dimensional world that is completely generated by a computer.
3	Terminology Rendering algorithms: painters, Scan-Line, Z-Buffer Texture Mapping: increase realization Bump Mapping: Using texture map to modulate the way light is reflected pixel by pixel Shadows: Geometric analysis of the spatial relationship between light sources and the object in a scene; Ray tracing: Excellent for realizing shadows, reflections, refractions slow for VR Radiosity: Simulate the internal reflections that arise when an interior is illuminated by light source. Color intensities can be stored and associated with the individual polygon. Work best for VR
4	Immersive VR Immersion is the sensation of being a part of Virtual Environment (VE) Immersion technologies increases the sensation of presence within the Virtual world, and for some people immersion distinguished VR systems for other real-time computer graphics systems.
5	Characteristics of Immersive VR The unique characteristics of immersive virtual reality can be summarized as follows: Head-referenced viewing provides a natural interface for the navigation in three-dimensional space and allows for look-around, walk-around, and fly-through capabilities in virtual environments. Stereoscopic viewing enhances the perception of depth and the sense of space. The virtual world is presented in full scale and relates properly to the human size. Realistic interactions with virtual objects via data glove and similar devices allow for manipulation, operation, and control of virtual worlds. The convincing illusion of being fully immersed in an artificial world can be enhanced by auditory and other non-visual technologies.
6	Stereoscopic Vision Stereoscopic Vision: Stereoscopic images are image pairs, which are directed to separate eyes by using special viewing techniques or equipment. The result is an illusion of a single actually three-dimensional image. The phenomena is based on the fact, that we see the world always from two slightly different angles simultaneously. This is process of mapping an image into corresponding position upon the two retains http://www.ioon.net/martian/stereo2.html
7	Depth Cues Stereopsis Cues Motion Parallax Cues Perspective depth Cues
8	"Technologies" Technologies
9	Head-Mounted Display (HMD) Houses two display screens and an optical system that channels the images from the screens to the eyes, thereby, presenting a stereo view of a virtual world. A motion tracker continuously measures the position and orientation of the user's head and allows the image generating computer to adjust the scene representation to the current view. As a result, the viewer can look around and walk through the surrounding virtual environment.
10	CAVE Automatic Virtual Environment The ACVE (Cave Automatic Virtual Environment) was developed at the University of Illinois at Chicago and provides the illusion of immersion by projecting stereo images on the walls and floor of a room-sized cube. Several persons wearing lightweight stereo glasses can enter and walk freely inside the CAVE. A head tracking system continuously adjust the stereo projection to the current position of the leading viewer.
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12	Vision Dome the VisionDome delivers a full-color, raster based, interactive display, with 360 degree projection a 180 degree field of view. The tilted hemispherical screen is positioned so as to fill the field-of-view of the participants, creating a sense of immersion in the same way that large-screen cinemas draw the audience into the scene. The observer loses the normal depth cues, such as edges, and perceives 3D objects beyond the surface of the screen. The dome itself allows freedom of head motion, so that the observer can change their direction of view, and yet still have their vision fully encompassed by the image.
13	Input Devices and other Sensual Technologies A variety of input devices like data gloves, joysticks, and hand-held wands allow the user to navigate through a virtual environment and to interact with virtual objects. Directional sound, tactile and force feedback devices, voice recognition and other technologies are being employed to enrich the immersive experience and to create more "sensualized" interfaces
14	VRML VRML provides three-dimensional worlds with integrated hyperlinks on the Web. Home pages become home spaces. The viewing of VRML models via a VRML plug-in for Web browsers is usually done on a graphics monitor under mouse-control and, therefore, not fully immersive. However, the syntax and data structure of VRML provide an excellent tool for the modeling of three-dimensional worlds that are functional and interactive and that can, ultimately, be transferred into fully immersive viewing systems. The current version VRML 2.0 has become an international ISO/IEC standard under the name VRML 97.
15	Applications Visualizing structures developed using CAD Training, specially where it is expensive or dangerous Visualize large building projects Surgical training, virtual organs Entertainment, virtual TV studio, children program. Virtual museum, historical buildings, and archaeological sites Another million and one other applications B-26
16	"Thank you" Thank you