Mumbai University > Information Technology > Sem 5 > Computer graphics and vitual reality

Marks: 10M

Year: Dec 2015

• VRML (Virtual Reality Modeling Language) is a language for describing three-dimensional (3-D) image sequences and possible user interactions to go with them.
• Using VRML, you can build a sequence of visual images into Web settings with which a user can interact by viewing, moving, rotating, and otherwise interacting with an apparently 3-D scene.
• For example, you can view a room and use controls to move the room as you would experience it if you were walking through it in real space.
• To view a VRML file, you need a VRML viewer or browser, which can be a plug-in for a Web browser you already have.
• Among viewers you can download for the Windows platforms are blaxxun's CC Pro, Platinum's Cosmo Player, WebFX, WorldView, and Fountain.
• Whurlwind and Voyager are two viewers for the Mac.

Simulation-based VR

• The first method is simulation-based virtual reality. Driving simulators, for example, give the driver on board the impression that he/she is actually driving an actual vehicle by predicting vehicular motion caused by driver input and feeding back corresponding visual, motion, audio and proprioceptive cues to the driver.
• The simulator normally consists of several systems as follows:

• A real-time vehicle simulation system performing real-time simulation of vehicle dynamics; motion, visual and audio systems reproducing vehicle motion, driving environment

• Scenes and noise sensed by a driver during driving; a control force roading system acting as an interface between the driver and the simulator; anoperator console for monitoring system operation; and system integration managing information and data transfer among subsystems and synchronization.

• The driving simulators have been used effectively for vehicle system development, safety improvement and human factor study.

Avatar image-based VR

• With avatar image-based virtual reality, people can join the virtual environment in the form of real video as well as an avatar. The proposed image VR system can handle two types of users.
• One can participate in the 3D distributed virtual environment as form of either a conventional avatar or a real video. Background of the video is effectively eliminated to enhance the sense of reality.
• A user can select his/her own type of participation based on the system capability. Users with capture board and camera may select a video avatar while others select a conventional computer graphics-based avatar.
• Avatar image-based VR now provides pretty good interaction environment between human and computer far beyond the conventional desktop computer systems.
• High-speed networks become available with the advance of network technologies.

Projector-based VR

• In projector-based virtual reality, modeling of the real environment plays a vital role in various virtual reality applications, such as robot navigation, construction modeling and airplane simulation.
• Image based virtual reality system is gaining popularity in computer graphics as well as computer vision communities.
• The reason is that is it provides more realism by using photo realistic images and the modeling procedure is rather simple.
• In generating realistic models, it is essential to accurately register acquired 3D data. Usually,camera is used for modeling small objects at a short distance

Desktop-based

• Desktop-based virtual reality involves displaying a 3-dimensional virtual world on a regular desktop display without use of any specialized movement-tracking equipment.
• Many modern computer games can be used as an example, using various triggers, responsive characters, and other such interactive devices to make the user feel as though they are in a virtual world.
• A common criticism of this form of immersion is that there is no sense of peripheral vision, limiting the user's ability to know what is happening around them.