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What is Virtual Reality?
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Clicking and dragging your way
through a 3D graphics application may be interactive, but it's not virtual
reality. It's not Virtual Reality because it's not immersive. "Immersion"
(or "presence") is the goal of virtual reality.
Immersion refers to your sense of engagement with the virtual model or
environment. When you're immersed, you focus directly on your subject and
disregard everything else. In virtual reality, an "immersive" application
lets you focus on the task at hand, so you don't deal with a mouse, or the
UNIX command line, or a GUI, or the fact that you're actually looking at
something made from digital bits instead of physical atoms.
Virtual reality essentially moves the computer out of your way, so you
can interact directly with your data or information. Unlike interactive 3D
graphics (which can consist of a series of still images coming off disk),
virtual reality lets you intuitively manipulate and navigate through a
real-time simulation of an object, or a process, or a place. |
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Where is Virtual Reality technology useful?
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Virtual reality adds value to virtually
any application where it's vital to experience spatial relationships, and
analyze, design, engineer and understand such relationships. Any project in
which 3D information must be navigated or closely examined will benefit
from virtual reality technology.
If you are working in two dimensions (web design, word processing,
etc.), you don't need virtual reality. |
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What are the different types of Virtual Reality configurations?
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Virtual reality technology can be
recognized by the presence of specific I/O devices which can be organized
into five categories, each creating a different impression of immersion.
These categories are not mutually exclusive:
Simulators use a physical mockup of vehicle with real controls
(steering, throttle, pedals, etc.), with which you can navigate through
virtual environment, and are ideal for applications such as pilot
training, driver training and games. Simulators can also involve multiple
participants.
Wearable devices provide direct, "body contact" input/output to
virtual models or environments through such devices as head-mounted
displays, boom-mounted displays, data gloves, data suits, haptic feedback
systems, motion platforms. These are ideal for digital prototyping, and
provide a highly immersive experience. However, they are limited to
single users.
The traditional monitor serves as a window into virtual world, with
which you interact using shutter glasses and 3D input. This is a low-cost
alternative to wearable devices, and are suitable for scientific data
visualization. They are also flexible (easily switch from monoscopic to
stereoscopic; easy keyboard access). This range of equipment includes
stereoscopic workbenches, tables and desks.
However, desktop devices suffer from the following drawbacks:
- they are based on the single user approach
- they do not provide a full immersion experience.
External devices are used to interact with your Version 5 session.
Those devices consist of a hand held equipment in which a tracker and a
set of buttons have been integrated. Hand tracking allows you to add a
virtual hand in the model to perform interactive functions such as
selection, command run or navigation.
Large virtual models and environments are projected onto flat or
curved screens, using such technologies as virtual reality walls (for
example, in Silicon Graphics Reality Centers). They can also be projected
onto vertical and/or horizontal surfaces in special chambers like
"caves" (for example, the Fakespace CAVE) or "walk-in domes".
These devices are the most sophisticated (and most expensive). They
are ideal for digital prototyping, provide high resolution, and allow
groups of participants to get involved and collaborate. They also require
a lot of physical space.
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Which Virtual Reality tools/technologies can be used in Version 5?
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In the myriad of tools and configurations
available, we can already identify a short-list of hardware useful for
navigating through or manipulating CAD data in real time, and capable of
providing some level of immersive experience:
Stereoscopic viewing of 3D images is built in Version 5. It can be
achieved either in active or passive stereo mode, depending on the
display system abilities.
In an active stereo display system, left eye and right eye images are
alternatively displayed on the screen at twice the refresh rate. An
active pair of glasses with two shutters working in synchronization with
the images is needed. Synchronization is often achieved using an infrared
emitter: the left eye shutter is closed when the right eye image is
displayed, and reciprocally.
In a passive stereo display system, left eye and right eye images are
displayed simultaneously on the screen. Image separation is performed by
filtering glasses using polarized light, for instance.
Stereoscopic viewing is extremely easy to implement. All hardware
manufacturers provide now graphic boards supporting OpenGL quad-buffered
stereo on Windows and UNIX based systems. Stereoscopic shutter glasses,
such as the CrystalEyes®
manufactured by StereoGraphics, provide a partially immersive experience
of digital mock-up visualization at lowest price investment. Another
possibility is to use a StereoGraphics Z-Screen mounted on top of a
standard monitor and viewed wearing non-expensive and lightweight passive
stereo glasses.
Head mounted display (HMD) afford a more immersive experience.
Equipped with position-tracking capability, it displays output imagery
based upon the position of your head.
To use a head mounted display, you can have either:
- an image generator computing left eye and right eye image
separately. Those are high-end systems
providing high performance and high quality 3D viewing
or
- an active to passive stereo converter such as Cyviz XPO2 box. This
solution allows you to use an head mounted display on any platform
supporting active stereoscopy.
In addition to head mounted display, a standard joystick can be added
to the virtual reality configuration, providing a very easy way to
navigate in the digital mock-up.
- Projector tables, projection walls, Immersive Rooms
Digital prototyping is served well by using a large projection systems
going from the single screen projection table, such as Fakespace Systems
ImmersaDesk or Barco Baron, to the multi-projector and multi-sided
projection room, such as the FakeSpace Systems CAVE or the Barco I-Space.
Version 5 also supports reconfigurable immersive display systems such as
the Fakespace RAVE or the Barco MoVE. Those systems are ideal for scale
one digital mock-up review or designing large assemblies and facilities.
Displaying the Version 5 on a single screen/single projector display
system requires no specific Version 5 service. You just need to plug your
computer graphic board video output to the display video input.
When you have a multi-projector display system, for instance as in a
TAN Holobench, you need a specific hardware
and specific Version 5 functionalities. Version 5 can support any kind of immersive environment,
that is to say any number of screens and projectors, in passive or active
stereo vision mode.
In such environments a better immersion is achieved using head
tracking, providing a 3D image depending on the exact user point of view,
as well as hand tracking for immersive interaction. To do so, Version 5
supports:
- Trackers such as Polhemus Fastrak®,
Intersense IS-900 and any devices compliant with the Fastrak Protocol
- Hand held devices with integrated tracker and buttons such as
Virtual Presence SpaceStick, Fakespace Neowand or Intersense Wand
- 3D Connexion Spaceball and Space Mouse which could dramatically
increase your work productivity by helping you manipulating the model
with your second hand. Please note that those devices are not specific
to virtual reality and can be used in any standard desktop
configuration.
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What does Version 5 support natively?
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The Version 5 infrastructure provides
support for:
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