Q & A on Virtual
Reality
A
: A global high-bandwidth communication network built for Virtual Reality type
communication (e.g. Muiltiple personnel Teleconferencing)
B : A US Army multiple tanks and helicopters simulation for training exercises in the same virtual enironment.
C : A global virtual reality stock exchange simulation network. User can get a virtual reality interface to the world's finacial database.
D : A continental stationary orbit satellite network for mobile VR applications.
B : A US Army multiple tanks and helicopters simulation for training exercises in the same virtual enironment.
C : A global virtual reality stock exchange simulation network. User can get a virtual reality interface to the world's finacial database.
D : A continental stationary orbit satellite network for mobile VR applications.
Q2. Which of the following(s) has / have been ignored but
is / are needed for effective VR applications? (
rating = B )
1.
fast interactive time.
2.
good graphic display.
3.
the sense of smell and
taste.
4.
force feedback.
A
: 1 only
B : 3 only
C : 1 and 3 only
D : 1, 2 and 3 only
E : All of the above.
B : 3 only
C : 1 and 3 only
D : 1, 2 and 3 only
E : All of the above.
1.
the simulators are of
higher cost than their real counterparts.
2.
addiction
3.
temperary nausea,
dizziness
4.
difficult to use
A
: 1 only
B : 3 only
C : 1 and 3 only
D : 2 and 3 only
E : All of the above.
B : 3 only
C : 1 and 3 only
D : 2 and 3 only
E : All of the above.
1.
A child playing a flight
simulator game on a PC.
2.
A drug designer viewing
a drug molecule via a Head Mounted Display coupled to the computer.
3.
A NASA operator
controlling a space module on the moon to pick up rock samples.
A
: 1 and 2 only
B : 2 only
C : 2 and 3 only
D : All of the above.
B : 2 only
C : 2 and 3 only
D : All of the above.
Q5. Which of the following relates most closely
to Virtual Reality with respect to the audiences ? ( rating = C )
A
: Science Fiction Books
B : Comedy Drama Play
C : Action films
B : Comedy Drama Play
C : Action films
1.
brightness control.
2.
focusing rings.
3.
frequency control.
4.
magnification button
A
: 1 only
B : 2 only
C : 1 and 2 only
D : 2, 3 and 4 only
E : All of the above.
B : 2 only
C : 1 and 2 only
D : 2, 3 and 4 only
E : All of the above.
1.
the simulator cockpit.
2.
the outside of the
simulator.
3.
the Computer Generated
Images (CGI).
4.
the latency time between
the heading of the plane and the pilot actually sees the image corresponding to
this position.
A
: 1, 3 and 4 only
B : 3 and 4 only
C : 3 only
D : 4 only
E : All of the above.
B : 3 and 4 only
C : 3 only
D : 4 only
E : All of the above.
Q8. What is the most important reason for
using Remot-Piloted Vehicle (RPV) in Military ? ( rating = C )
A
: To reduce the exposure of troops on hostile area.
B : The cost of manufacturing a manual vehicle is more expensive.
C : RPV can be made faster and their fuel consumption is also lower.
D : RPV can be made smaller, hence increasing stealth.
B : The cost of manufacturing a manual vehicle is more expensive.
C : RPV can be made faster and their fuel consumption is also lower.
D : RPV can be made smaller, hence increasing stealth.
Q9. Which of the following(s) can be categorized into the class
of Distributed Virtual Reality system? (
rating = B )
1.
A Boeing 747-400 flight
simulator.
2.
Medical Telepresence.
3.
Teleconference.
4.
Military Simulation.
5.
The game
"DOOM" played by a single player.
A
: 3 only
B : 2 and 3 only
C : 2, 3 and 4 only
D : 2, 3, 4 and 5 only
E : All of the above.
B : 2 and 3 only
C : 2, 3 and 4 only
D : 2, 3, 4 and 5 only
E : All of the above.
Q10. In Distributed Interactive Simulatoin (DIS), a
technique called Dead Reckoning is used. It introduces a
timestamp and a velocity factor into the message packets which are sent between
hosts. Which one of the followings best describes what Dead Reckoning does
? ( rating = E )
A
: Each host is now able to extrapolate an entity location and orientation etc.
without the need of constant update of messages.
B : Each host is now able to know for how long an entity will "live" in the virtual environment from the initialisation of that entity.
C : Each host is now able to determine the relative importance of their received messages. Priority is given to those with higher velocity factors or messages with higher time differences.
B : Each host is now able to know for how long an entity will "live" in the virtual environment from the initialisation of that entity.
C : Each host is now able to determine the relative importance of their received messages. Priority is given to those with higher velocity factors or messages with higher time differences.
Answers
A1. The correct answer
is B.
Explanation : During the 80's, the US Army introduced a VR tank simulator to train and test crews on theirM1 Abrams Main Battle Tank ( the right diagram ). Later about 200 of these simulators were networked together so that multiple tanks can fight together on the same virtual battlefield stored in the computer's database. By then it was known as SIMNET.
Today's SIMNET can link up to 1000 military units and it includes other fighting vehicles such as Apache helicopters and A10 "tank-killer" aircrafts. Experts believe it is a very effective and economic training tool.[3]
Explanation : During the 80's, the US Army introduced a VR tank simulator to train and test crews on theirM1 Abrams Main Battle Tank ( the right diagram ). Later about 200 of these simulators were networked together so that multiple tanks can fight together on the same virtual battlefield stored in the computer's database. By then it was known as SIMNET.
Today's SIMNET can link up to 1000 military units and it includes other fighting vehicles such as Apache helicopters and A10 "tank-killer" aircrafts. Experts believe it is a very effective and economic training tool.[3]
A2. The correct answer is B.
Explanation :
3 - the sense of smell and taste : smell and taste are extremely important for a VR system, not only do they help distinguish specific substances, but also they give a sense of reality to a situation. The absence of odor is a serious limitation of the current telepresence and training systems[1]. The reason why it is being ignored is that it is very hard to implement as many sensory cells need to be stimulated in order to provide the corresponding sense and tasteeffect.
Note that fast interactive time and good graphic display are not ignored but are not good enough due to the present computer technology while force feedback is quite good for most VR applications such as in flight simulator but it needs some improvement in some other applications such as the use ofminimally invasive surgical technique in medical telepresence where the scaling down of force applied by the surgeon is crucial for effective and safe operation.
Explanation :
3 - the sense of smell and taste : smell and taste are extremely important for a VR system, not only do they help distinguish specific substances, but also they give a sense of reality to a situation. The absence of odor is a serious limitation of the current telepresence and training systems[1]. The reason why it is being ignored is that it is very hard to implement as many sensory cells need to be stimulated in order to provide the corresponding sense and tasteeffect.
Note that fast interactive time and good graphic display are not ignored but are not good enough due to the present computer technology while force feedback is quite good for most VR applications such as in flight simulator but it needs some improvement in some other applications such as the use ofminimally invasive surgical technique in medical telepresence where the scaling down of force applied by the surgeon is crucial for effective and safe operation.
A3. The correct answer is D.
Explanation :
2 - addiction : as a result of the enormous power of virtual reality, people may find that the virtual world is so real that they do not want to go back toreality. If these people, especially children and teenagers, are not being controlled, they may get addicted to and prefer living in the virtual world, which may then cause a lot of social problems.
3 - temperary nausea, dizziness : virtual reality systems usually have a lag time between when the user moves and when the display is updated; users, accustomed to this lag, may become confused when they take the helmet off. Moreover, virtual reality creates an illusion of three dimensions, even though the screen actually remains at a fixed distance from a wearer's eye. This may disrupt depth perception later. As a result, cybersickness may be caused in which the patients will experience temperary nausea, dizziness etc.[1]
For the cost of the simulators, it is usually lower than that of their real counterparts as one of the main reasons of producing simulators such as the flight simulators is that it is cost effective -- for further details, please refer to section 2.1.1 of the article "Flight Simulation".
On the other hand, most VR systems are user friendly and very easy to use. For example, a flight simulator can be used in the same way as a real plane.
Explanation :
2 - addiction : as a result of the enormous power of virtual reality, people may find that the virtual world is so real that they do not want to go back toreality. If these people, especially children and teenagers, are not being controlled, they may get addicted to and prefer living in the virtual world, which may then cause a lot of social problems.
3 - temperary nausea, dizziness : virtual reality systems usually have a lag time between when the user moves and when the display is updated; users, accustomed to this lag, may become confused when they take the helmet off. Moreover, virtual reality creates an illusion of three dimensions, even though the screen actually remains at a fixed distance from a wearer's eye. This may disrupt depth perception later. As a result, cybersickness may be caused in which the patients will experience temperary nausea, dizziness etc.[1]
For the cost of the simulators, it is usually lower than that of their real counterparts as one of the main reasons of producing simulators such as the flight simulators is that it is cost effective -- for further details, please refer to section 2.1.1 of the article "Flight Simulation".
On the other hand, most VR systems are user friendly and very easy to use. For example, a flight simulator can be used in the same way as a real plane.
A4. The correct answer
is D.
Explanation : A major distinction of VR systems are the modes they are interfaced to the users. The modes are categorized into Video Mapping,Immersive System and Telepresence.[2]
Explanation : A major distinction of VR systems are the modes they are interfaced to the users. The modes are categorized into Video Mapping,Immersive System and Telepresence.[2]
The flight simulator
game is an example of Video Mapping. The player flies the
plane through a virtual space created in the computer.
The Head-Mounted Display is the ultimate form of VR interface. The designer is totally immersed in the virtual environment of the molecule.
The controlling of the space module is a form of telepresence. The cameras and sensors on the vehicle gives the operator enough visual and touch senses ( and perhaps audio, too ) to make him / her feel virtually there.[2]
The Head-Mounted Display is the ultimate form of VR interface. The designer is totally immersed in the virtual environment of the molecule.
The controlling of the space module is a form of telepresence. The cameras and sensors on the vehicle gives the operator enough visual and touch senses ( and perhaps audio, too ) to make him / her feel virtually there.[2]
A5. The correct answer
is B.
Explanation : The main feature of Virtual Reality is its ability for the participants to interact with one another. Films and books yield no power of interaction since everything is preset. Stage acting is a little better since the actors can respond to the audience reaction, which affects their performance.[3]
For further details, please refer to the article "The Philosophy of Virtual Reality"
Explanation : The main feature of Virtual Reality is its ability for the participants to interact with one another. Films and books yield no power of interaction since everything is preset. Stage acting is a little better since the actors can respond to the audience reaction, which affects their performance.[3]
For further details, please refer to the article "The Philosophy of Virtual Reality"
Explanation :
2 - focusing rings : The essential components of a Head Mounted Display (HMD) [4] are : 1) the housing, 2) head strap, 3) liquid crystal display (LCD) screens, 4) aspheric lenses, 5) focusing rings, and 6) video cable as shown in the right diagram. The focusing ring moves the aspheric lens closer or further relative to the LCD, to facilitate focusing of the image, and to adjust for accommodation variances between different users.
Brightness Control is not an essential component of a HMD. Usually, the display generated by the computer should have the optimal brightness for the viewer.
Frequency Control is for changing freqency for differnt channels and is one of the essential components for most electronic devices such as TV, radio etc. However, for a HMD, it is not needed to change the frequency for different channels as only one channel is needed because there is only one source of information to be displayed.
Most VR applications do not need magnification of the image. It is only needed in viewing some delicate structure e.g. in the operation of the patient's delicate internal structure such as the brain, eye etc. However, magnification is already done in the computer before the display is being generated on the display and so no magnification button is needed.
Back to question 6
A7. The correct answer is B.
Explanation :
3 - the Computer Generated Images : The current CGI is not good enough in providing a very high resoultion display. In order to let the user have a better sense of immersion in the virtual environment, it is crucial to provide a very good 3D display of very high resolution. Hence, improvement is needed.
4 - the latency time : In the current flight simulator[5], there is a time delay of approximately 0.06 second between the heading of the plane and the pilot actually sees the image corresponding to this position. This time delay is not desirable as we want the simulator to be highly interactive. Besides, a long time delay may cause the user to experience cybersickness[9].
Obviously, the outside of a flight simulator is not the main concern of making the flight simulator as it does not have anything to do with providing a better virtual environment. On the other hand, the inside of a flight simulator, at present, can actually be made identical to its real counterpart e.g. the flight deck of Airbus 320, Concorde etc. is being reproduced exactly as the one in a real plane[5]. So, no improvement on the current flight simulator cockpit is needed.
Back to question 7
Explanation :
3 - the Computer Generated Images : The current CGI is not good enough in providing a very high resoultion display. In order to let the user have a better sense of immersion in the virtual environment, it is crucial to provide a very good 3D display of very high resolution. Hence, improvement is needed.
4 - the latency time : In the current flight simulator[5], there is a time delay of approximately 0.06 second between the heading of the plane and the pilot actually sees the image corresponding to this position. This time delay is not desirable as we want the simulator to be highly interactive. Besides, a long time delay may cause the user to experience cybersickness[9].
Obviously, the outside of a flight simulator is not the main concern of making the flight simulator as it does not have anything to do with providing a better virtual environment. On the other hand, the inside of a flight simulator, at present, can actually be made identical to its real counterpart e.g. the flight deck of Airbus 320, Concorde etc. is being reproduced exactly as the one in a real plane[5]. So, no improvement on the current flight simulator cockpit is needed.
Back to question 7
A8. The correct answer
is A.
Explanation : The two main reasons behind the use of RPV in military are to reduce the exposure of human troops to hostile area where they may encounter enemy gunfire and to increase stealth of a vehicle.
However, the first reason is considered the most important since the exposure of RPV does not immediately threaten the risk of human lives.[6]
The cost of making an RPV depends on the nature of the vehicle. There are RPVs in the form of light tanks which are expensive but there are also RPVs which are battery powered light vehicles built primarily for "suicide" missions (hence should be made less expensive). The speed and fuel consumption characteristics of the vehicles also depends on this matter. Hence, answers B and C are incorrect.
Explanation : The two main reasons behind the use of RPV in military are to reduce the exposure of human troops to hostile area where they may encounter enemy gunfire and to increase stealth of a vehicle.
However, the first reason is considered the most important since the exposure of RPV does not immediately threaten the risk of human lives.[6]
The cost of making an RPV depends on the nature of the vehicle. There are RPVs in the form of light tanks which are expensive but there are also RPVs which are battery powered light vehicles built primarily for "suicide" missions (hence should be made less expensive). The speed and fuel consumption characteristics of the vehicles also depends on this matter. Hence, answers B and C are incorrect.
A9. The correct answer is C.
Explanation : In a distributed system[7], the existence of multiple computers, and the data stored on those computers, is transparent to the user. Distributed systems allow the collective resources of an entire network of computers to be used seamlessly, as though the user were accessing the data directly on their workstation. Virtual worlds can benefit greatly from distributed strategies. Not only can the processor load for upkeep and interaction within a virtual world be spread between many machines, but objects and data from across the network can be combined within a single environment. Distributed virtual realities would also facilitate multiple interactive users within the same environment.
2 - Medical Telepresence : In remote operation of medical telepresence, the surgeon and the patient may be distributed in different parts of the world, network is required for connection and hence it is a kind of distributed system.
3 - Teleconference : Participants in a teleconference may be distributed in different parts of the world.
4 - Military Simulation : It is possible to connect many, say tank simulators together into a vast network, so that one can interact with the other. For further details, please refer to the answer of question 1.
A Boeing 747-400 flight simulator is a single simulator which does not need to interact with the other systems. So it is not a distributed system.
A single player playing the game "DOOM" does not need to interact with the other computers (players). Hence it is not a distributed system. However, if several players playing "DOOM" on the computers connected by modems, it will be considered as a distributed virtual reality system because there will be interactions among all the computers being connected together.
Back to question 9
Explanation : In a distributed system[7], the existence of multiple computers, and the data stored on those computers, is transparent to the user. Distributed systems allow the collective resources of an entire network of computers to be used seamlessly, as though the user were accessing the data directly on their workstation. Virtual worlds can benefit greatly from distributed strategies. Not only can the processor load for upkeep and interaction within a virtual world be spread between many machines, but objects and data from across the network can be combined within a single environment. Distributed virtual realities would also facilitate multiple interactive users within the same environment.
2 - Medical Telepresence : In remote operation of medical telepresence, the surgeon and the patient may be distributed in different parts of the world, network is required for connection and hence it is a kind of distributed system.
3 - Teleconference : Participants in a teleconference may be distributed in different parts of the world.
4 - Military Simulation : It is possible to connect many, say tank simulators together into a vast network, so that one can interact with the other. For further details, please refer to the answer of question 1.
A Boeing 747-400 flight simulator is a single simulator which does not need to interact with the other systems. So it is not a distributed system.
A single player playing the game "DOOM" does not need to interact with the other computers (players). Hence it is not a distributed system. However, if several players playing "DOOM" on the computers connected by modems, it will be considered as a distributed virtual reality system because there will be interactions among all the computers being connected together.
Back to question 9
A10. The correct answer
is A.
Explanation : The three main obstacles to overcome in a distributed VR system and most communication applications are :
Explanation : The three main obstacles to overcome in a distributed VR system and most communication applications are :
Compatibility Bandwidth of channel Latency time
In VR apllications: The
first was tackled using a standard message packet to communicate between hosts.
The second and third can be solved by Dead Reckoning. For example, a car is
moving in a straight line: without Dead Reckoning the original host must update
the car's location constantly, putting a lot of traffic on the network , with
Dead Reckoning, each of the hosts is able to predict the motion of the car
without constant updates of information. From here updates are only required
when the car changes direction or speed.
Each entity from the original host runs 2 simulations: a full simulation and a dead reckoning simulation, if the two models diverge by more than a certain amount, then the host will broadcast / send messages to other hosts. This keeps them in line with what the entity is actually doing.
The effect of Dead Reckoning reduces an enormous amount of traffic on the network.[8]
Each entity from the original host runs 2 simulations: a full simulation and a dead reckoning simulation, if the two models diverge by more than a certain amount, then the host will broadcast / send messages to other hosts. This keeps them in line with what the entity is actually doing.
The effect of Dead Reckoning reduces an enormous amount of traffic on the network.[8]
TEST 2
Multimedia Applications-Technologies MCQs With Answers Set 1
1.Identify the concept of blending colors along the edges of letters to create gentle effect.
(a)Anti-aliasing
(b)Morphing
(c)Kerning
(d)Leading
(e)Cascading.
2.Acronym for VRML:
(a)Virtual Reality Modeling Level
(b)Virtual Reality Modulation Language
(c)Virtual Rate Modeling Language
(d)Virtual Reality Modeling Language
(e)Virtual Reality Marketing Language.
3.A Multimedia Presentation can be:
I.Linear.
II.Nonlinear.
III.Structured link.
IV.Web page.
(a)Only (I) above
(b)Only (IV) above
(c)Both (I) and (II) above
(d)(I), (II) and (III) above
(e)All (I), (II), (III) and (IV) above.
4.______________,from Macromedia can be used to create Postscript, TrueType and bitmapped fonts for MAC, PB, SUN includes a freehand drawing tool
(a)COOL 3D
(b)HotTEXT
(c)Robots
(d)Fontographer
(e)Smiley.
5.______________is a shorthand representation of music stored in numeric form.
(a)Digital Audio
(b)MIDI
(c)Audio Resolution
(d)Mono files
(e)LPC.
6.Converting bitmaps to drawn object is more difficult and is called:
(a)Dithering
(b)Morphing
(c)autotracing
(d)Leading
(e)Kerning.
7.What is the quicktime embedded HTML command?
(a)HFS
(b)Hues
(c)HREF
(d)HYPERLINK
(e)HYPERTEXT.
8.Identify the Test Release, which is typically for internal circulation only.
(a)Beta Release
(b)Gamma Release
(c)Polishing
(d)Sigma Release
(e)Alpha Release.
9.Identify the Macintosh character for <>
(a)(…)Ellipse
(b)?
(c)“ “
(d)=
(e)>=
10.Which of the following is not the style for the font?
(a)Shadow
(b)Outline
(c)Carve
(d)Bold
(e)Engrave.
Answers:
1.Answer : (a)
Reason:Anti-aliasing is the concept of blending colors along the edges of
letters to create gentle effect.
2.Answer : (d)
Reason:VRML stands for Virtual Reality Modeling Language
3.Answer : (e)
Reason:A Multimedia Presentation can be Linear or Nonlinear or Structured link
or web page
4.Answer : (d)
Reason:Fontographer can be used to create Postscript, TrueType and bitmapped
fonts for MAC, PB, SUN includes a freehand drawing tool
5.Answer : (b)
Reason:MIDI is a shorthand representation of music stored in numeric form.
6.Answer : (c)
Reason:Autotracing is converting bitmaps to drawn object.
7.Answer : (c)
Reason:HREF is the quicktime embedded HTML command.
8.Answer : (e)
Reason:Alpha Release is the Test Release, which is typically for internal
circulation only.
9.Answer : (b)
Reason:? ithe Macintosh character for <>
10.Answer : (c)
Reason:carve is not the style for the font.
Computer Graphics
Questions & Answers – Input Devices – 2
1. __________ allows screen
positions to be selected with the touch of a finger.
a) Touch panels
b) Image scanner
c) Light pen
d) Mouse
View Answer
a) Touch panels
b) Image scanner
c) Light pen
d) Mouse
View Answer
Answer: a
Explanation: None.
Explanation: None.
2. What is the disadvantage of the light pen?
a) It’s shape
b) They cannot detect positions
c) Accurate reading
d) Cannot detect positions within black areas
View Answer
a) It’s shape
b) They cannot detect positions
c) Accurate reading
d) Cannot detect positions within black areas
View Answer
Answer: d
Explanation: light pen requires special implementations and sometimes gives false reading due to background lighting in a room.
Explanation: light pen requires special implementations and sometimes gives false reading due to background lighting in a room.
3. ________ is used in graphics workstation as input devices to
accept voice commands.
a) Touch panels
b) Speech recognizers
c) Only a
d) All of these
View Answer
a) Touch panels
b) Speech recognizers
c) Only a
d) All of these
View Answer
Answer: b
Explanation: Through speech recognizers user can give voice commands.
Explanation: Through speech recognizers user can give voice commands.
4. What voice the use of voice system?
a) To initiate graphics operation
b) To enter data
c) Neither a nor b
d) Both a and b
View Answer
a) To initiate graphics operation
b) To enter data
c) Neither a nor b
d) Both a and b
View Answer
Answer: d
Explanation: The voice system input can be used to initiate graphics operations or to enter data.
Explanation: The voice system input can be used to initiate graphics operations or to enter data.
5. When a voice command is given, the system searches the
_____________for a frequency-pattern match.
a) Memory
b) Input data
c) Dictionary
d) Hard disk
View Answer
a) Memory
b) Input data
c) Dictionary
d) Hard disk
View Answer
Answer: c
Explanation: System searches the dictionary for frequency pattern matching.
Explanation: System searches the dictionary for frequency pattern matching.
6. The device which is designed to minimize the background sound
is
a) Microphone
b) Digitizers
c) Data glove
d) Joy stick
View Answer
a) Microphone
b) Digitizers
c) Data glove
d) Joy stick
View Answer
Answer: a
Explanation: Microphone is designed to minimize the background sound.
Explanation: Microphone is designed to minimize the background sound.
7. The quality of a picture obtained from a device depends on
a) Dot size
b) Number of dots per inch
c) Number of lines per inch
d) All the above
View Answer
a) Dot size
b) Number of dots per inch
c) Number of lines per inch
d) All the above
View Answer
Answer: d
Explanation: quality depends on these attributes.
Explanation: quality depends on these attributes.
8. Which of the following device is not the input device?
a) Trackball and space ball
b) Data glove
c) Only d
d) Impact printers
View Answer
a) Trackball and space ball
b) Data glove
c) Only d
d) Impact printers
View Answer
Answer: c
Explanation: printer is an output device.
Explanation: printer is an output device.
9. Which device contains thumbwheel, trackball and a standard
mouse ball?
a) Z mouse
b) Joystick
c) Mouse
d) Trackball
View Answer
a) Z mouse
b) Joystick
c) Mouse
d) Trackball
View Answer
Answer: a
Explanation: These 3 buttons are the Z mouse features.
Explanation: These 3 buttons are the Z mouse features.
10. Virtual reality, CAD, and animations
are the application of
a) Z mouse
b) Digitizers
c) Data tablets
d) Image scanners
View Answer
a) Z mouse
b) Digitizers
c) Data tablets
d) Image scanners
View Answer
Answer: a
Explanation: Application of Z mouse includes virtual reality, CAD, and animations.
Explanation: Application of Z mouse includes virtual reality, CAD, and animations.
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