virtual environments presence week 9 seminar \. presence presence: –refers to ‘being in an...
TRANSCRIPT
![Page 1: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/1.jpg)
Virtual Environments
Presence
Week 9 Seminar
\
![Page 2: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/2.jpg)
Presence
• Presence:– Refers to ‘Being in an environment
– Degree of presence in one environment relative to another
• Subjective presence– Response to questions about being there
– Verbal and conscious
– Evaluation of an experience
• Behavioural Presence– Observable responses to stimuli
– Responses to the events in the environment in question
• May be measured by subjective means or through observation
![Page 3: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/3.jpg)
Bodily Movement and Presence
• Main Hypothesis: – “ The environment relative to which major body movements are made has a higher
probability of being the dominant presence environment, other things being equal”– Examine influence of two factors
• Extent of body movement• Complexity of task• Major interest on body movement
– Motivated by two factors• “aha” type of experience• Construct interactive techniques
• Null Hypothesis• Scores are attributed randomly and independently
• Measured with questionnaires with six questions each on scale of 1 to 7
![Page 4: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/4.jpg)
Factorial Design
• Assess the extent to which body movement influences presence, particularly bending and head movement
• Scenario devised that would naturally induce subjects to use bending and head movements– Field of unusual plants or trees with large leaves distributed at
random through the field• Half subjects put into field where heights varied, other half
where heights were constant• Asked to move around field and count number of diseased
plants• More complex task also given
![Page 5: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/5.jpg)
Design
Virtual field Virtual lab
![Page 6: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/6.jpg)
Design(2)
• 20 subjects in total, between factorial design used within 5 subjects in each condition
• 15 male subjects, no subject had involvement in research or knowledge of purpose
• 150 trees in each scene, randomly distributed in a garden of dimension 90m-75
• Each tree had 16 leaves– A healthy one– One bad leaf– 4 bad leaves
![Page 7: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/7.jpg)
Procedure
• When initially put HMD on subjects were placed in virtual lab
• Carried out initial training tasks “in the lab”– Instructed to turn head, bend down, e.t.c to realise
these actions were possible
• Then went through door into field of plants and told to carry out tasks– 3 minutes time limit stated beforehand
• Then returned to lab, removed HMD and questionnaires administered
![Page 8: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/8.jpg)
Explanatory Variables
• Background information: gender and occupation• Pitch in degrees/sec• Yaw in degrees/sec• Roll in degrees/sec• Mean and standard deviation of hand height
above ground level
![Page 9: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/9.jpg)
Results
• Body movement• Variation of body height (bending and standing)• Degree of head colation
• ‘Tree height’ main source of variation for body movement, whereas task main source of variation for head colation
• Low variation tree field - no bending down but considerable head movement.
• Average head movement not significant between 2 tree groups – major difference was overall body movement
• Body movement measured by hand height
![Page 10: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/10.jpg)
Results 2
Variable(/s)
Tree 1
(low)
Tree2
(high)
Task Level 1
(simple)
Task Level 2
(complex)
Pitch Mean=3.4 sd=1.4
Mean =3.3sd =1.4
Mean= 3.7, sd = 0.9
Mean = 5.1
Sd = 1.1
Yaw Mean=12.3
Sd=3.7
Mean=10.1
Sd=3.5
Mean=9.4
Sd=3.3
Mean=13.0
Sd=3.1
Roll Mean=13.5
Sd = 4.1
Mean=11.2
Sd=3.7
Mean=2.6
Sd=0.7
Mean=4.0
Sd=1.7
€
±
Note: The differences within each pair of Task means are significant on a t test at 5% on 18 df),
![Page 11: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/11.jpg)
Analysis
• Task not as significant as interaction between gender and task
• Significant relationship between presence and body movement variables
• Positively associated with yaw• Negatively associated with vertical variation
![Page 12: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/12.jpg)
Conclusion
• Presence likely to be positively associated with amount of body movement
• Results of impact of type of task inconclusive
![Page 13: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/13.jpg)
Walking>Walking in-Place>Flying in Virtual Environment
• Previous Study:– Slater et.al 1995– Walking-in-Place Vs push button flying– Virtual treadmill– Neural Networks to analyze the tracked head motion
• Gains:– Virtual Walking has higher subjective sense of presence
than push button flying.
![Page 14: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/14.jpg)
Current Project Hypothesis: Real walking results in higher sense of presence• Current Study:
– Add Real Walking– Use Wide area tracker– Enhanced Graphics & Avatar representation
• Objectives:– Do Results of previous study hold true given more
recent technology?– To compare Virtual walking, Real Walking & flying with
respect to ease of Locomotion & subjective presence.
![Page 15: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/15.jpg)
Terminologies
• Flying:– Flying is done in the direction of gaze to make the Flyer
& Virtual walker groups match.
• Virtual Walking: – Participants reproduce the physical head motion
generated during actual walking, but without physical locomotion
• Real Walking:– Participants are free to walk around in the entire Virtual
scene as in real.
![Page 16: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/16.jpg)
Real Walking Implemented
• Implementing Virtual Walking:– Track user’s head & one hand using a custom optical
tracker– Track over a range of 10m x 4m with millimeter
precision– Two optical sensors view infrared LED’s on ceiling.– Tracked Position & Orientation updated every 1.5kHz– Tracker latency of 25ms, total latency 100mm
• Problems:– Watch the cables!!
![Page 17: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/17.jpg)
How does the world look like?
• The Virtual World– Divide tracked place into a training & experimental area.
(room with the virtual pit)– Modern Graphics Engine, 40000 polygons– More Detailed Avatar, 11000 polygons– Radiosity lighting & texture for almost half the polygons – Subjects looking down can see their virtual body, feet,
untracked left hand & tracked right hand.
![Page 18: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/18.jpg)
The task
• In the training room:• Instructions given to
– Travel to a certain point along the corridor– Grasp virtual objects
• In the experiment room– Walk to the chair
![Page 19: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/19.jpg)
How does the world look like?
![Page 20: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/20.jpg)
The Experiment
• Technology– Silicon, Onyx2 with 1 graphic pipeline, two raster
managers.– Four 195Mhz R10000 processors, 2GB main memory.– Scene Rendered using OpenGL, frame rate 30Hz
stereo– Viewing by V8 Head Mounted Display with VGA
resolution (640x3) x 480– Display consists of two1.3 inch active LCD
![Page 21: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/21.jpg)
Experiment 2
• Input– Joystick with four buttons, two were used in experiment, tracked by ceiling
tracker.
• Participants– 33 ‘naive’ subjects, grouped into virtual walkers, real walkers, flyers. 5
women, 6 men. & 11 ‘expert ’ subjects, 10 men, 1 woman
• Questionnaires– Simulation sickness questionnaires– Presence questionnaires– Oral sessions
![Page 22: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/22.jpg)
Conclusions & Results
• Conclusions– Confirm that presence is highly correlated with degree
of association with virtual body.– Presence is higher for real walkers than for virtual
walkers & flyers.
• Locomotion
![Page 23: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/23.jpg)
Results 2
• Subjective Presence– No significance difference in all groups– Association with virtual body, directly related to rating of
presence– Females have higher sense of presence than males
(play less video games)– For flyers & virtual walkers higher discomfort is created
by less sense of present but not the case for real walkers
![Page 24: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/24.jpg)
Improvements
• Cables are unsatisfactory, currently working on wireless• Real walkers are best for human scale space but not
cheap• Replace flying with virtual walking, when presence is
important, & inexpensive to implement• Avatar realism, worth investing on• Clothing identification very important for some• Investigate voice location e.g. give instructions through
HMD.
![Page 25: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/25.jpg)
The concept of Presence
“Perceptual illusion of non-mediation” Lombard and Ditton
The extent to which the person fails to perceive or acknowledge the existence of a medium during a
technologically mediated experience.
![Page 26: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/26.jpg)
Presence
“when the individual fails to perceive the medium throughout a technologically mediated experience..”
![Page 27: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/27.jpg)
Types of Presence
The sense of presence has been studied as some
Type of Presence:
Physical: Feeling of been located somewhere (else).
Social: Feeling of been (and communicate) together.
![Page 28: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/28.jpg)
Determinants of presence
• The extent and fidelity of sensory information. • The match between sensors and displays• Content factor• User characteristics
In order to improve the sense of presence we analyze theFactors that encourage or discourage the feeling of “being there”
![Page 29: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/29.jpg)
The extent and fidelity of sensory information
• the ability of a technology to produce a sensorially rich mediated environment.
• the amount of useful and salient sensory information presented in a consistent manner to the appropriate senses of the user.
![Page 30: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/30.jpg)
The match between sensors and displays
Refers to the sensory-motor contingencies, i.e. the
mapping between the user’s actions and the
perceptible spatio-temporal effects of those actions.
For example, using head tracking, a turn of the user’s head should result
in a corresponding real-timeupdate of the visual and auditory display.
![Page 31: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/31.jpg)
Content factor
Our ability to interact with the content and to modify it
• objects, actors, and events represented by the medium
• the user’s representation or virtual body in the VE
• autonomy of the environment, i.e. the extent to which objects and actors (e.g. agents) exhibit a range of autonomous behaviors
• Social elements, such as the acknowledgement of the user through the reactions of other actors, virtual or real, will be important for establishing a sense of social presence15
![Page 32: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/32.jpg)
User characteristics
• the user’s perceptual, cognitive and motor abilities (e.g. stereoscopic acuity, susceptibility to motion sickness, concentration)
• prior experience with and expectations towards mediated experiences
• willingness to suspend disbelief• various mental health conditions, like depression, anxiety,
or psychotic disorders, are also likely to affect an individuals sense of presence
![Page 33: Virtual Environments Presence Week 9 Seminar \. Presence Presence: –Refers to ‘Being in an environment –Degree of presence in one environment relative](https://reader036.vdocuments.mx/reader036/viewer/2022062408/56649f395503460f94c559ab/html5/thumbnails/33.jpg)
Relationship between presence factors