3D in Visualization

i247: Information Visualization and
Presentation
3D in Visualization
Cecilia Aragon
Spring 2010
1
Acknowledgments
• Slides by Marti Hearst
2
Today
• 3D visualization
– 3D in scientific visualization
– Applying 3D to abstract data
• The PARC Information Visualizer and follow-ons
• 3D for data graphics
– Navigating in 3D space
– The debate: does 3D help?
• Cognitive abilities and 3D
• 3D vs 2D
– Case Study: Helping Helicopter Pilots (scientific viz)
3
3D and Scientific Visualization
• Visualizing information that is inherently 3D is a
special case of infoviz
– “Easier” in the sense that the 3D inherently makes sense
– Still, you need to choose what to show and what not to
show.
• Images from https://graphics.llnl.gov/flow.html
4
Chimera (from UCSF)
5
3D for Abstract Information
• Pioneering Work by Card and Robertson
– Had state-of-the-art graphics hardware; wanted to
see what happens when pushing the boundaries
– Motivated by Card & Moran’s theories of cognitive
architecture
•
•
•
•
Information Visualizer (PARC, 1992)
WebBook/Webforager (PARC, 1996)
Data Mountain (MS Research, 1998)
Task Gallery (MS Research, 2000)
6
Information Workspaces
• Objective:
– Decrease the costs for performing informationintensive tasks, or, alternatively, increase the scope
of information that can be utilized for the same cost.
• Method:
– Large Workspaces
– Make the immediate workspace virtually larger
– Real-Time Interaction
– Maximize the interaction rates
– Visual Abstractions
– Speed assimilation and pattern detection
8
7
Information Visualizer
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8
research.microsoft.com/~ggr/gi97.ppt
Web Forager
http://research.microsoft.com/ui/TaskGallery/index.htm
24
9
Task Gallery
(Robertson et al. 2000)
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10
Data Mountain
• Robertson, Czerwinski et al, 1998
• Follow-on to Information Visualizer
• Organizing bookmarks
using pile metaphor
• Uses:
–
–
–
–
Spatial organization
3D view with 2D interaction
Cartoon animation details
Subtle audio cues
• Debate:
– Is this better than 2D?
11
3D vs. 2D
• Cockburn & McKenzie ’02
– Results for prior work with 3D systems are
primarily negative for viz of things that are not
inherently in 3D, but really results are mixed
– Compared 2D, 2½D and 3D views of web page
thumbnails
– Did this for both physical and virtual interfaces
– Compared sparse, medium, and dense displays
12
3D vs. 2D: Cockburn & McKenzie ’02
13
3D vs. 2D
• Cockburn & McKenzie ’02
– Results:
• Time taken sig. increased through 2D -> 3D
interfaces
• Subjective assessment sig. decreased 2D -> 3D
• Performance degraded with denser problems
• 3D virtual interface produced the slowest times
• People prefered the physical interfaces
• People were better at using their spatial memory
than they expected to be
• There was a problem with the physical 2½D
display
14
The Role of Cognitive Abilities
• Leitheiser & Munro ‘95
– Summarizes the results of earlier psychological
research on spatial aptitiude
– Also summarizes work on effects of spatial aptitude
and UI use
– Presents a study comparing a GUI with a command
line interface, taking spatial abilities into account
15
The Role of Cognitive Abilities
• Leitheiser & Munro ’95
• Hypotheses:
– Users with high spatial ability would benefit more from the
GUI than those with low spatial ability (H1)
– Users with high verbal ability would perform better on
command line interfaces (H2)
• Tasks:
– Obtain system time, list files, look up a file update time,
open a subdirectory, move a file, copy a file, etc
– Between subjects GUI (Mac) vs. Command line (DOS)
• Findings:
– H1 supported
– H2 not supported
– Everyone did better on the GUI
• Low spatial ability users using the GUI required 90% of the
time needed for command line interface
16
3D and Data Graphics
• There have been lots of attempts to 3D-ify these
• Results seemed mixed
• Some modern versions of the ideas are here:
– http://www.oculusinfo.com/demos.html
– http://www.oculusinfo.com/softwareproducts.html
17
Interacting with 3D spaces
• Path-drawing for 3D walkthrough,
– Igarashi et al, UIST ’98
• Problem: interacting with 3D via 2D screens
• Solution: be clever about how to convert 2D to
3D based on what the user is likely to intend
18
Creating in 3D Spaces
• Teddy: A 3D Drawing System
– Igarishi 1999
http://www-ui.is.s.u-tokyo.ac.jp/~takeo/video/teddy.avi
http://www-ui.is.s.u-tokyo.ac.jp/~takeo/teddy/teddy/teddy.html
19
Other 3D Creation Tools
• Lots of other great ideas from Igarashi’s lab:
– http://www-ui.is.s.u-tokyo.ac.jp/projects/index.html
20
Sequences of Steps vs
3D + Animation
• Heiser, Phan, Agrawala, Tversky, Hanrahan ‘04
• Domain: assembly instructions
• Identify
– How people conceive of 3D assemblies
– How people comprehend visual instructions
• Validate
– Build automated instruction design system
– Evaluate usability of resulting instructions
Slides from Heiser et al.
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Ensure Visibility of Parts
•
•
•
•
Show parts added in each step
Show mode and location of attachment
Avoid changing viewpoint
Use physically stable orientation
Slides from Heiser et al.
22
Illustrate Assembly Operations
Structural diagrams
Action diagrams
• Use action diagrams rather than structural
• Use arrows and guidelines to indicate attachment
Slides from Heiser et al.
23
Improving Aviation Safety
with Visualization
• Aragon and Hearst, CHI 05
• Goal: reduce helicopter landing accidents
caused by invisible air turbulence
• Approach: use a new technology called lidar
and try to visualize its output
• Finding: it helped reduce simulated accidents
(!) but only when the visualization was made
as simple as possible.
24
Motivation
• Invisible airflow hazards cause aircraft accidents
–
–
–
–
–
Wind shear
Microbursts
Vortices (turbulence)
Downdrafts
Hot exhaust plumes
• Crash of Delta Flight 191 at DFW 1985 (microburst)
• NTSB database 1989-99
– 21,380 aircraft accidents
– 2,098 turbulence/wind related
25
Preliminary Usability Study
26
Preliminary usability study:
goals
• Assess efficacy of presenting airflow
data in flight
• Obtain expert feedback on presentation
of sample hazard indicators to refine
design choices
27
Usability study: low-fidelity
prototype
• Rhino3D (3D CAD modeling program)
– Easy access to ship models, ease of rapid
prototyping
– Chosen over 2D paper prototype, MS Flight
Simulator, WildTangent, VRML-based tools, Java and
Flash
• Series of animations simulating helicopter’s
final approach to landing
• Different types of hazard indicators
• Get pilot feedback and suggestions
(interactive prototyping)
28
Low-fi usability study screen
shots
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Low-fi usability study screen
shots
30
Low-fi usability study
participants
•
•
•
Navy helicopter test pilot, 2000 hours of
flight time, 17 years experience
Navy helicopter flight test engineer, 2000+
hours of simulator time, 100 hours of flight
time, 17 years experience
Civilian helicopter flight instructor, 1740
hours of flight time, 3 years experience
31
Low-fi usability study results
• All participants said they would use system
• Feedback on hazard indicators:
– Color: all preferred red/yellow only
– Transparency: should be visible enough to get
attention, but must be able to see visual cues behind
it
– Depth cueing: all preferred shadows below object,
#1 said shadows alone sufficient. #2 wanted
connecting line. No one wanted tick marks or
numeric info.
– Texture: #1, #2 didn’t want. #3 suggested striping
– Shape: Rectilinear and cloud shapes favored. Keep it
simple! Watch for conflicting HUD symbology.
32
Flight Simulation Usability Study
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Flight Simulation Usability Study
• Implement visual hazard display
system in simulator based on
results from low-fidelity prototype
• Advanced Rotorcraft Technology,
Inc. in Mountain View, CA, USA
– High-fidelity helicopter flight simulator
– Accurate aerodynamic models
• Use existing ship and helicopter
models, flight test data
• Simulated hazardous conditions,
create scenarios, validated by
Navy pilots and flight engineers
34
Flight Simulation Usability Study:
Participants
• 16 helicopter pilots
– from all 5 branches of the military (Army, Navy, Air
Force, Coast Guard, Marines)
– civilian test pilots (NASA)
– wide range of experience
• 200 to 7,300 helicopter flight hours (median 2,250 hours)
• 2 to 46 years of experience (median 13 years)
• age 25 to 65 (median age 36)
• No previous experience with airflow hazard visualization
35
Simulation Experiment Design
• 4 x 4 x 2 within-subjects design (each pilot flew
the same approaches)
• 4 shipboard approach
scenarios
• 4 landing difficulty levels
(US Navy Pilot Rating Scale - PRS 1-4)
• Each scenario was flown at all difficulty levels
both with and without hazard indicators
• Orders of flight were varied to control for learning
effects
36
Airflow Hazard Indicators in Simulator
37
Hypotheses
1. Crash rate will be reduced by the presence of
hazard indicator (LD 3).
2. Crashes will be eliminated by red hazard indicator
if a standard operating procedure (SOP) is given
to the pilots (LD 4).
3. Hazard indicator will not cause distraction or
degradation in performance in situations where
adequate performance is expected without
indicator (LD 2).
4. Pilots will say they would use airflow hazard
visualization system
38
Hypothesis 1 confirmed
Presence of the hazard indicator reduces the
frequency of crashes during simulated shipboard
helicopter landings (t-test for paired samples,
t=2.39, df=63, p=0.00985). 19% --> 6.3%
Landing Difficulty 3:
Crash Rate vs. Presence of Hazard
Indicator
0.25
Crash Rate
0.20
0.15
0.10
0.05
0.00
Absent
Present
Hazard Indicator
39
Hypothesis 2 confirmed
Presence of the red hazard indicator combined
with appropriate instructions to the pilot prevents
crashes (t=4.39, df=63, p < 0.000022). 23%->0%
Landing Difficulty 4:
Crash Rate vs. Presence of Hazard Indicator
0.35
Crash Rate
0.30
0.25
0.20
0.15
0.10
0.05
0.00
Absent
Present
Hazard Indicator
40
Hypothesis 3
No negative effect of hazard indicator. 8%-->8%
Landing Difficulty 2:
Crash Rate vs. Presence of Hazard Indicator
0.12
Crash Rate
0.10
0.08
0.06
0.04
0.02
0.00
Absent
Present
Hazard Indicator
41
Hypothesis 3 (cont’d)
Pilots believe hazard indicators were not
distracting (Probe 6 results).
6. The airflow hazard visualization distracted me
from the task of flying the aircraft.
Number of responses
12
10
8
6
4
2
0
Strongly
Disagree
Disagree
Neither Agree
Nor Disagree
Agree
Strongly
Agree
Pilot re sponse
6% Agre e , 94% Disagre e
M e dian 2, Std De v 0.7
42
Hypothesis 4 confirmed
Pilots would use the system (Probe 21 results).
21. I would use this display system if it were
available on my aircraft.
9
Number of responses
8
7
6
5
4
3
2
1
0
Strongly
Disagree
Disagree
Neither Agree
Nor Disagree
Agree
Strongly
Agree
Pilot response
81% Agree, 13% Disagree
Median 4.5, Std Dev 1.0
43
Analysis by Pilot Experience Level
• Same general trends -- but small sample size
• No significant difference between the groups
Crash Rate vs. Experience Level
0.25
0.2
Crash 0.15
Rate 0.1
0.05
0
Low
Mod
Hi
LD 2/No
LD 2/Haz
LD 3/No
LD 3/Haz
LD 4/No
LD 4/Haz
Pilot Experience Level
44
Analysis of Subjective Data
94% found hazard indicators helpful
Number of responses
18. The presence of the hazard indicators gave me
more confidence as to the state of the winds and
airwake on deck.
9
8
7
6
5
4
3
2
1
0
Strongly
Disagree
Disagree
Neither Agree
Nor Disagree
Agree
Strongly Agree
Pilot response
94% Agree, 6% Disagree
Median 4, Std Dev 1.0
45
Analysis of Subjective Data
Is motion (animation) helpful or distracting?
14. It would be distracting if the hazard indicator
showed airflow motion.
Number of responses
9
8
7
6
5
4
3
2
1
0
Strongly
Disagree
Disagree
Neither Agree
Nor Disagree
Agree
Strongly Agree
Pilot response
31% Agree, 63% Disagree
Median 2, Std Dev 1.1
46
Conclusions
• Flight-deck visualization of airflow hazards yields
a significant improvement in pilot ability to land
safely under turbulent conditions in simulator
• Type of visualization to improve operational
safety much simpler than that required for
analysis
• Success of user-centered design
procedure
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