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Motion constraints providing guidance for 3D navigation have recently been suggested as a way of offloading some of the cognitive effort of traversing complex 3D environments on a computer. We present findings from an evaluation of the benefits of this practice where users achieved significantly better results in memory recall and performance when given access to such a guidance method. The study was conducted on both standard desktop computers with mouse and keyboard, as well as on an immersive CAVE system. Interestingly, our results also show that the improvements were more dramatic for desktop users than for CAVE users, even outperforming the latter. Furthermore, the study indicates that allowing the users to retain local control over the navigation on the desktop platform helps them in familiarizing themselves with the 3D world.
Citation preview
Evaluating Motion Constraints for 3D
Wayfinding in Immersive and Desktop Virtual
Environments
Niklas [email protected]
M. Eduard [email protected]
Philippas [email protected]
CHI 2008 – Florence, Italy
2
Where am I? Where am I going?
3
How to Aid Wayfinding?
• Wayfinding: navigation to solve specific task– Performed on cognitive map– Poor map leads to poor performance
• Problem: aiding wayfinding by supporting cognitive map building– Motion constraints and guides– Example: sightseeing tour of new city
4
Cognitive Maps
Hotel
Tour Eiffel
Montmartre
Notre DameLouvre
Airport (CDG)
?
5
Supporting Cognitive Maps
• GC: Global coverage– Expose viewer to whole environment
• CM: Continuous motion– Support spatial relations
• LC: Local control– Learning by doing
Hotel
Tour Eiffel
Montmartre
Notre DameLouvre
Airport (CDG)
?
6
Virtual vs. Physical Worlds
• Why is wayfinding more difficult in virtual worlds?– Low visual fidelity– Mouse and keyboard poorly mapped to
3D navigation– Lack of sensorial cues
• High cognitive load on users
7
Reducing Cognitive Load
• Method: Immersive Virtual Reality– Full 3D input– Full 3D output
• But: No widespread use, expensive (?)
• Mouse and keyboard are standard
8
Guiding using 3D Motion Constraints
• Tour-based motion constraints (GC)• Smooth animation (CM)• Spring-based control (LC)
9
User Study
• Hypotheses– H1: Guiding navigation helps wayfinding– H2: Local control improves familiarization– H3: Navigation guidance has higher impact for
desktop than for CAVE
• Controlled experiment (mixed design)• Two experiment sites• 35 participants
– 16 (4 female) on desktop computer– 19 (2 female) on CAVE system
10
Factors
• Platform (BS): desktop or CAVE• Navigation (BS/WS): free, follow,
spring• Scenario (WS): outdoor, indoor,
infoscape, conetree• Collect distance, error, and time
11
Procedure
• Phase I: Familiarization– Create cognitive map (5 minutes)– Supported by guidance technique– Three target object types
• Phase II: Recall– Locate two targets on overhead map
• Phase III: Evaluation– Collect third target in world – No navigation guidance
12
Results – Summary
• Navigation method:– Free navigation: CAVE better– Motion constraints: desktop significantly
better (p < 0.05) [H1]
• Desktop platform:– Spring-based guidance gave better
accuracy than other methods [H2]– Navigation guidance more efficient than
free flight [H3]
13
evaluation error
0
0,05
0,1
0,15
0,2
0,25
0,3
follow free spring
no
rma
lize
d e
rro
r
CAVE
Desktop
average time per target
0
5
10
15
20
25
30
35
40
45
50
follow free spring
tim
e p
er
targ
et
(se
co
nd
s)
CAVE
Desktop
recall distance
0
0,05
0,1
0,15
0,2
0,25
0,3
follow free spring
no
rma
lize
d e
rro
r
CAVE
Desktop
Results – Details
14
Conclusions
• Navigation guidance based on tours– Improve cognitive map building
• Evaluation on desktop and CAVE– Navigation guidance on desktop
outperforms CAVE– Less focus on interaction mechanics
• Take-away message: removing (some) freedom in 3D navigation may actually help wayfinding!
15
Questions?
• Main findings:– Free-flight best on
immersive platforms– 3D guidance: desktop
outperform CAVE– Allowing local control
helped desktop
– Removing freedom improves performance
• Contact information– Niklas Elmqvist
– Edi Tudoreanu ([email protected])
– Philippas Tsigas ([email protected])