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3D Visualization of Cadastre: Assessing the Suitability of
Visual Variables and Enhancement Techniques in the 3D
Model of Condominium Property Units
Thesis Defense
Ph.D. candidate: Chen Wang
Date: 2015/11/18

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Outline
 Context
 Problematic
 Research aim and objectives
 Methodology
 Research process and key results
 Conclusion and Contributions
 Discussion
 Future works
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Context
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 3D visualization in geospatial
domain
A part of many current solutions
A hot cross-domain research topic
 3D visualization in cadastre
Introduced for overlapping situations
Aiming 2D visualization deficiencies
Part of several pilot systems

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Context
 For cadastre, current 3D
visualization research is
insufficient
Around 10 papers focus on 3D
visualization of cadastre
 The third dimension in
visualization
Is a double edged sward
Is not only a technical problem
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Problematic
 Current experience in 2D
may be no longer applicable
to 3D visualization of
cadastre
Visual variables may/may not
performance the same in 3D
Enhancement techniques may/ may not
be helpful
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Research Aim
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Data Derived data 3D model Display User
perception
 The general aim is to improve the 3D visualization
of Cadastre
 From semiotics of graphic’s aspect
Feature a
Feature b
Symbol a
Symbol b

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Research Objectives
 To evaluate the suitability of visual variables and
enhancement techniques in the 3D visualization of
cadastre
Visual variables: size, shape, brightness, saturation, hue, orientation, texture
Enhancement: labeling, object detaching, highlighting
 To evaluate the suitability of transparency
 To compare the perceptual properties of visual
variables between 3D cadastre visualization and 2D
visualization
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Research Scope
 User: mainly notaries and notarial students
 Scenario: condominium with overlapping property units
 Decision making goal: delimitating property units
 Evaluation criteria of suitability: mainly usability
 A limited set of visual variables and enhancement techniques
 Do not consider the influence of 3D navigation
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Methodology
Cross-domain literature review
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Expert group evaluation
Two empirical test with the
cadastre user
Face-to-face interview
Online questionnaire
• Data
• User
• Tasks
3D geo-visualization Cadastre
• Concepts
• Theories
• Challenges
Compare perceptual properties
perceptual
properties in 3D
perceptual
properties in 2D

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Preliminary Evaluation
 Purpose
Contribute a brief insight of suitability
Limit the following empirical test
 Method
Expert group evaluation
Cognitive walkthrough
 Process
Identify 5 requirements
Construct more than 100 3D models
Viewing, accessing and discussing
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Represent the relationship between
3D legal units and 2D land parcels
Preliminary Evaluation Interview Questionnaire Comparison

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 Change the size of the boundary is feasible
 Add extra symbol with different shape is feasible
 Orientation is obviously infeasible
 Brightness and Texture are feasible but have
ambiguities sometimes
 Color (hue and saturation) is feasible
Preliminary Evaluation: Key results
11Preliminary Evaluation Interview Questionnaire Comparison

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Face-to-Face Interview
 Purpose
Verify visual tasks for delimitating property units
Evaluate the usability of visual variables and
enhancements
Understand notaries’ opinions
 Method
Combine the interview with empirical tests
 Evaluation criteria
Usability: effectiveness, efficiency, preference
12Preliminary Evaluation Interview Questionnaire Comparison

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Face-to-Face Interview
 Test settings
8 visual tasks
35 3D models
Video animation
Two types of question
 Interviewed with 4
notaries
In the notaries’ offices
Last one hour
With open discussion
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Associate building part with 2D land parcel
and compare their geometric limits
Preliminary Evaluation Interview Questionnaire Comparison

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Face-to-Face Interview: Key Results
 A list of eight notarial visual tasks
 Usability of visual variable
Brightness is marginal effective and not preferable
Color and texture is effective and preferable
Transparency is effective and marginal preferable
 Suitability of visual enhancement
Labeling should be placed inside or as close as possible to the symbol
Highlighting should always highlight all three dimensions
Object detaching affects the perception of displaced parts
14Preliminary Evaluation Interview Questionnaire Comparison

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Face-to-Face Interview: Key Results
 Notaries’ general opinions towards 3D visualization
of cadastre
They lack exprience with 3D visualization, but are really interested
Photo-realistic is not preferred
Too much color is dazzling
One of them prefers 2D visualization
They want to know the real value gaining
15Preliminary Evaluation Interview Questionnaire Comparison

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Face-to-Face Interview: A Retrospective Review
 Only interviewed 4 notaries, is the result valid?
5 participants is enough to contribute 80% of the design problems (Virzi, 1992)
3.2 users is an appropriate number (Nielson and Landauer, 1993)
Verified by multiple ways: literatures, examples, reasoning
Big improvement compare with many cartographic research
 The following experiment should:
Have more participants
Test different visual variable value settings
Enable freely 3D navigation
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!
Preliminary Evaluation Interview Questionnaire Comparison

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Online Questionnaire
 Purpose
Evaluate the usability of transparency for delimitating legal and physical boundaries
Investigate the influence of user’s attributes and transparency value settings
 Context
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c a
a. Simple legal
b. Simple physical
c. Legal & Physical
b
Boundary type
Preliminary Evaluation Interview Questionnaire Comparison

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Online Questionnaire
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 Using three levels of transparency
a. Simple legal 13%
b. Simple physical 36%
c. Legal & Physical 100%
alphaBoundary type
b ca
Preliminary Evaluation Interview Questionnaire Comparison

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survey.3dcadastre.com
Online Questionnaire
 A questionnaire website
 6 models, 12 tests
Different value settings
Same boundary set
Similar environment settings
 Questions
Effectiveness question
Certitude question
Respond time registration
 Statistical analysis
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Online Questionnaire: Participants
 Three group of participants
70 participants, 41 finished
 User’s attributes
Training background
Familiarity with cadastre data
Familiarity with 3D visualization
Color perception deficiencies
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Notary
Geomatics
Pure and applied Science
Social science
Preliminary Evaluation Interview Questionnaire Comparison

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Online Questionnaire: Key Results
 Transparency
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a. Simple legal 13%
b. Simple physical 36%
c. Legal & Physical 100%
alphaBoundary type
b ca
a. Simple legal 13%
b. Simple physical 36%
c. Legal & Physical 85%
Reduce the efficiency
a. Simple legal 36%
b. Simple physical 13%
c. Legal & Physical 100%
Reduce the certitudeThis design is usable
Preliminary Evaluation Interview Questionnaire Comparison

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Online Questionnaire: Key Results
 Notaries and
notarial students
lack experience
with 3D
visualization
 No experience
with 3D reduces
the certitude of the
user’s answer
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The participants’ experience with 3D visualization
Preliminary Evaluation Interview Questionnaire Comparison

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Compare Perceptual Properties
 Identify perceptual property involved in each visual
task
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Bertin (1983) Green
(1998)
Carpendal
e (2003)
Halik
(2012)
MacEachren
(1995)
Kraak &
Ormeling
(2011),
Slocum
(2009)
Garlandini and
Fabrikant, (2009)
Visual Task6: Associate building
part with 2D land parcel and
compare their geometric limits
Dissociative Selective Selective Visual isolation Nominal Saliency
Preliminary Evaluation Interview Questionnaire Comparison

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Compare perceptual properties: Key Results
 Synthesize perceptual properties in 3D and
compare with the conclusions in 2D visualization
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* Marginal
effective
Brightness
Visual variables Bertin (1983) Our result in 3D
Dissociative
Selective
Dissociative*
Selective*
Orientation Associative
Selective
Not effective
Preliminary Evaluation Interview Questionnaire Comparison

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Conclusion
 Empirically evaluate the
suitability of eight visual
variables in 3D cadastre
visualization
 Detailed examine the
usability of transparency
 Find the perceptual
properties differences of
visual variables between
3D and 2D
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Preliminary evaluation
Face-to-face interview
Online questionnaire

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Contributions
 The results could support the practice of cadastre
related 3D visualization
 Introducing empirical research methods to
cadastre visualization research
 One of the preliminary attempts to extend
semiotics of graphics into 3D
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Discussion
 Only test a subset of all possibilities
 Non-probabilistic sampling
 The limits of the theoretical foundation
 The result should be interpreted and used carefully
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Future research
 Improving the 3D visualization of cadastre
More usability tests with visual variables
3D cadastre visualization design principles
Pilot systems construction
Usefulness tests
 Investigating semiotics of graphics in 3D geo-visualization
Towards a 3D geo-visualization ontology
Semiotics of graphics in other 3D geo-visualization application domain
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“New symbol systems are being developed
constantly to meet the needs of a society
increasingly dependent on data. Once
developed, they may stay with us for a very
long time, so we should try to get them right “
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Colin Ware, 2012

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Acknowledgement
 Supervisor: Jacynthe Pouliot
 Co-supervisor: Frédéric Hubert
 Prélecteur: Francis Roy
 Evaluator: Stéphane Roche, Jantien Stoter
 Director: Marc Cocard
 François Brochu, Michel Bédard, Guy Delisle, Jean-Claude Simard
 Martin Leclerc, Vivien Fuchs, Marc Vasseur, Alborz Zamyadi, Abbas
Boubehrezh

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3D cadastre
 There is no standardized definition for 3D cadastre
that could fit all jurisdictions
 According to Stoter (2004), the term 3D cadastre
could refer to
Full 3D cadastre: Acceptance of the rights in 3D space. Infinite and finite
parcel volume
Hybrid: Register 3D situations integrated and being part of the 2D data set
3D tags: using current 2D cadastre, but with external references to the
representation of 3D situations
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Semiotics of Graphics
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Domain (Data)
Codomain
(Visual design space)
Visual mapping function
Feature a
Feature b
Feature c
Symbol a
Symbol b
Symbol c
Image (3D model)
Based on ISO 19117

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Cadastre data for visualization
 Only a subset of cadastre data
 We collected by
Researchers’ view: what they suggest
Institutions’ view: what they have achieved
Users’ view: what they expected
 There are many common items in different
cadastre visualization solutions worldwide
geometry of property units in condominium, the land lot the condominium
located, the surrounding land lots, the official measurements of the
property units, and legal/physical boundaries
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Evaluation criteria in HCI
 Appreciation, Trust and privacy issues, User
experience, User satisfaction
 Usability, User behavior, User performance,
 Intention to use, Perceived usefulness
 Appropriateness of adaptation, Comprehensibility,
Unobtrusiveness
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Cadastre users and usages
 A wide variety of users
By service division: property assessment, land management, and
geomatics
By their duty in each division: technicians, section leader, and domain
experts
 A wide variety of usages
Goals: taxation, construction permission, delimitating, urban development,
planning
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3D visualization challenges
 keeping the optimal information density
 Using the appropriate visual variables
 Occlusion management
 Spatial-relationship perception
The distance and position
3D topological relationship
 3D navigation and orientation
 3D cartographic standardization
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Visual tasks
 1. Identify the geometric limits of the property units
 2. Locate a specific property unit inside the building
 3. Distinguish the limits of the property units and the associated building
parts
 4. Distinguish the private and common parts of the condominium
 5. Associate property units with its surrounding units
 6. Associate building part with 2D land parcel and compare their geometric
limits
 7. Identify the official measurements of property units
 8. Background the condominium with its surrounding environment
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A Comparison between frameworks
 Brightness
Bertin: selective, dissociative
Carpendale: selective, associative
 Color (hue)
Bertin: selective, associative
Carpendale: selective, associative
 Garlandini and Fabrikant
Saliency problem
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Synthesize perceptual properties
 An example:
 Brightness
Interview with notaries
Task1 (selective): marginal
Task3 (dissociative): marginal
Task4 (dissociative): effective
Preliminary test:
Requirement 1 (dissociative) : marginal
Requirement 3 (dissociative) : marginal
Requirement 4 (dissociative) : marginal
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 The conclusion
Marginal selective
Marginal dissociative

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Statistic
 Randomized repeated measure
6 models, 12 tests
Randomized sequence
Same measurement in each test
 Mixed-effect model
The correctness: logistic regression
The certitude: generalized logit link with Laplace approximation
The response time: with log transformation and use linear regression
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The deficiencies of current theories
 Can’t describe visual variable quantitatively
(physical and perceptual)
 Can’t describe the dependencies between visual
variables
 Can’t describe the perceptual interaction between
them
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The deficiencies of current theories
 Color: Brightness, hue, and saturation
Current definition is according to a color space HSL or HSV
 There are more
RGB, CMY+K, CIEXYZ, CIELab, Munsell color system…
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Compare color space
 A comparison between HSV and HCL
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HSV (Same brightness) HCL (Same brightness)

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Compare color space
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CMYK RGB
CIEXYZ
CIELab

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BIM
 BIM: Digital representation of physical and
functional characteristics of a facility
 Visualization of BIM
Immersive, 3D, Virtual reality
Complex rendering
Physics engine (in near future)
Software: Artlantis, Lightscape, Accurender
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