Legible Cities:
Focus-Dependent Multi-Resolution
Visualization of Urban Relationships
Remco Chang Ginette Wessel Robert Kosara Eric Sauda
Department of
Computer Science
UNC Charlotte
College of
Architecture
UNC Charlotte
Bill Ribarsky
Department of
College of
Department of
Computer Science Architecture Computer Science
UNC Charlotte
UNC Charlotte
UNC Charlotte
2/19
Legible Cities:
Motivation
• While working on a graphics problem
to render large urban environments[1],
we realized…
• Visualizing a city should be more
than rendering its geometric
components
• There is a lot of information
directly tied to geographic
locations
• Question: how do people think
about a city?
[1] Remco Chang, Thomas Butkiewicz, Caroline Ziemkiewicz, Zachary Wartell, Nancy
Pollard, William Ribarsky. Hierarchical Simplification of City Models to Maintain
Urban Legibility. ACM SIGGRAPH 2006 Technical Sketch
3/19
Legible Cities:
Survey
How do you perceive the city?
• Describe New York City…
• Response 1: “New York is large, compact, and crowded.”
• Response 2: “The area where I lived had a strong mix of
ethnicities.”
Geometric, Information, View Dependent (Cognitive)
4/19
Legible Cities:
Demo
• System Demo
5/19
Legible Cities: Research Collaboration
Urban Visualization
• 3D Models of the City
Architecture
• Theories of City Design
and Spatial Structure
(Information) • City Conveys Meaning
• Information Display
through Visual Qualities
Embedded in the City
• User Interaction for
(View Dependence)• Individual’s Experience of
a City
Choosing Point of View
(Geometric)
6/19
Legible Cities:
Geometric – Theory of Urban Legibility
• Mental Sketch Maps of Cities
• Finding commonalities
• Elements of Urban Legibility
• Urban Theorist Kevin Lynch
Boston, MA
UNC Charlotte
Campus
Boston, MA
7/19
Legible Cities:
Geometric Modeling
• Definable Elements in the City
• “Imageability” Identity, Recognition, Meaning
• Spatial Understanding of the City using
Lynch’s Rules of Urban Legibility
Path
Edge
District
Node
Kevin Lynch. The Image of the City. Cambridge: MIT Press, 1960.
Landmark
8/19
Legible Cities:
Information Modeling – Iconology
• Robert Venturi and Denise Scott Brown
• Iconology
• Signs, Symbolism, Information
• Information Overlay
R. Venturi, D. S. Brown, and S. Izenour. Learning form Las Vegas.Cambridge: The MIT Press, 1977.
9/19
Legible Cities:
View Dependence - Experiential
• Gordon Cullen
• Understanding of Architecture is based on
optics, place, and content
• Experience of Movement,
Uncovering, and Texture
G. Cullen. The Concise Townscape. Oxford: The Architectural Press, 1961.
10/19
Legible Cities:
Interpretation of Urban Theories
• Geometric
• Hierarchical building clustering using the theory of Urban Legibility
• Information
• Matrix view shows information about building clusters
• Parallel coordinates show relationships between dimensions
• View Dependence (Cognitive)
• 2D translation of yellow sphere changes the position of focus
• Z-axis zooming changes the degree of focus
11/19
Legible Cities:
Coordinated Views
• Everything is designed around “clusters of buildings”
• Coordinate clusters using colors
• Proximity – Gradient from Red to Blue
• Selection - White
12/19
Legible Cities:
Querying
• Identifying areas with specific attributes
13/19
Legible Cities:
How To Use the System
• Using 2000 US Census Data
of Charlotte (Mecklenburg
County) NC
• Looking at:
• Ethnicity
• Citizenship status
• Income
• Housing Information
• etc.
• Other dimensions can be
used:
• Crime rate, traffic, etc
14/19
Legible Cities:
Scenario 1: Identifying Neighborhoods
• Task: Find areas around downtown Charlotte with high Hispanic
populations
• Select in the parallel coordinates view…
• Finding additional information about High Hispanic population regions
• Correlations with other dimensions…
15/19
Legible Cities:
Scenario 2: Segregation
16/19
Legible Cities:
Scenario 3: Comparing Regions
Davidson, NC
Downtown
Charlotte, NC
17/19
Legible Cities:
Expert Evaluation
• With 14 Expert Geographic Information System (GIS) Users
• Center of Real Estate at UNC Charlotte
• UNC Charlotte Urban Institute
• Charlotte Mecklenburg County GIS Office
• Charlotte Mecklenburg County Planning Department
• Charlotte Mecklenburg County School Systems
• Private Real Estate Developers
• Feedbacks are very positive…
• “Your tool is providing an on-the-fly, interactive way of noticing nearby
statistical data and their relationships”
• “Your focus area and peripheral areas are cohesively orientated…
Changing the level of detail in other software programs is
cumbersome [because it requires] running multiple repetitive
queries...”
18/19
Legible Cities:
Summary
• Urban Visualization
• Geometry
• Information
• View Dependence
• Contribution
• Interpretation and visual implementation of Architectural theories
• Implementing urban theories that are qualitative by nature
• View-Dependent, Multi-Resolution display
• Don’t have to zoom in and lose contextual information
• Allows the user to explore the city while retaining spatial
awareness
19/19
Questions?
Thank you!
www.viscenter.uncc.edu
20/19
Legible Cities:
Backup Slides
21/19
Legible Cities : Three Modalities
• “New York is large, compact, and crowded.”
• “The area where I live there has a strong mix of ethnicities.”
•Geometric
•Information
•Focus Dependent
22/19
Legible Cities:
Information Theory - Koolhaas
• Rem Koolhaas
• Economic and Political Issues
• Study of Symbolism
• Information Overlay
• City.org Approach
Rem Koolhaas. S,M,L,XL. New York: The Monacelli Press, Inc., 1998