URBS 250 FINAL*

Aa technique for placing 3d objects in pictorial space and illustrating the degree to which their forms appear to diminish in size as they recede into the depth of a drawing
Shows how a construction or environment might appear to the eye of an observer looking in a specific direction from a particular vantage point in space
Only approximates the way our vision actually functions

the projectors extending from the object to the observation station point (SP)

the projectors extending out from the object to the observation station point (SP)

sightline determining the direction in which the observer is looking

fixed in space representing a single eye of the observer

Horizon line: where a horizontal place passes through the centre of vision on the picture plane
Center of vision- C: the point where the central axis of vision (CAV) intersects the picture plane
Station point
Ground plane: horizontal plane or reference from which heights can be measured
Ground line (GL): intersection of the ground plane with the picture plane
Distance from GL to HL: equal to the height of the station point above the ground plane

60° Cone of Vision: ‘normal’ field of vision, to place principle aspects of subject
30° Cone of Vision: for menial distortion (eg on circular shapes)
90° Cone of Vision: acceptable for peripheral elements

If parallel to PP, a set of parallel lines in their orientation.Diminish in size according to distance but do not converge
Shapes parallel to PP retain their form but diminish in size according to distance
If perpendicular to PP, sets of parallel lines appear to converge toward the center of vision on the horizontal line

If oblique to the picture plane, a set of parallel lines will appear to converge toward a common vanishing point as it receded
If a horizontal set of parallel lines is oblique to PP, its vanishing point will always lie somewhere on the horizontal line
If a set of parallel lines rises upward as it recedes, its vanishing point ies above HL. if it slopes downward as it recededm its vanishing point lines below HL

Software, data, people, hardware, procedures

Physical computing components
Processors and memory: in user device or distributed via network
Interface: displays, mice, keyboards
For data input: scanners, digitizers, gps device
Data storage: servers, external hard drives, compact disks
Output: printers, plotters
As computing power has increased and cost has gone down, GIS has become accessible to a wider audience

Program and coding that provides the functions and tools necessary for storing, analysing, and displaying spatial info
Functions and tools
-Graphical user interface (UX)
-Database management
-Query and manipulation functions
Commercial products: very specialised and historically very expensive
Open source options: developed collaboratively and distributed free of charge

collection, management, analysis, visualisation, data

Made of rectangular cells- pixels- in a grid-matrix-
Each cell represents X meters in reality
Variation within the cell is lost
Best for representing continuous features or dense data
Eg land cover, elevations, temp

Features represented as coordinates (points) connected with straight lines:
Point: coordinated only (x,y) no dimensions
Line (‘polyline’): straight line connecting 2 or more points, 1 dimension
Polygon: area formed by connecting points,, 2 dimensions
Each feature has a unique ID used to join attributes
Best for features with discrete boundaries ( eg individuals, property lines, transportation, buildings)

frameworks for assigning location info to data

a surface of equal gravity formed by the oceans at rest and an imaginary extension of this surface under the continents. This ocean surface would be hilly because earth’s gravity is uneven, due to different mass at different locations

a smooth, simplified geometry (mathematical) used to approximate the geoid

1. Earth-centred datum
2. Local datum

preserves shapes (angles)
Meridians and parallels intersect at right angles
Area is always distorted in conformal projection

preserves area-distorts shape- particularly on the entire-world projections at the higher latitudes

preserves distance from a single location to all other locations

preserves directions from a single location to all other location
Direction from centre of the projection to all other points is preserved
Distortions are symmetrical around the chosen centre

No indication of quantities, intensities, or relative status
Also called ‘nominal’ or ‘categorical’
Choose distinctive and legible symbols that respect conventions
Main visual variables: shape, colour
lines
areas

Information about the relative status (importance, intensity, hierarchy) of phenomena
Midway between qualitative and quantitative data- cant add, subtract, divide
‘Ordinal’ data
Symbol size best to indicate relative size quantity

Information expressed numerically
Interval data: have arbitrary zero, can add or subtract but can’t multiply or divide
Ratio data: have true zero
Continuous data
Phenomenon occur in a ‘blanket’ but the info available arises from sample points
Discrete data
Phenomenon linked to specific and separate locations
Visualising quantitative data with lines
Not a very common symbol to represent data in thematic maps. Mostly related to movement in flow maps
Absolute quantities
Data is presented directly, not as proportion, ratio or average
Density measures and other ratios
Data is normalised, presenting values as a relative proportion, ratio or average

Represent the are by distorting the geometry of the feature itself
Technically a diagram not a map. Uses data from geographic areas and arranges the symbols in

Graphical excellence, visual integrity, maximising the data-ink ratio, and aesthetic elegance

Cognitive maps: internal conceptiopns of space, stored in someones mind; their spatial cognition
Mental maps: externalized cognitive maps- via drawings etc

Focus on physical aspect of the city
Paths, nodes, landmarks, edges (linear elements not considered paths), districts

1000: yellow- residential
2000: red- shopping, business
3000: purple- industrial, manufacturing and waste-related
4000: social, institutional, or infrastructure related

Redlining, gentrification

Rent control, social housing, community land trusts, inclusionary zoning

Classes of symbols: point, line, area
Visual variables: size, shape, tone, texture, orientation, colour

principles/laws of human perception that describe how humans group similar elements, recognize patterns and simplify complex images when we perceive objects
Theory of visual perception: “the whole is greater than the sum of the parts”
Closure, common fate, continuity, figure-ground, proximity, similarity, smallness/area, symmetry

a tool used to analyze and categorize community form and character
defines a series of zones that transition from sparse rural farmhouses to the dense urban core.

first citywide zoning code in the United States

proposed after the Equitable Building was erected in Lower Manhattan in 1915

Defined zoning districts specifying:
Separation of uses
Building envelopes (height, bulk, and area restrictions)

Asking participants to take photos of some aspect of their experience of the city (postove, neg, where certain activities/feelings/ etc occur)
Photos are then used as a departure point for interviews

Spatial data: representation of spatial features
Attribute data: descriptive info about features (eg pop, address, often in tables)
Traditionally spatial data and attribute data are stored separately then ‘joined’ for display or analysis

Projection surfaces:
Cylindric:Like wrapping a piece of paper around the earth, Best for equatorial or low latitudes
Conic: Like wrapping a cone around the earth, Best for midlatitudes with east west orientation
Planar: Projection onto a flat plane, Commonly used in polar regions

Conformal, conic (normal, secant)
Preserves shape and distance but not area
Good for areas with east-west extent
Commonly used for maps of canada

Conformal, cylindrical (transverse, secant)
Most common
Update on the standard mercator in order to map satellite imagery
Preserves shape but not direction
Distortion minimal at meridian but great outside the zone: best for narrow regions

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