### “3-D” & Temporal GIS

```“3-D” & Temporal GIS
Longley et al.
latter part of Ch. 13
Horizontal sure, but ….
how to deal with elevation/depth or time
Vertical
Horizontal and vertical
Horizontal, vertical, and time
ArcScene 9
Demo
http://dusk.geo.orst.edu/gis/captivate_arcscene/arcscene_demo.htm
The Vertical Dimension
two very different ways of looking at
representations of the vertical
dimension (third dimension) in GIS
“2.5-D” and “3-D”
vertical dimension combined with
temporal query = “4-D”
Lab 7 on Temporal Mapping
Tutorial/Exercises 6-2 and 6-3
Use ArcCatalog not Windows Explorer!
The geodatabase
http://dusk.geo.orst.edu/gis/geodatabaseCampus.mp4
Time Dependence
dimension to spatial data, just as the
vertical dimension does
or may be added to 3 spatial
dimensions to give 4D
Coastal Evolution of OR/WA
Cross & Twichell, USGS Woods Hole in Wright (ed.) Undersea with GIS, ESRI Press, 2002.
Time and Geographical Data
computer science has dealt with time
dependence of records in databases
e.g., records may be valid only for limited times
geographical cases are more complex objects may have limited existence, but may also
move, change shape, and change attributes
database models for time? few “temporal
GISs” on the market
Tracking Analyst for ArcGIS
Dealing with Time in GIS
shape of objects same, but attributes
change (ESPN)
same shape, same attributes, but
boundaries between objects or locations
of objects change
Turn on/off or move
http://www.clockwk.com/centenniavid.htm
shapes of objects change through time
define a limited number of time "slices"
“2.5 D”
most common way of “doing 3D” in
commercial GIS packages
z value (normally elevation) is recorded as an
attribute for each data point (x,y)
z values can be used in a perspective plot to
create the appearance of 3 dimensions
not true 3-D representation because elevation
is not encoded in data structure, not in
topology
2.5 D Representations
attractive displays of topography and other
continuous surfaces from DEMs or TINs
perspective plots computed from any
viewpoint
additional layers "draped" over the surface
USGS Topography
“Coastal Terrain Model”
…a surface that integrates topography
Integrated Topo-Bathy Model
and bathymetry
Topography
Bathymetry
+
=
Satellite
Imagery
Draped on
Topo-bathy
model
A dense network of Wi-Fi infrastructure
viewed above the built environment of Salt
Lake City, Utah
(Courtesy Paul Torrens)
Boundary Representation
TIN is a 2.5 D type of B-rep
one value of z for every x,y
each object has faces, edges, points
Perspective Plot from TIN (2.5-D
B-Rep)
B-Rep of a Cave Passage
True 3-D
store data in structures that actually
reference locations in 3D space (x,y,z)
here z is not an attribute but an
element of the location of the point
if z is missing, object does not exist!
several z’s possible for a single x-y pair,
soundings in the ocean or atmosphere,
geologic logs of wells
3-D Applications
geological/geophysical exploration
engineering design of mines, quarries, dams,
reservoirs, etc.
scientific explanation of 3D processes such as
ocean currents or lava flows
“data driven” - may not necessarily know what
you will find in 3D
so the structure of the representation may
enhance types of analyses that can be performed
Fonseca, Mayer, and Paton in Wright (ed.) Undersea with GIS published by ESRI Press
Fonseca, Mayer, and Paton in Wright (ed.) Undersea with GIS published by ESRI Press
“Fledermaus”
Interactive Visualization Systems
www.ivs3d.com
http://dusk.geo.orst.edu/gis/captivate_ivs/ivs1.htm
http://dusk.geo.orst.edu/gis/captivate_ivs/ivs2.htm
http://dusk.geo.orst.edu/gis/captivate_ivs/ivs3.htm
Volumes
visualization of volumes
modeling of volumes
algorithms for 3D spatial analysis
simpler, more efficient, if data in a
volumetric form
Example two: Hydrothermal Plume model output
VTK/Java3D
allows volume
calculations,
rendering,
and analysis.
3D probe
● animation
● bathymetry
● multibeam
● Smith/Sandwell
●
Vance et al., NOAA Alaska Fisheries
Science Center
Becker, Science, August 27, 2010
Underwater Behavior of Humpback Whales:
Potential Entanglement in Fishing Gear
Stellwagen Bank National Marine Sanctuary - Ware et al., Center for Coastal and Ocean Mapping, U. of New Hampshire
Spatial Occupancy Enumeration
(SOE)
volume is divided into cubes or voxels
usually produced by converting from Breps (similar to converting vectors to
rasters in 2D)
mass, volume and surface area are
quickly computed as Boolean operations
[on (full) / off (empty)] or voxel counts
SOE of a Mine/Quarry
Surface Water
Runoff
Gold, Transactions in GIS, 2006
Commercially Available?
Research frontier
not too many truly 3D GIS packages on
the market
2- or 2.5D GIS linked to 3D modeling
package
You knew I had to mention it…
A 3-D representation of office and retail land use in London. The height of
the bars identifies ’rateable value’—a UK indicator of the value of the
property/real estate in the grid squares–that is dedicated to office and
retail functions.
Valuation Office Agency 2005)
An extruded 3-D map of Figure 13.16, embedded within a games engine
(Courtesy Andy Hudson-Smith)
A collaborative planning application in Second Life, using
elements of the Virtual London 3-D model (www.secondlife.com)
(Courtesy Andy Hudson-Smith)
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Sketch Ups and Touch Tables