Ben Simons, Daniel Mitchell, Roland Fletcher and Bernard Pailthorpe
| Quicktime
3.6MB mpeg 4.6MB |
Quicktime
14.2MB mpeg 9.3MB |
This animation shows the growth and decline of the city of Baghdad, from 750 A.D. until 1400 A.D. The White regions show the approximate size of bagdad for the given year. The red regions show areas of growth, and blue regions show areas of decline. The animation (as rendered for TV) runs at 10 years per second.
The Euphrates River runs through the centre of Baghdad, canals appear in brown. The city/town boundaries have been determined from the interpretation of ancient texts. Prof. Roland Fletcher can elaborate here!
Animation method
Nine Graphical Information System
(GIS) coordinate maps
(in Map Info *.mif format) were taken as input. Closed
polygonal regions were produced via
a perl
conversion script. To obtain the in-between boundaries, the edges from
the source and target regions were blurred, until each gap was closed.
The blur
was made brightest near the source edge, and darkest near the target
edge.
The boundary animation is then achieved by tracing boundaries of
gradually decreasing brightness.
This method produces a first approximation of the city movement, in that regions are grown in a direction which is normal to the orginal boundary curvature, and the speed is linear. Of course, this may not be exactly how the growth/decline occurred. Work is continuing in this area. One possible extension is to determine & apply stress functions to particular regions.
This method produces a first approximation of the city
movement, in that
regions are grown in a direction which is normal to the orginal
boundary curvature, and the speed is linear. Of course, this may not be
exactly how the growth/decline occurred. Work is continuing in this
area.
One possible extension is to determine & apply stress functions to
particular
regions.
3D Baghdad models
The individual image frames were taken from the above animation and loaded as slices into VoxelView which creates a volume, as shown below. Essentially time is now represented in the vertical z-axis.The time slices have also been exported to AVS and Houdini. Daniel Mitchell (VisLab) has produced several semi-transparent volume-slice animations in AVS/Express, and these will be shown here soon. An initial example appears below right.
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The movie on the left shows the 3D model rotating in the
horizontal
plane. The model used in this animation is currently 360,000 points
(120,000 polygons) which is fairly large. We're
experimenting with methods to reduce this complexity so
that we can produce a small VRML model which you can freely
rotate and zoom.
Other similar projects done in VisLab
Yuan-Ching
AVI 31MB or WMV 450KB
The Mongol Empire 1100 -1400 AD
The Mongol Empire animation is a simple outline on a satellite backdrop. These were the first animations using Houdini carried out for the TimeMap project (R. Fletcher and I. Johnson)
AVI 24MB
The Mughal Empire 1500 -1850 AD
The Mughal Empire animation is a later effort with
transparency -
note the areas under revolt as the empire stretches beyond its capacity
to control.
AVI 10MB