for Increasing Residential in the Downtown: 3D Modeling
May 12, 2004; no new models called for
at this point.
Models: General Comments.
Models: Particular Comments
Models are not reality: they are, at
best, an imitation of some small subset of structural characteristics of
Focus on the word "structural"--there is no
functional element to an abstract model unless one uses some algorithm
for introducing flow or some other function across that model.
When viewing 3D models one needs to focus
more heavily on the fact that these models do not replicate reality than
one needs to do with 2D models
When viewing interactive 3D models one needs
to focus more heavily on the fact that they represent structure than one
needs to do with static 3D models.
Models made for the taskforce involve all
of the above: some are 2D, some are 3D. Some are static; some
are animated and move but allow no direct user interaction; some are interactive
(virtual reality models).
There are numerous models available, showing
a variety of alternative scenarios. They are a response to comments
of the taskforce and others. See the cover page at http://www-personal.umich.edu/~copyrght/ddaheight/
and follow links to various models and articles about models.
These models were designed to serve as a starting
point for looking at various height alternatives in the DDA as a whole
in order to make decisions about height come to life at a global scale.
In facilitating decisions at that scale, the human mind is then left to
analyze related matters on this and on other topics. Thus:
They are useful for looking at alternative
height patterns for introducing tall buildings
They are best suited for looking at this sort
of pattern on parcels that are currently vacant or surface parking
They are reasonably well-suited for looking
at parcels that already contain buildings: different color shadings
can show buildings on top of buildings or existing buildings can be razed,
reducing this stage of model construction to the previous one.
The models presented to the taskforce show
both elements to illustrate the various directions one might take
Originally, the taskforce was presented with
two very different types of models: the highly general model and
a very detailed model. They chose only to look at the highly general
model, which is a good thing given the short time frame available in which
to do the modeling. The idea was to use this new planning tool in
conjunction with, and as a complement to, the wide array of existing techniques
so well employed by the many fine practitioners (planners, architects,
builders, and developers) around town and in City Hall.
Planning Staff and others in City Hall use
the fine output of the City GIS capability for many purposes. Thus,
the models were created in the same GIS used by them in order to create
a process that could be replicated by them using their existing software
GIS mapping done in the 3D modeling generates
square footage in association with the mapping. The modeled databases
were checked against City-generated databases. When the two were
close in value, it was assumed that the modeling process, as a modeling
process, was reasonable. Where there was discrepancy, conversation
with Planning uncovered the reasons and appropriate adjustment was made.
City contour maps were used to generate a
topographic surface as a "Triangulated Irregular Network" (a standard GIS
tool and one that has been employed in guidance systems apparently since
the time of the Persian Gulf War).
City aerials were used to create building
footprints and these were extruded, to heights from Planning, against the
The TIN may also be of use in further analysis,
as discussed briefly, that involves hydrological flows or air dynamics
(in conjunction with the extruded footprint files or any number of other
Parcels viewed as targets of opportunity for
development were only those that did not lie in the Allen Creek floodplain,
were not historic district parcels, were not on public land, and were not
church parcels. Checking of inclusion/exclusion relations is an ongoing
Target parcels were separated into categories
(an infinite number of partitions is available if one allows parcel splitting
and amalgamation). Two general categories were:
Vacant and surface parking parcels (yellow);
Huron Street parcels that were not yellow (blue); Liberty Street parcels
that were not yellow or blue (red); First and Ashley parcels that were
not yellow or blue (red); North and South Main (red); and S. University
Parcels generated from a simpler zoning map
that eliminates C2B/R, C1A, and C1A/R and assigns those categories to C2A.
That scheme also includes a T zone for taller buildings (see details enumerated
elsewhere on this site).
These models, of downtown Ann Arbor in
particular, have been emerging over the past two years. 3D modeling
as an urban planning tool is relatively new; a number of west coast cities
have successfully employed various aspects of it. There are links
to existing studies in various locations on this website. There has
been considerable opportunity for a variety of folks to study them during
that period. As human nature has it, though, that sort of in-depth
study that would best occur over a long period of time appears not to happen--reaction
takes place as deadlines approach. Therefore, some reaction is more
emotional than it is logical and that should be an expected outcome.
In a university setting we have the opportunity to set a sequence of mini-deadlines,
in the form of quizzes, homework assignments to hand in, and so forth to
overcome this sort of situation. My experience with reaction to 3D
models is that the learning curve proceeds as follows: intial reaction
is "WOW" or "COOL" and blind fascination with the mechanics of how the
model works. Some people never get over that stage. But, for
those who do, the next step is to feel a bit angry, as if they had been
duped--"but, it's not reality" or "but, that's not the way it really is"
or some such (right...at this point reassurance seems important...that
indeed the model was never intended to do all). Once this last stage
has been overcome, then real progress in use of modeling can begin..."how
can I use the model to extract information about, or visualize, X, Y, or
Z?" "What happens if X is the maximum building height?" "How can
I use a structural model in support of other models?" "How can I
use a structural model to free up valuable time to think about human or
cultural or other physical issues that the model does not (and cannot)
address." It is so nice to see that the taskforce is now, as a group,
moving forward (along with the early adoptors) on the top step of the learning
curve; naturally, members of the public as a group, who necessarily know
less about the process that the taskforce has undertaken, will not yet
be at the same point. (Please feel free to share the URL for this site
as you wish.) The final step is that the viewer of the model learns
to create his/her own models, thereby becoming free of any bias introduced
by an outside modeler: that my goal here--to train folks within the
City to create at least some of their own VR models so that they have flexibility
in using this planning tool along with the set of tools they already
have in their kit.
Models: Possible Next Steps
Create virtual reality models in detail
for the whole DDA and a general structural model for the whole City (subject
of major grant proposal in process between City and UM).
More specific to this particular effort
and independent of the effort above:
Work with Planning Staff to identify more
detailed interests along S. University (process initiated)
Work with Peter Pollack, Pollack Designs,
to integrate different approaches (mentioned at the last meeting)
Put sliders on building layers so user
may interactively adjust building height rather than relying on modeler
to do so (emphasis on user becoming self-reliant).
Create stochastic model (suggested by William
Kinley) based on likelihood of building being built on a site--needs field
work to create database.
Integrate this modeling effort with others
already in place (involving city files): activity underway.
Check accuracy of all files; in the final
analysis, the output is only as good as the input.
Initiate getting some staff members involved
in creating these models (process has begun).
Solstice: An Electronic Journal of Geography and Mathematics,
Institute of Mathematical Geography, Ann Arbor, Michigan.
Volume XV, Number 1.